Safe lean cruise.

[paulg23]

Any idea how lean I can run in closed loop cruise? I see people on other forums running 17:1 on cruise. Would this be an issue for te 6A13TT?

[foxdie]

I'm running 15.2 on mine with no issue whatsoever :)

I did some research and noticed the Evo boys are running 15.6, so I chose 15.2 as a safe middle ground. It's noticeably added a couple of MPG, how much I can't tell because I've gotten 250 miles out of a mixture of inner city driving, tuning the car at 1.2 bar boost (so lots of WOT) and about 75~ miles of steady motorway / dual carriageway driving.

[Nick Mann]

I had a wierd issue a couple of years ago where my car was leaning slowly on cruise. I never really fully understood why, but the bottom line was the car seemed to be coping fine at 17 AFR at 80mph. I noticed it going wrong at 18.something. I'd be happy to give it a go at 16.0 next time I have the chance to play, but I obviously can't guarantee what you'll get!

[paulg23]

Thanks for that. I can adjust mine from the dash but limited to a max of 16.7 at the moment. Will crank it up and see how she runs.

[adaxo]

What we should look at on lean AFRs ?? temps?? or overall performance?? mine is running at 15.2, 15.8 @ steady motorway cruise, I didn't change any settings on my MTX-L wideband, run like that since first day fitted. Drop to 11- 12 at WOT.

[Nick Mann]

I would imagine temps and knock, but I'm no expert. I'd think that lean burn gives a fast burning mix, with potential for more heat and detonation like burning. I've no idea how quickly you would notice the effects of all that - hopefully before the engine melts!

[adaxo]

That what I was thinking myself, and heat shouldn't be an issue on steady say 70 mph run?? or I'm wrong??

[paulg23]

I would imagine that the heat generated at cruise is going to be nothing compared to that generated at WOT. It may burn hotter running lean but the cooling system still wont have much to handle.

[lateshow]

It's a shame that im using PLX wideband as that one doesn't have the option to change the output signal so only thing I can do is try open loop. Would have to drive a full tank to see does this affect anything. I tried this once but idle was giving me problems. With stock injector scaling I was gettin ~15.5 @ cruise (stock fuel maps in that area) and +17 at idle. I even tried to adjust idle to 13.8 and still was getting 17. Strange. My Bosch wideband unit is now about 3 years old, I think it would need a new sensor. I still cant believe running lean gives much advance.....
My other car, the Gdi can get +23 AFR:s at idle and works nicely. :)

When datalogging with lean mixture I tried to see if there was difference in the fuel consumption but saw nothing.

[foxdie]

I would imagine that the heat generated at cruise is going to be nothing compared to that generated at WOT. It may burn hotter running lean but the cooling system still wont have much to handle.

Agreed, unless you factor in slow moving traffic, if you're driving steadily at 15-20 mph, the ECU is still going to try and achieve what AFR you set it to, and this may lead to overheating if you've got it set excessively lean (at a guess, 17+), but I believe the radiators will kick in long before any problems happen :)

Also, for those reading thinking "Don't engines go bang if they run too lean?", the answer is yes, but only under heavy load (such as WOT or accelerating up a hill), and in these circumstances the car changes to "open loop" mode where it uses a fuelling table instead of just trying to hit a target. Suffice to say, it's quite safe to lean out your cars cruising AFR by a small amount.

[paulg23]

I was surprised how little pedal movement it takes to drop out of closed loop. Driving at 70 mph on the A1 if you 'touch' the pedal to compensate for going up a slight hill it goes open loop. Are most cars this sensitive?

[Davezj]

If you can remap your ecu and know a lot of us can.
you can change what AFR you want at what RPM in open loop, so could you lean out the reagion at motorway crusing for a bit more economy.

does the fuel map take into account what gear you are in, with respect to the afr to target?
if so then 5th gear 2500-3000 revs AFR can be leaned out quite a bit.
but if it does not take into accout what gear you are in then doing this will be a bit dodgy.

it has been a while since i looked at me ecu map and you tend to forget how it is all linked together, which table affect what, etc, etc.

what do you think.

[lateshow]

Ok, some results. Drove today to work with closed loop and back home with lean settings. It goes around 15.2 when doing 80km/h, when doing hundred it approaches 14.8. When going downhill it leans out to 16 sharp and so on. It seems that momentary consumption can be lowered when going downhill. Datalogged everything and did some calculations. On the way to work my consumption was 10.38l/100km and back my consumption was 9.93 l/100km. The actual numbers are a bit lower. So yes, something can be done but needs a little tweaking. For example now im getting far too rich mixture with little boost pressures, however there are some parts where I need to make it richer. Heard some strange noise from the engine bay when accelarating on the way home, sounds like knocking but knock sensor picks nothing up (sensor is working however, got sometime 2 knocks when going with full boost, as usual) It goes 11-11.5 now boost.

The car feels somehow smoother and quiter (exhaust) because the mixture stays about the same ( lambda causes a huge loop)

What i've done so far: first took 5% off the injector scaling value
then leaned the map in power area to ~11.5
leaned engine temp vs fuel enrichement

[MackTheKnife]

Tried 15.7 for part of my trip to work today (75kms, mostly freeway). On an long uphill section of the F3 freeway I was losing power and the car couldn't even maintain speed in closed loop running.

Had to pull over and change the switch over point, decided to go back to 14.7 and see if there was any other issue. Once I did that it ran fine. I'll try some other settings to see what I can get away with on that hill, it seems a good tester. I'll have results of 15.5 tomorrow.

[Kenneth]

were you logging AFR and knock at the time? Without knowing exactly what was happening, it is hard to point to the AFR itself. If you were getting knock and the ECU was pulling timing you would rapidly lose power. Likewise if the ECU was making some assumptions on the AFR based on O2 feedback when the AFR was not actually 15.7 (Which narrow band would not be good at determining)

[MackTheKnife]

were you logging AFR and knock at the time? Without knowing exactly what was happening, it is hard to point to the AFR itself. If you were getting knock and the ECU was pulling timing you would rapidly lose power. Likewise if the ECU was making some assumptions on the AFR based on O2 feedback when the AFR was not actually 15.7 (Which narrow band would not be good at determining)

I was indeed, no knock whatsoever at the time. AFR fluctuated between 15.2 & 16, guessing the hill is a bit too steep for that afr.

I have a Zeitronix ZTX-3 in place of my narrowband and have the EvoScan GPS on my dash so was getting live data. I had no traffic around me so could keep an eye on things. Had a Knock Count of 2 at one point earlier in the trip, nothing showed up at the time.

The hill is a steep one, it needed 4th gear to keep 120 km/h in my 2008 Civic and my old 1982 Suzuki Sierra with it's 970cc engine needed 2nd gear to get to the top of the hill. The Legnum was always fine in 5th with tonnes of grunt to spare except for that one episode this morning. I'll keep experimenting, it seems the perfect place to test this out.

Granted that the Legnum is a daily driver that does about 600 km a week, a few MPG will make a difference.

[Kenneth]

And you are sure it was in closed loop? I would have thought the load required in that situation would put the car into open loop running.

You could be correct in that it is just a bit steep for that AFR. Try setting the switch point to 15.2 and see if that works. As I understand it, ~15.2 produces highest exhaust gas temps so should be best for efficiency.

[MackTheKnife]

And you are sure it was in closed loop? I would have thought the load required in that situation would put the car into open loop running.

You could be correct in that it is just a bit steep for that AFR. Try setting the switch point to 15.2 and see if that works. As I understand it, ~15.2 produces highest exhaust gas temps so should be best for efficiency.

Was definately in closed loop, AFR's went to low 14's/high 13's as soon as it went into open loop. Plus open loop had no trouble with the hill.

Will just change the switch point to 15.2 for a while, thanks Kenneth!

[lateshow]

This is why open loop works fine, I can tune it so that uphill takes it back to 14.7 and seems to work perfectly for me. Uphill loads are about 70-100 and downhill is 0-40. Downhill = near to 16, openroad = 15.2 uphill = 14.7 . It seems that it can create enough power downhill with much leaner mixture but uphill seems to be the problem point, i can now get momentary consumptions of 5-6 litres when going downhill. 8-10 open road and little over 12 uphill. Standard is about the same but you dont get so much benefits going downhill because mixture stays "too rich".

[MackTheKnife]

Ignore what I wrote above. Turns out my new fuel pump doesn't sit as low as my stock one. Looks like it may have been a mild case of fuel starvation.

[Beastlee]

I run mine, with my mods, at 15.2 closed loop. This has had no detrimental effects on the knock or EGTs as far as I can see, even during slow traffic, it passes MoTs wihtout the thrashing previously needed too. I just did 265 miles to 45L of fuel with mostly 80mph motorway driving so mid 20s mpg, no lack of power either as the BMW 5 found out during my one moment of weakness.

[foxdie]

I just did 265 miles to 45L of fuel with mostly 80mph motorway driving so mid 20s mpg

Okay.. I'm running 15.2 AFR and exactly the same as you I've just got over 300 miles to 45~ litres (around 30 MPG) :)

[Beastlee]

Jase it all depends on the driving style, road types and overall combined consumption though. The last 65 miles of mine was stop/start and round camp so will have dropped the overall economy drastically at that point. :p

[lateshow]

I'm doing about 9.2 litres/100km on 80-100km/h, nice. Beastlee. have you monitored you EGT?

[Shtiv]

I ran open loop everywhere for a while and was runninng about 15.5 at really low loads (20%ish), 15.2 at around 40% load and 14.7 by 80%, it ran O and I got some fuel benefit, about 5%....

[Beastlee]

Lauri, I unfortuanately don't have the facility to monitor them.

[lateshow]

Lauri, I unfortuanately don't have the facility to monitor them.


so we cant say for sure what the EGT does, because I think my engine runs a little bit hotter now than it used to...

[Nick Mann]

Why do you think the engine is hotter?

Coolant temp is measured by the ecu, quite accurately. Are you seeing a significant change there? It would be difficult to quantify, due to the thermostat still opening and closing at the same temp and the weather having an effect on the cooling of the car too.

[Beastlee]

I noticed yesterday that evoscan can log egt, there was a definite reading but i didn't think a VR-4 had a sensor.

[Nick Mann]

You are right, Lee, the VR4 doesn't have an EGT sensor!

[Beastlee]

Hmm, wonder what it's reading? It's not a constant anyway.

[MackTheKnife]

Been running 15.2 for a few days now, mostly 75 mph (120 kph). Car has been fine even on the steepest of hills. Looking forward to seeing how fuel economy improves next fill. No knock to report, car has been running sweetly.

[lateshow]

Torque convertor seems to do it's lockup faster than it used to, however i've changed the engine mounts at the same time which can have an effect too.

[lateshow]

Been running 15.2 for a few days now, mostly 75 mph (120 kph). Car has been fine even on the steepest of hills. Looking forward to seeing how fuel economy improves next fill. No knock to report, car has been running sweetly.

If you guys are running in closed loop, what kind of formula are you using for narrowband output???

[paulg23]

If you guys are running in closed loop, what kind of formula are you using for narrowband output???

I just set the NB output to 1 volt if the AFR is less than 14.7:1 and set it to 0 volts if the AFR is 14.7:1 or greater. I can move the AFR point from a dashboard control.

[MackTheKnife]

If you guys are running in closed loop, what kind of formula are you using for narrowband output???

I have a Zeitronix ZT-3 wideband hooked up.

I attached the stock O2 to the outside of the exhaust and put the wideband in it's place. The heater wires for the old O2 sensor need to be hooked up, otherwise you may get a check engine light.

I checked the wires on the old O2 plug for continuity to see which two were for the stock O2 sensor heater and then checked the other two wires where the O2 plugs into to see which was earth.

I ended up cutting both the sensor feedback and earth wires on the stock O2 sensor about an inch and a half from the plug. Then I attached the purple cable narrowband O2 emulation wire from the Zeitronix unit to the blue cable of the old O2 sensor (which was the sensor feedback wire on mine). The Zeitronix Unit also needs to be hooked up to switched power & earthed (I picked the ciggie lighter power wire because it's handy to where I mounted the Zeitronix unit).

Then all you need is a USB to Serial cable (which I got with my EvoScan GPS thing) and a Laptop. On the Zeitronix software, there's a menu item to change the Narrowband switching point, change it and you're done.

I believe the bloke who designed the Zeitronix Unit has a Galant VR4, not sure if his is an 8G one though.

[paulg23]

I removed my narrowband completely and don't get an engine check light.

[foxdie]

I removed my narrowband completely and don't get an engine check light.

Not even after 20-30 mins of driving? The ECU won't require a signal for a couple of minutes on startup because it knows the sensor has to heat up first.

[Nick Mann]

I don't think that has much to do with it, Jason? The check engine light would be appearing because the ecu thinks the heater for the sensor is open circuit. The stock sensor won't read accurately if it is not hot enough, if I understand it correctly.

Anyway, if the ecu is getting the narrowband signal where it expects, the only reason for a CEL is because the heater is open circuit.

[foxdie]

My heater circuit is currently open (oh my!), no fault code on my end, but I am inputting a simulated narrowband input from the LC-1 / MTX-L controller.

[apeman69]

No CEL if you disconnect the heater circuit so don't even worry about it.
Tried this with narrowband emulation connected and not connected, no CEL. No difference how long car is idling or driving.
ECU can't be checking for sound heater circuit (on PFL auto at least).

Sent from my Huge Brain using MyFingers :)

[paulg23]

No CEL at all. Done about a 1000 miles with it like this.

[lateshow]

With open loop there comes a situation where going downhill AFR goes 16-20. I've got 14.4 on the smallest load column. Should I be worried? Has Kenneth examined closed loop, how does it function? Because it seems that when using only open loop the car is more eager to turn injection off. Fuel consumption was 9.6 l /100km with the first tank (29.4 MPG) Most of this was driving @ 100kph, a part driving 80kph, very little city driving.

[Kenneth]

Is that from wideband? If you don't have your foot on the accelerator, you should be getting maximum lean (injectors off).
If you DO have your foot on the accelerator then that is a bit on the lean side...

No, I haven't really looked at the closed loop section in the ECU.


With open loop there comes a situation where going downhill AFR goes 16-20. I've got 14.4 on the smallest load column. Should I be worried? Has Kenneth examined closed loop, how does it function? Because it seems that when using only open loop the car is more eager to turn injection off. Fuel consumption was 9.6 l /100km with the first tank (29.4 MPG) Most of this was driving @ 100kph, a part driving 80kph, very little city driving.

[lateshow]

Yes that is from wideband, i have my foot on accelerator when going down very steep hills so I'm thinking if it goes on /off with injectors somehow (the actual momentary AFR isnt between 16-20, it is more like 15.5 and then injectors off and the same loop again and the wideband reacts to it that way) OR then there is some point between load 0-10 where open loop doesn't function well and it drops the AFR to too lean for bigger value of time and it will break my engine somehow?

[taylor]

I had a microcontroller in my car to read the 0-5v output from the wideband and simulating a narrowband on a output pin. I could adjust the switching poing by changing the code, I drove frome christchurch to auckland (~1000KM) with it targeting between 16.5 and 17.

Fule consumption wasnt bad, got about 570km to a tank, not bad considering I did alot of passing

[MackTheKnife]

Thanks to all that confirmed that removing the O2 sensor heater wires won't trigger a CEL.

I left them connected after reading feedback from Evo owners, but now I can shed a few grams of surplus weight from the car next time it's off the ground.

[phosty]

I had a microcontroller in my car to read the 0-5v output from the wideband and simulating a narrowband on a output pin. I could adjust the switching poing by changing the code, I drove frome christchurch to auckland (~1000KM) with it targeting between 16.5 and 17.

Fule consumption wasnt bad, got about 570km to a tank, not bad considering I did alot of passing

That's pretty good consumption - assuming a full 60L tank that's nearly 27 mpg. I'm interested to know more about your micro-controller gadget though - I have a PLX wideband (to replace an LC-1 that dies on me). Unfortunately the PLX units don't allow you to change the narrowband switch point in software like the Innovate LC-1 does - PLX tech support said you need to change a resistor value on the circuit board which isn't ideal.

When I did have a working LC-1 I did play with the switch point (mainly trying to get my emissions down for MOT time). I discovered that while I could move the idle lambda point slightly after a certain point further change had no effect. I wasn't sure if the ecu doesn't have some code that looks at the O2 trim levels to check if they start getting too far from the ideal and then limit them? Has anybody else noted similar?

[paulg23]

I can adjust my narrowband switch point from 14:1 to 17:1. the ECU seems to handle this OK. Its a PFL Legnum so I assume it has a 7201 in it.

[Nutter_John]

Having seen paul's gadget I was very impressed with it

[lateshow]

Having seen paul's gadget I was very impressed with it

You're referring to his car, right? ;)


When Low Fuel trim hits ~5% or -5% it is maxxed out and at that point ecu cannot give more or less fuel in closed loop mode. We discovered this as someone accidentally used wideband signal for ecu-> result too big voltage-> ecu sees that its always too rich-> Fuel trim goes to maximum negative value and mixture is all over the place.

I've noticed that my car's exhaust fumes are really smelly now and im doing only 15.1 at idle. One fact is that catalytic converter sits at my storage now. I think that targetting to 16-17 is dangerous. I'm alreaydy worried about mine when it goes to 16 when slowing down. And the car feels maybe a little bit more sluggish than it used to when not doing full boost. It seems that going from closed loop to open loop creates a certain effect as the mixture suddenly becomes richer. Like when you accelerate a bit first it uses closed loop and then it goes quite lean 13.5-14 with little boost (as stock). Now it hits almost instantly 13-> 12. Bloody hell, have to get miself an innovate. :)

[paulg23]

I assume the ecu can only change the fuel trim when in closed loop. Does it keep and use this trim figure for open loop? I assume it doesn't.

[phosty]

Paul or Taylor - can you elaborate on your respective 'gadgets'? Are they simple/cheap enough to build?

[paulg23]

Paul or Taylor - can you elaborate on your respective 'gadgets'? Are they simple/cheap enough to build?

I'll put some pics of mine up tomorrow. It uses a PIC microcontroller and an LCD display. Reasonably simple circuit.

[Nutter_John]

you are under selling it Paul , look real good (well once din'd up )

[paulg23]

you are under selling it Paul , look real good (well once din'd up )

Thanks for that John. I'll put details up tomorrow and some pictures and info regarding other things it can be made to do.

[lateshow]

I'll put some pics of mine up tomorrow. It uses a PIC microcontroller and an LCD display. Reasonably simple circuit.

Im interested too as i only have the PLX. Yes, fuel trim_LOW isn't used in open loop mode.

[paulg23]

This is it so far. Pulled apart an old car radio to use as the chassis. At present it displays the contents of the LPG tank and the AFR ratio. The green button switches between petrol and LPG, the control on the left sets the closed loop AFR and the switch lets me choose between AFR, boost pressure or MPH for the main display. I will be adding a performance monitor to it soon, a sort of cut down GTech device to measure acceleration.

It uses a OEM6 lambda controller from Tech Edge to get the lambda which is then converted to AFR.

The closed loop AFR adjustment is limited at the moment by the software but could be set anywhere the lambda sensor can read. (7.0:1 to about 50:1 but I've limited it to somewhere sensible).

[lateshow]

Paul, Start producing these items ? :) What about adding average fuel consumption there. I'd be willing to pay quite a lot D:

[Nutter_John]

Exactly what I said to Paul :)
We even spoke about it doing boost control as well

[paulg23]

We even spoke about it doing boost control as well

Boost control should be fairly easy. John, remind me how the current system works please.

[adaxo]

Paul, Start producing these items ? :) What about adding average fuel consumption there. I'd be willing to pay quite a lot D:


Something similar is already on the market, even fitted in Galant:

http://www.youtube.com/watch?v=J-N1iQiscVU

here is ongoing upgrade

http://www.youtube.com/watch?v=r1CM7jNkzWc

[phosty]

Something similar is already on the market, even fitted in Galant:


Interesting again - I didn't think the 8G VR4s gave enough OBD data for these mpg gadgets to work with? Or is it picking up speedo and injector signal directly?

Edit - ahh, found their webpage:

http://www.telwis.pl/universal-trip-computer-utcomp-p-119.html

Looks like it needs calibrating to get the mpg figures. Guess it won't be that accurate then.

[lateshow]

Hell yeah, im buying this thing if the ship to finland! Calibrating isn't a problem, then it becomes accurate as the actual fuel consumption says how it goes. Just need to find a place where one can solder this into ecu wires and which wires it needs.

[lateshow]

Here's a little video of my vr4 http://lateshow.1g.fi/kuvat/vr4/py%F6r%E4nkulmat/04092011011.mp4

[swinks]

Looks like it needs calibrating to get the mpg figures. Guess it won't be that accurate then.

Wrong!
I've seen 5 different UKP's (version 1.0) in Galants so far. Very popular gadget in PL. It takes signal from VSS and injector #1. First time use only needs calibrating signals from (vss and injectors) due to different size of tyres, wheels etc. Since then it's job done.
At the moment producer (known as "kaczart" in Polish Mitsi forum) is working with me on putting afr and vacuum/boost and imperial figures. It's ready beta version available only in 2 specimens both in my hands. Within next week or two me and Paul (psbarham) will do trial runs to smooth afr and vacuum readings and give feedback to manufacturer.
Once happy with new soft it will be available new version 2.0 also targeting UK market and performance cars.

So, Adam (adaxo).... actually you had spoiled all plans on putting ready product on the market. You big mouth! /pan

[lateshow]

Swinks: Do you think they will ship to finland? We are thinking about ordering a bunch of these devices. Does this need any other wires then vss and injectors apart from the normal power and ground wires? Does this monitor the amount of fuel?

[swinks]

Lauri, my advice is just wait few weeks for finalized ver. 2.0. Current product is only Polish version and producer is reluctant to sell abroad at this stage. I'm in touch with kaczart and he will consider selling multiple orders abroad.
Due to signals... as below:
- vss signal
- injector #1
- battery 12V
- acc 12V
- ground
- analog wideband 0-5v
- analog 0-5v map sensor
- analog temp sender signal (for oil, coolant, etc purpose)
- digital temp sensors (3 signals: ground, 12v, signal) for custom use (inside passenger cabin, and external weather temp)
- analog 12v input signal (for cooling fan working signalisation)
- signal and warning of driving lights switched on (some countries requires all year lights on)
- warning buzzer
- remote switches (4 wires)

That what I remember.
Give me few days and I'll post more details in separate thread. I'm just back to UK (today morning) and haven't got time yet to unpack my vr4...

[lateshow]

Ok, thanks for the info. I shall anyway try ordering from that webshop..... Im so damn eager, and I have one N/A car that doesnt need boost meter, actually it could do with a AFR since it's a GDI :D

[swinks]

Oh... well... yes, ver. 1.0 is good for you, then.
Here are useful tips how to fit in Galant:
http://forum.mitsumaniaki.pl/viewtopic.php?t=14477&postdays=0&postorder=asc&start=630
page 43.

[lateshow]

Oh... well... yes, ver. 1.0 is good for you, then.
Here are useful tips how to fit in Galant:
http://forum.mitsumaniaki.pl/viewtopic.php?t=14477&postdays=0&postorder=asc&start=630
page 43.

Thanks lad, just ordered and he said he'll send it tomorrow. Nice. :)

[adaxo]

So, Adam (adaxo).... actually you had spoiled all plans on putting ready product on the market. You big mouth! /pan

Sorry about that/hammer, but i got no crystal ball here, and I got not idea what is goin on behind steel courtain. :curtain:
I waiting for ver 2.0 myself and will be ordering this kit when is ready, but now Im not sure what you are saying, you got any sort of exclusiveness of this product?, you will be organising any sort of GB when ver 2.0 is ready?

Sorry again I've got no intention to destroy your plans or anything,:coat

[swinks]

Im not sure what you are saying, you got any sort of exclusiveness of this product?, you will be organising any sort of GB when ver 2.0 is ready?

That's not what I've meant.
After testing UKP ver 1.0 in June, I got in touch with kaczart and we got to idea of making ver. 2.0 with English language, imperial units (mpg, mph, etc.) and for our cars also wideband afr and vacuum/boost map reading. So most of new changes are done after mine request.
That resulted in change of display area etc. so some sort of hardware had to change along software. Whilst visit to PL I got beta version of 2.0 dedicated for our cars in UK. Had no time to fully test one, but soon with Paul we gonna check all features and give feedback to manufacturer, once we get stable version then it will be for sale.
Nope, no exclusiveness, just testing. There were 2 examples of beta UKP but so far I burnt one doing some testing in hurry. /wall

[adaxo]

Ok, this clarify things a bit/thankyou, by exclusiveness I meant some sort of "special" soft for our cars :idea2:(logo and mentioned above wideband and boost reading specify to vr4s), any way, what about GB?? is very itching me to order that asap but if we can negotiate better price I will be happy to wait a bit.

Now, go out and start testing /bat/lol/lol

[Davezj]

these little gadgets look quite nice and for $90 (i presume USD) hope Ver 2.0 comes out at about the same price.

i would be iterested in one of these.

[swinks]

C'mmon, I'm just back to UK (arrived at 8:30 am), done 5600 miles. Bit knackered.
Anyway, gonna start new thread.

[Davezj]

hope you had a great time back over in Polska (i think).

you have done a lot of work on your car since you have been away, now you need a break from those tireing holidays.
did you do any work on the engine or was it all cosmetic and gadgety.

take a break have a KitKat or two or three oh and a cup of tea.

[swinks]

Engine - just gaskets etc. No major work. Just did full polyurethane to suspension. Well, forgot to use in few places silicone grease on bushings and now my vr4 squeeks like old school wagon.
Anyway nearly killed my engine and tubbys acting mad in Swiss and Austrian Alps passes :)

[lateshow]

The guy who sold this said they already have the 2.0 and he will send that, interesting :)

[swinks]

Yes, that is uprated hardware and new display setup, few improvements for n/a cars and lpg cars, language and imperial units. Owners of vr4's should wait for "2.0.1" version with tested and proved afr and vacuum/boost features.

[lateshow]

I've got mail, apparently. :)

[phosty]

Well, PLX devices have refused to assist in modifying the SM-AFR circuitboard so I can adjust the Narrowband switchpoint:

http://www.plxdevices.com/forum/viewtopic.php?f=1&t=5392

So, Taylor/Paul could you advise on the best way to read the 0-5v WBO2 signal and convert to NB with adjustable switching via a PIC like you have both done? I had a look at some Arduino boards and I think the simplest would be something like the Arduino Uno for £22:

http://www.13cm.co.uk/shop/arduino/arduino-uno/prod_61.html

I was wondering if it would be OK to run this off the car power directly (~14v) as they seem to suggest voltages over 12v could overheat the onboard voltage regulator.

I'm not to bothered having the switchpoint adustable via a switch or dial - via software upload would be fine at first.

Or would you be open to sharing your code so I could just buy the same hardware?

[paulg23]

Hi Phil. Mine doesn't use the 0 -5v from the WBO2 controller, it uses the serial data stream and picks out the relevant bytes. I'll have a think about the easiest way to do what you want.

[paulg23]

A thought... originally with my set up I used a DAC to generate the NBsim output and used a lookup table to replicate the NBsim curve as suggested on the Tech Edge website. Although this worked fine I then removed the lookup table and simply set the DAC to 0v if the measured AFR was 14.7:1 or greater and to 1v if it is less than 14.7:1. This also seems to work fine.

Any comments on using this method?

[scott.mohekey]

A thought... originally with my set up I used a DAC to generate the NBsim output and used a lookup table to replicate the NBsim curve as suggested on the Tech Edge website. Although this worked fine I then removed the lookup table and simply set the DAC to 0v if the measured AFR was 14.7:1 or greater and to 1v if it is less than 14.7:1. This also seems to work fine.

Any comments on using this method?

I'm pretty sure this is exactly what Taylor does.

[phosty]

That's exactly what I was thinking of doing at a high level - but which DAC / PIC would you suggest? I also found the cheapo PICAXE units but the only one which seems to have a DAC is the 18M2:

http://en.wikipedia.org/wiki/PICAXE#Analogue_outputs

They cost an exorbitant £2 (http://www.picaxe.com/Hardware/PICAXE-Chips/PICAXE-18M2-microcontroller/) and also have a BASIC programming IDE. Obviously need a few other bits too. Just looking for the simplest (i.e. laziest) way of achieving an adjustable NBsim.

[paulg23]

- but which DAC / PIC would you suggest?

You dont actually need a DAC if you want to do it this way. Just use a digital output with a couple of resistors to limit the output voltage to 1v (ish).

[paulg23]

Phil - the prototype unit. Orange and black are power, green is wideband in (0 - 5v) and white is NBsim out.

48266

The pot' adjusts the NBsim point.

[Beastlee]

Ok, I'm confused. Was checking mine out again yesterday and today as I had to do the 20 mile run to Elmpt and back. LC-1 is re-calibrated again and reads fine (15.2) at idle as well as going to 22 AFR when the injectors are off. On part throttle it stays between 14.5 and 15.5 and on WOT it seems to stay at 13-14 AFR, dropping to 10AFR once I let off the accelerator, cold start idle starts in the low 12s. Car runs fine as far as I can tell and continues to embarass the German Marques that choose to play but never seeing less than 10AFR just doesn't seem right to me. Any idea what I should be checking? Will it be dangerous to run it like this?
I need to test with the sensor we got for Heidi's RVR and see if the reading is different.

[german_VR4]

Hi,

i run my Legnum with 15.7:1 up to 0,5bar boost (daily driving mod). no problems until now (around 12.000km), also at the german autobahn with permanent speed around 170km/h.

for security i changed spark plugs to BKR8EIX.

more here:
http://tarmac-gravel-snow.de/index.php/legnum-vr4/51

greetings

[foxdie]

Just an amendment to running at 15.2 AFR, I did a journey on Saturday that normally requires me to fill up for the return leg, however I got from Birmingham -> Manchester -> Huddersfield and back again with a quarter of a tank to spare, a noticeable improvement :)

[psbarham]

mine is running high 15's low 16's at cruise, this is giving an average mpg on short local runs of 27.

[darth_grantius]

So how would you go about doing this on a ST-R N/A V6?

[paulg23]

So how would you go about doing this on a ST-R N/A V6?

To start with you need to have a wideband o2 sensor and controller installed. This is applicable to turbo and non turbo petrol engines.

[Wodjno]

Just to add! Not all wideband sensor/controllers can simulate narrowband and alter cruise fuelling. Ensure that you get the correct 1 if going down this route /yes

[paulg23]

If you have a wideband controller with 0 - 5V output I can make you a unit like I made Phil (PHOSTY) that will give an adjustable narrowband output.

[phosty]

I'm happy to report that Paul's gadget works a treat! Yesterday I passed my MOT finally :D

49176

I had set the closed loop switchpoint to 1.03 lambda (AFR 15.1) which is the upper limit for the MOT to give me the best chance at passing the CO limit (0.3%). Now that I have a road legal car I'll adjust the switchpoint upwards and see how the fuel consumption fares.

I did notice that the closed loop switchover seems to occur a lot faster with Paul's gadget compared to the PLX NBsim output - maybe the gradient is much steeper (or vertical?). Seems to work fine anyway.

Cheers Paul!!

[Nutter_John]

Great result Phil , must admit Pauls bit of kit is very nice

[Eurospec]

Sorry for not reading the whole thread- but i saw someone here asked what the lean limit should be.

To answer that, you need to appreciate the afr window in which the engine will run is massive. What you will find however is that as you reduce the amount of fuel, torque will remain static to a point (for a given engine load and ign timing). However, if you continue to lean the engiine out, it will come to a point where torque begins to drop off. At some time after this point the engine will begin to lean missfire, but by this time torque will be drastically reduced.

There is little point in leaning out beyond whatever afr netted you 95% of torque at normal cruise afrs because the torque will drop off quickly. Since it does that, you would need to compensate by using more engine load (Mass of air) and hence mass of fuel in order to net the same level of torque.

So what i am saying is that since afr simply relates the mass of air to the mass of fuel as a ratio, it does not tell you anything about the actual mass of fuel being used to net a certain amount of torque. So if you just lean it out, it wont necesarily use less fuel, since in order to keep moving along at the same rate you will need more engine load, and even at 17:1 if you have gone from 50 kpa to 100kpa you will have still doubled the mass of fuel being used.

Does that make any sense?!

Cheers,

Ben.

[Nick Mann]

Yes! Absolute sense.

So now we need you to stick a VR4 on the dyno and tell us at what AFR the torque figure drops off the cliff.... ;)

[Eurospec]

Yeah, easy peasy lemon squeezy- could do it with anything from an afc controller to a standalone just to find out. In a gto its in the low 15's! Those things love fuel.

In our nissan trainer (200sx) its about 16.5 or 17. That puppy will continue to run all the way to like 22 before it lean misses!

Cheers,

Ben.

[lateshow]

Yes! Absolute sense.

So now we need you to stick a VR4 on the dyno and tell us at what AFR the torque figure drops off the cliff.... ;)


Yes someone should ABSOLUTELY DO THIS!

[Nick Mann]

Ben, if you moved to the Midlands I'd pop over! You are based too damned far south though! /pan

[foxdie]

Ben, if you moved to the Midlands I'd pop over! You are based too damned far south though! /pan

I second this statement, Atik and myself have often said that with our "upcoming lottery win" that we'd pay to move Eurospec to the West Midlands :D

[Eurospec]

Lol, oi! Its me thats gonna win the lottery, and if i do, i'll buy one, do it and tell you the answer!

Cheers,

Ben.

[paulg23]

I did notice that the closed loop switchover seems to occur a lot faster with Paul's gadget compared to the PLX NBsim output - maybe the gradient is much steeper (or vertical?).

Phil - the gradient is vertical!! Thats how I run mine. No problems either.

Glad it did the trick for the MOT.

[lateshow]

Now after trying leaning out i can say that yes it helps a bit but only something like 0.1-0.2l/100km. And the effect is in slow speeds. When youre getting to 100km/h the resistance becomes so big that driving with lean mixture does seem to actually make it worse. I think mine can go uphill better with 14.7 when doing 2500rpm. Leaning + more advance helps much in the 1500-2000 area. Like cruising 20-40 mph...... But no luck after 60mph.

[Shtiv]

I'd tend to agree with that, I got a little better economy at 15.2-15.5 at really light loads but it was bugger all benefit - 0.3-0.4L/100 at best, in the end I just set it back to stoich closed loop, one day I'll play around with it on the dyno but I have about 200 other things i'll be doing first.

[Kenneth]

That shouldn't be a surprise to anyone, seeing as I am assuming people do understand why these numbers are used rather than just doing stuff because other people do it...

~15.2:1 AFR was a figure that was posted on the Innovate forums from someone who did extensive testing and found that 15.2 provided the highest exhaust gas temperature. This means that you are getting the best efficiency (energy output for fuel used) in fuel use.

In very low load situations, you might not need the full energy output, in which case you will get a small increase in economy from using a leaner AFR up to the point in which you require a little more throttle to drive the car at a constant speed.

[Nick Mann]

Whilst I see the logic in what you have just said, Ken, it doesn't explain what was being tried (and to some extent succeeded) with the GDI.

[Kenneth]

That is a different kettle of fish Nick.

It uses EGR to effectively increase compression ratio (which was much higher to begin with) so that it can extract more efficiency from what it does burn. Because of that, at low load you can get enough power from combustion to propel the vehicle. I am sure it uses other technologies to help, but I believe that the static CR and EGR are the main ones with regards to being able to extract enough energy to propel the vehicle. I do recall there being other issue to do with emissions etc, but that isn't really in scope here.

And that being said, a poorly running GDI can use a LOT of fuel.
Was it you who pointed me to Club VR-4 from the GDI fuel complaint thread on some other forum? I was getting not a lot more in the way of MPG from a 1.8 GDI than what a VR-4 can give... So I got a VR-4 :P

[Nick Mann]

Ah. Okay. I didn't realise there was that much to it...

It might have been me - some random american based forum about 7 years ago when these forums kept having outages? I seem to remember suggesting these forums to a couple of people at the time.

[Shtiv]

That shouldn't be a surprise to anyone

Well youd think.... I dunno, we drop the amount of fuel by 3%and people seem to think theyll get a 10% gain, thats one hell of an efficiency change...

[lateshow]

I have a late model Gdi, it uses lean mixture only in light loads, eg driving under 50mph. I've blocked the EGR, it only fills intake with ****e.

On vr4 I used to drive so that when load got to 70 i was getting 14.7 (this was only done with MAF-control) and load 20-60 was about 15.4 @ 2000rpm and 15.1 @ 2500rpm. Since ive got nothing to hide I can get a shot of the maps :) I think it should be run stoich already at load 50. Going downhill gave me better economy with lean mixture. But I'd focus more on getting the best advance possible. I think about 30 is right on low loads @ 2000rpm. I tried to give it more and it started to act lazy. At 1500rpm it is ok to add +5 to stock. But 2500rpm is a mystery. I've tried 35, cant really say. But thats about it you can do. Next stage is ATF thermostat :)

[lateshow]

5026950270


As I promissed, here's my mods. As you can see I've altered the injector scaling a bit. Using 361 I get more accurate AFR, maybe this isnt the right way to do this, propably i would be more right to alter MAF settings. And what i've also done is zeroying out every value in open loop load so that it wont go to closed loop. With these settings mine goes pretty lean when nearly off throttle like downhill situations it can run from 16-17 and still goes smoothly. 80km/h steady straight road, no up or downhills gives me 15.2-15.4. Same situation but 100km/h gives me 15.1. And when doing 1000-2000rpm in light throttle i think this map is at its best. I think the car doesnt respond as quickly as it does in closed loop. When I go uphill, the AFR goes to 14.6-14.7.

And from the pictures you can see what ive done with ignition. Generally +5 but not in all spots. Somebody said that i could do with more but atleast my car starts to feel lazy. I think these are no big secrets. If anybody has better ideas, feel free to say out loud.

[Davezj]

How can you tell if you are in lean cruise situation.

I have posted this on another thread but this where it should really go.


Have any of you noticed when the lean cruise point kicks in. In my car it pushes the AFR to 16 ish depending on actual speed.
But it is such a small window to activate the lean cruise it is not worth trying to maintain.
Basically if you are doing 80 and the boost is 0.0 bar + or - 0.1 bar. The AFR is 16 up from 14.7 but outside this range normal AFR apply.
But if doing 70 and the boost is 0.0bar then 15.6 ish AFR but either side of 0.0 bar and normal AFR figures return.

I believe that because the boost Is 0.0bar the fuel control will be in closed loop, so I can only assume that it is some sort of lean cruise point.

This is not much use and I don't see why the lean cruise range does not go back into the vacuum region, as that is effectively a minimal load area.

Has anyone else noticed the AFR jumping up for motorway cruising.


With a bit of work I am sure this lean cruise region could be expanded.

[wintertidenz]

It seems to be around 2200-2550 RPM according to the log I put up here a while back. That was about an hour of 100-110kph speeds (60-70ish MPH).

The car was sitting around 14.4-15.0 and cycling slightly around that number - TPS was around 20-30%. My boost gauge sits at 10 inHg (about 5 psi vacuum?) during cruise - sometimes down to 15ish. I usually use the boost gauge as an indicator which helps me keep in lean cruise.

If you put your foot down a bit harder the AFR drops a fair bit to about 12.

[Wodjno]

How can you tell if you are in lean cruise situation.

I have posted this on another thread but this where it should really go.


Have any of you noticed when the lean cruise point kicks in. In my car it pushes the AFR to 16 ish depending on actual speed.
But it is such a small window to activate the lean cruise it is not worth trying to maintain.
Basically if you are doing 80 and the boost is 0.0 bar + or - 0.1 bar. The AFR is 16 up from 14.7 but outside this range normal AFR apply.
But if doing 70 and the boost is 0.0bar then 15.6 ish AFR but either side of 0.0 bar and normal AFR figures return.

I believe that because the boost Is 0.0bar the fuel control will be in closed loop, so I can only assume that it is some sort of lean cruise point.

This is not much use and I don't see why the lean cruise range does not go back into the vacuum region, as that is effectively a minimal load area.

Has anyone else noticed the AFR jumping up for motorway cruising.


With a bit of work I am sure this lean cruise region could be expanded.

I don't actually think this is a lean cruise, if we are talking about the same thing?
I can get my car to run at 16+AFR, but i can't keep it at a constant speed while at 16+ AFR. While cruising at any speed, if you then press the accellerator very gently(Not sure what percentage) it will start to accelerate, but the AFR will go t 16+. The car keeps accelerating though until it reaches the max speed it can go at that Throttle position and will then drop back the AFR's to stoich. If you then press the throttle pedal again, it will start to accelerate again and the AFR's will again go 16+. etc.
I think this possibly a bad piece of mapping by Mitzy? If it's not and was mean't to be like this, then i'm not sure what the benefits are ?

Wodj

[Davezj]

I don't actually think this is a lean cruise, if we are talking about the same thing?
I can get my car to run at 16+AFR, but i can't keep it at a constant speed while at 16+ AFR. While cruising at any speed, if you then press the accellerator very gently(Not sure what percentage) it will start to accelerate, but the AFR will go t 16+. The car keeps accelerating though until it reaches the max speed it can go at that Throttle position and will then drop back the AFR's to stoich. If you then press the throttle pedal again, it will start to accelerate again and the AFR's will again go 16+. etc.
I think this possibly a bad piece of mapping by Mitzy? If it's not and was mean't to be like this, then i'm not sure what the benefits are ?

Wodj

Yes that is the effect i am talking about,
All done in 5th gear,
I can get it all through the speed range and it occurs at 0.0bar (with a little margin above and below.)
What i have noticed is at 80 the range is 0.0bar ±0.1bar but at 70 it range is a smaller range and at 60 even smaller range if not spot on.
also the AFR you jump to changes depending on speed. 80 AFR jumps to 16+, 70 AFR jumps to about 15.5, 60 AFR jumps to about 15

am i right in thinking this closed loop opereation?

[lateshow]

There is a spot where closed loop goes off (load roughly 90) and rounds 2000-2500. Then it goes lean, and the reason is what i've been trying to talk to you guys all along. The insanely big low fuel trim which means that you have to add extra fuel after lambda has checked where it sits. And then when you go off from the loop you are using only your fuel trim, no lambda correction-> then you're sitting at max 4,68 and it still isnt't enough-> you go lean.

[Davezj]

i have been re reading this thread again and there 3 distinct topics
lean cruse via wideband output manipulation (simulated narrowband switch poiint)
UTCOM trip computer
Leaning out on light loads just above 14.7 AFR motorway cruise.

i want to go back to the first topic and ask a question about lean cruise in closed loop fueling.
when adjusting the wideband output, does it depend on how much torque is made low down in the rpm range as to how far you can push the AFR towards the lean side. as it has been stated by people who know, once you loose more than 5% torque by going towards the leaner AFR, you will need to put more fuel in to get the same speed out due to the loss of torque.
so if you had adjustable cam gears to setup for more low down torgue at the expense of higher rpm torque then could you push the AFR leaner and gain more MPG, or is it just not worth the effort as the neturn will be minimal.
it has been stated the the gains in economy by pushing the afr lean is only 0.2-0.4L/100km which is not a lot. if you could go leaner how much more could you get?

[TAR]

I'm really glad you bumped this thread as it sounds very much like the 'issue' I have been chasing in my thread. Maybe what I'm seeing is just the way the car works. Unfortunately I'm not very good with this technical stuff so I cant change any settings.

:happy:

[Davezj]

i aam hoping someone in the know will get on board and let us know what the possibilities are.

[swinks]

so if you had adjustable cam gears to setup for more low down torgue at the expense of higher rpm torque then could you push the AFR leaner and gain more MPG...
I don't think you understand purpose of adjustable cam verniers and setting overlap to cams. ;)
In simply other words: not related!

[Davezj]

i was under the impression that you can change the overlap and move the point at whivh the torque comes in the rev range. i assumed that most people would be wanting to move the torque up the rev range and not down.
if you would like to do a very simple description of came gear timing or a link that would be great.

or are you saying changing the cam timing with the pullies does not affect the the point at which torque comes in the Rev range.
am i confusing cam timing with cam profiling eg the cam regrinds with higher lift and profiled lobes.

[swinks]

Davezj, I try to use as simple as possible examples to avoid confusion. In reality it's much more complicated. :)
If... you advance timing (in most cases you dial cams little retard on intake side and more advance on exhaust, most common in 4G63T are 1/-1 or 0/2), our timing rotor blade is attached to exhaust cam, hence you will advance timing, in many cases that require some correction in timing tables to avoid "big bang" and... what next thing you should do to prevent bang? Dumping even more fuel in some areas by mods to fueling tables.

Play with aggressive cams, overlap it's a play with timing as well. Yes, result is modified torque and power curve but not as a result of leaning mixture! In some cases quite opposite.

[Davezj]

the point i was trying to make was in conjunction with the modification of the simulated narrow band output to to lean off the closed loop part of the ECU function to gain more economy.
it was also mentioned that if you lean out this closed loop operation then you loose torque, so leaning out past a certain point would gain nothing, as you would have to more fuel with the accelerator to get back to the point that you were trying to lean out.
so the point i was try to make (not very well by the sounds of it, lol) was could gain some more low down turque with the use of cam gears to compensate for the loss of torque while leaning out the closed loop operation.

i know this is not the normal way of doing things as most people are after more power/torque at the expense of fuel consumption and not the other way round as i was asking.
but by the response you gave i presume not.
i know if want a economic ride the VR4 is not the one to have. but there is harm in being a little more economic.

[fassi1]

Lambda different than 1 may cause MOT emission test failure.
There is other load areas where economy can be improved where VR4 is overfuelled.

[Davezj]

not quite sure what you mean?
isn't lambda 1V or 0V swtich about the 14.7 point. do you mean AFR change by 1.

i am only talking about closed loop.
i thought the fuel and timing maps that can be changed in the ecu where only for open loop operation.
or are they for both modes of operation.

just out of interest, how would making the AFR 16 instead of 14.7 make the emmision worse. i don't know i am just after info to try and understand this sort of stuff more.

[fassi1]

AFR is only a factor of lambda (air fuel ratio parameter). lamnbda = 1 is at stechiometry which means AFR = 14.7 for petrol, 15.5 = for LPG, 14.6 = diesel.
lambda = 1 means best emission and that's the reason why target in closed loop is 14.7 cause manufaxturers have to look after environment.
lambda > 1 means AFR > 14.7 means better economy but worse emission and less power
lambda < 1 means AFR < 14.7 means more power but worse emission and worse economy.
Target for emission test is lambda = 1 with some little variance.

[Davezj]

Thanks chris, that is really nice explanaion and makes sense, so 14.7 AFR is the fullest/cleanest burn, so if all thing are burn perfectly the emssions should be zero.

but nothing in life is ever 100% efficient.

[taylor]

The loss of torque at this load by changing the solely the afr is negligible.

You can push you lean cruise to wherever you feel comfortable, the less fuel you put in the greater the chance of detonation, the hotter your block will get and a higher rate of wear on the motor.

There are other issues to take into account such as whether or not the vehicle has a catalytic converter fitted, and local emission laws/requirements.

Ive personally pushed my own 6a13tt to about 1.1 Lambda at cruise. The increased fuel economy and engine temperature were both noticeable.

All motors will react differently to fueling changes at idle/cruise, and as stated there are defiantly areas in the factory tune that can be improved upon.

[Davezj]

taylor what happened to engine temp, do you know what it went up to and from what, i will need to know my cooling system can combat this before i adjust it.

or i can try it and see what happens when i run it, i do have a temp gauge on the top hose of the radiator to measure the engine exit temp correctly. are you talking a 10C rise or les or more.
the reason i am asking is i have a over heating issue at the moment due to my fans only running at low spin speed they never go to high spin speed, i can sort this quite easily but an expected value of temp rise would be really useful.
you have got me quite excited by you comments, i have done a convertion and 1.1 lambda is about 16 AFR for petrol. so this is interesting.

[Davezj]

just thought i would do it properlythis is a lookup table, it is a full list of Lambda vs E85 AFR vs Petrol AFR,
i have it as an Excel spreadsheet or you can have it as a comma or tab separated variable text file.

or you can take the fist 3 or 4 valuse put it into excel then use excel to expand the columns, i have checked and the expanded columns will create the following data.

Lambda E85 AFR Gas AFR
0.500 4.880 7.350
0.510 4.978 7.497
0.520 5.075 7.644
0.530 5.173 7.791
0.540 5.271 7.938
0.550 5.368 8.085
0.560 5.466 8.232
0.570 5.563 8.379
0.580 5.661 8.526
0.590 5.759 8.673
0.600 5.856 8.820
0.610 5.954 8.967
0.620 6.051 9.114
0.630 6.149 9.261
0.640 6.247 9.408
0.650 6.344 9.555
0.660 6.442 9.702
0.670 6.539 9.849
0.680 6.637 9.996
0.690 6.735 10.143
0.700 6.832 10.290
0.710 6.930 10.437
0.720 7.027 10.584
0.730 7.125 10.731
0.740 7.223 10.878
0.750 7.320 11.025
0.760 7.418 11.172
0.770 7.515 11.319
0.780 7.613 11.466
0.790 7.711 11.613
0.800 7.808 11.760
0.810 7.906 11.907
0.820 8.003 12.054
0.830 8.101 12.201
0.840 8.199 12.348
0.850 8.296 12.495
0.860 8.394 12.642
0.870 8.491 12.789
0.880 8.589 12.936
0.890 8.687 13.083
0.900 8.784 13.230
0.910 8.882 13.377
0.920 8.979 13.524
0.930 9.077 13.671
0.940 9.175 13.818
0.950 9.272 13.965
0.960 9.370 14.112
0.970 9.467 14.259
0.980 9.565 14.406
0.990 9.663 14.553
1.000 9.760 14.700
1.010 9.858 14.847
1.020 9.955 14.994
1.030 10.053 15.141
1.040 10.151 15.288
1.050 10.248 15.435
1.060 10.346 15.582
1.070 10.443 15.729
1.080 10.541 15.876
1.090 10.639 16.023
1.100 10.736 16.170
1.110 10.834 16.317
1.120 10.931 16.464
1.130 11.029 16.611
1.140 11.127 16.758
1.150 11.224 16.905
1.160 11.322 17.052
1.170 11.419 17.199
1.180 11.517 17.346
1.190 11.615 17.493
1.200 11.712 17.640
1.210 11.810 17.787
1.220 11.907 17.934
1.230 12.005 18.081
1.240 12.103 18.228
1.250 12.200 18.375
1.260 12.298 18.522
1.270 12.395 18.669
1.280 12.493 18.816
1.290 12.591 18.963
1.300 12.688 19.110
1.310 12.786 19.257
1.320 12.883 19.404
1.330 12.981 19.551
1.340 13.079 19.698
1.350 13.176 19.845
1.360 13.274 19.992
1.370 13.371 20.139
1.380 13.469 20.286
1.390 13.567 20.433
1.400 13.664 20.580
1.410 13.762 20.727
1.420 13.859 20.874
1.430 13.957 21.021
1.440 14.055 21.168
1.450 14.152 21.315
1.460 14.250 21.462
1.470 14.347 21.609
1.480 14.445 21.756
1.490 14.543 21.903
1.500 14.640 22.050

[fassi1]

If I was you Dave I would log the data on long run (engine temp, knock sum and others) running stock maps or whatever you running now before your adjustments
and then do your adjustments and log the same data again and compare them.
Other areas can be trimed is mid and high load especially running stock boost.
There is no need to run AFR 10s or 9s.
Good remap with logging AFR and knock sum can improve economy too.
Below stock high octane map.

[Davezj]

cheer chris, again great info.
rep coming your way

[fassi1]

Thanks Dave.
I'm after EGT kit at the moment .
Has somebody ever tested EGT at different AFRs and boosts?

[Davezj]

Think you might need a new thread to discus EGT as I doubt any will find you question buried in a lean cruise thread.

[Davezj]

If I was you Dave I would log the data on long run (engine temp, knock sum and others) running stock maps or whatever you running now before your adjustments
and then do your adjustments and log the same data again and compare them.
Other areas can be trimed is mid and high load especially running stock boost.
There is no need to run AFR 10s or 9s.
Good remap with logging AFR and knock sum can improve economy too.
Below stock high octane map.

Is there a guide to roughly know what to set AFR to against a given load.
I presume it is a case of set it rich then lean it out until you get knock, then dial it back.
Which is why dyno tuning is so great.

[swinks]

Thanks Dave.
I'm after EGT kit at the moment .
Has somebody ever tested EGT at different AFRs and boosts?
Boost 0.9 bar
- 5500 rpm, afr 10.8:1, egt front bank 840C
- 5500 rpm, afr 11.4:1, egt 910C
- 5500 rpm, afr 11.2:1, egt 890C

[fassi1]

As you look at stock map the lowest AFR is where the max power is achieved.
It would be great if you could log AFR and knock sum and see what you getting with stock map.
After that lean out all the 10s and 9s to 11s exactly the same as Kenneth's map.
Log AFR and knock sum again and see what you get as its never exactly the same as target map.
I would keep the max power areas no less than 11 and other high load areas 11.5s making sure that knock sum is safe.
Max power is achieved when AFR around 13, everything less than 13 is to avoid knocking and lower the temp.

[Davezj]

cheers chris.

[swinks]

Max power is achieved when AFR around 13, everything less than 13 is to avoid knocking and lower the temp.
It's 12.5:1 in forced induction and 12.8:1 in n/a vehicles to be precise.

[fassi1]

http://www.volvoclub.org.uk/air-fuel-ratios.shtml
I think that's rather truthful info written by experianced professional.
I experianced that having Volvo 2.4LPT which as standard runs AFR 14.5-14.0, is it suiside?
Confirmed by HLM Bromsgrove ( Hamish - very nice guy with nearly 30 years of experiance in tunning Volvos )
AFR 14.5-14.0 perfectly correct for this engine.
Stock Audi 2.7bit having stock EGT runs AFR 13.

[swinks]

http://www.volvoclub.org.uk/air-fuel-ratios.shtml
I think that's rather truthful info written by experianced professional.


Let me quote:
These three facts collectively imply that there is power to be gained by richening the mixture beyond lambda 0.9 and then utilizing part of the increased knock limit to advance spark and in this way produce more power.
That been said here and there on many occasions by valmes, Gowf, Ben, Kenneth or recently by me. Seems, not first time ignored.

Chris, Dave... issue with 6A13TT engine is rapid increase of knock and egt at high load. Where in other engines you have big marign for play with advanced tiiming, leaning mixture etc, here you are lucky to get away with few knocks instead detonation.
Instead of waste time here, please book yourself for few days dyno and do runs with different settings to mixture, boost and timing. Don't forget to monitor egt as well :)
Maybe there is something in engine tune that forum community here overlooked and haven't noticed for 8 years or so.

[fassi1]

Quote:
Fuel Enrichment Effect On High Load Operating PointsThe lambda for maximum power (actually imep - indicated mean effective pressure) given a fix ignition angle and fix engine speed will vary slightly from application to application but occurs in the range lambda 1 to slightly rich of 0.9 (Air Fuel Ratio - AFR 14.7 to 13.2). Normally imep peaks slightly lean of lambda 0.9. Above Lambda = 1 (AFR 14.7) imep will decay quickly as lambda increases, below 0.9 it will decay slightly as lambda decreases. To make a sound choice of which lambda to run one has to consider thermal limits of the combustion chamber- and exhaust components, as well as knock limits. If the operating point is not critical with respect to knock,or with respect to excessive thermal stress on exposed components the lambda to run is close to 0.9 as mentioned before. This is because at this lambda the maximum number of oxygen molecules will take part in combustion. Adding more fuel than this portion at the given conditions will not give more power because there are no more oxygen molecules available. Any additional fuel added will flow through the engine unburned, and as it then stays a liquid it will have a cooling effect on the combustion process.

And that is exactly what I said before. Max power with AFR around 13, extra added fuel is to avoid thermal stress and knocking.
I don't think that it's something different to what club community noticed through sll this years.
All the data can be monitored and setting tested without rolling road,

[Davezj]

this is all interesting info guys, but the way i read the info you both give is from the same book.

you can try and lean out or richering the maps but you have to do whilst monitoring all the perameters required, and obay the gods of knock or fear there rath. sbut you have slightly different limit points you think you can push it to.
i am sure everybodies engines are different due to mods applied, so everbody will get different results. but the theory is the same, i will be very careful, and obay those gods of knock.
i suppose it depend also on whet type of margin of error/safety you want to guild into your mapping.

it will be interesting to see what pans out when for me when i start the process.

[fassi1]

I don't disagree with Tomasz. I've been trying to explain to find balance between overfueling stock maps
and max power with good economy. I think there is a lot more satisfaction from achieving good result by doing it by yourself
than paying somebody to do the job that's why there is always gonna be questions and debate.
Not many people want to share knowladge, how to achieve good result or even setups.

[Davezj]

i am looking forward to having a go.

[lateshow]

By the way chaps, when you go the E85 way, knocking won't be an issue. But still the engine will suffer at high loads and high rpms from the fact that turbos are too small. :)

[Davezj]

it is nice to know we a missing out, LOL.
going off to check if E85 fuel is available on the UK, just out of interest.
it seems to be few and far between at some morrisons supermarkets. about 20 in the country, unless the info i looked at was old data.

[fassi1]

Running 12-11.5 on lpg and 0.9bar knocking is not an issue too.

[Davezj]

we do have that option of LPG in the UK. but have to convert the car to run on LPG where as the E85 runs straight in the normal petrol tank.
Personally i intend going down the LPG route at some point. so all is good.

[taylor]

Sure there are gains to be had adjusting afr. but unless it is really out on the stock mapping, the gains are next to nothing compared what can be gained to adjusting you ignition timing.

There are many different situations where aft under high load high boost can be increased or decreased in relation to the ignition timing. Its not something I am going to explain over the internet, its something that's gained with experience of tuning high end aftermarket Engine management systems and highly strung race engines.

Leaning the afr out at cruise will cause the gas to burn hotter, increasing egt temps, increased block temps in return a higher strain on the cooling system

When I was younger and had far less of an idea to what I was doing a custom narrowband simulator off the 0-5v on the wideband. as stated it ran around the 16 mark. The under bonnet temps were defiantly hotter, the cooling system had no issues although I was running a 1.1 bar radiator cap. I then did a 1000km drive and I cant remeber the figures but they were pretty good. You need to do your own testing and determine your own safe levels.

[scott.mohekey]

How's your Galant going then Taylor?? ;)

[lateshow]

But if one adjusts the fuelling so that AFRs dip right down to 11 the car feels lazy. BUT if one adjusts them so that at first it is at 14 sharp, then at 2500 about 13 or 12.5 and 12 around the max torque area richening out to 11.5 at max one gets the best "feel". I have noticed that the car still knocks on gasoline if you make the mixture too rich :)

[Z-Kev]

if you really want to get rid of knock take a look at toluene, 5 litres to a 60 litre tank should do it though that is £17 and then this stuff is chaper and got a good 2.8 ron increase in a test I saw

http://www.racingbeateurope.com/b-fb-fs04-nulon-pro-strength-octane-booster---newb-1442-p.asp

[Davezj]

thanks for the info all, i will take your advice, you are saying the same thing really, i will do my homework and take it easy, small adjustments only on the fuel and timing maps and maybe lean out the Narrowband simulated signal slightly.
but testing testing testing all the way, to ensure my engine remains in one piece.

[taylor]

But if one adjusts the fuelling so that AFRs dip right down to 11 the car feels lazy. BUT if one adjusts them so that at first it is at 14 sharp, then at 2500 about 13 or 12.5 and 12 around the max torque area richening out to 11.5 at max one gets the best "feel". I have noticed that the car still knocks on gasoline if you make the mixture too rich :)

Why are you enriching the fuel mixture at that point? and to 11 afr? This will of course hinder the tune so sluggish performance is not at all surprising.


if you really want to get rid of knock take a look at toluene, 5 litres to a 60 litre tank should do it though that is £17 and then this stuff is chaper and got a good 2.8 ron increase in a test I saw

http://www.racingbeateurope.com/b-fb-fs04-nulon-pro-strength-octane-booster---newb-1442-p.asp

No! Additives are bad news. I dont care what your sisters husbands uncles dogtrainers cousin told you, they pretty much just mask symptoms of knock. The only additive to gasoline that should enter your fuel tank is ethanol. This opens another kettle of worms, and obviously must be tuned for.

[Z-Kev]

Why are you enriching the fuel mixture at that point? and to 11 afr? This will of course hinder the tune so sluggish performance is not at all surprising.



No! Additives are bad news. I dont care what your sisters husbands uncles dogtrainers cousin told you, they pretty much just mask symptoms of knock. The only additive to gasoline that should enter your fuel tank is ethanol. This opens another kettle of worms, and obviously must be tuned for.

The benefits of toluene are well known in the automotive racing world, anything with extra kerosene masks knock , true ron boosters do not, in fact toluene was used in formula one to allow the turbocharged cars to run ridiculous amounts of boost with no knock, way beyond what the engine design and control would normally allow,in fact toluene is a ingredient of petrol anyway, take a look here at page 7 http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1194947317038, most boosters do mask knock but not all.There are engine tuners in the saab world with full tests carried out on toluene and its affects on the ignition maps vs boost control.

[lateshow]

Im just explaining what happens if you rescale the injectors so that you get a moving Low fuel trim ( as stock it sits tightly at 4.68 and all around you get leaner mixture than in the AFR maps) By rescaling I mean making the scaling value smaller so that engine gets more fuel and LTFT doesnt have to be maxxed out.

[fassi1]

Im just explaining what happens if you rescale the injectors so that you get a moving Low fuel trim ( as stock it sits tightly at 4.68 and all around you get leaner mixture than in the AFR maps) By rescaling I mean making the scaling value smaller so that engine gets more fuel and LTFT doesnt have to be maxxed out.
That's very truth.
The hotter it gets the higher the STFT so more likely to suffer from lean idle AFR > 14.7
Moving LTFT closer to 0% gives AFR in closed loop closer to stock maps.

[lateshow]

That's very truth.
The hotter it gets the higher the STFT so more likely to suffer from lean idle AFR > 14.7
Moving LTFT closer to 0% gives AFR in closed loop closer to stock maps.
Yes this is true, but when you rescale the injectors the area where the boost builds up doesnt seem as good as it is with standard scaling. Car feels much lazier and doesn't respond. I am using approximetely 88% of the original scaling value and i'm gettin about 1-2 % STFT for gasoline, I have also retuned the AFR map for gasoline so that it has much leaner values in the low rpm at big loads so it doesn't go right ahead to 11.5 AFR. Acceleration enrichment has an effect too here. This means that the AFR's dip easily to rich area.

[fassi1]

That's right, I've noticed the same situation.
Tested few different values for injector scaling and looks like 351 is the best one, keeps LTFT close to 0%
The thing is that after rescaling injectors open loop area has been offseted by the difference between LTFT before rescaling and LTFT after rescaling,
when closed loop remains unchanged with target 14.7, that's why as soon as ECU switches from closed loop to open loop (boost buildup) there is sudden dip in to AFR 12-11.
I reckon, after rescaling injectors, whole open loop area needs to be adjusted to bring AFR down to max performance values so logging data would be required.

[lateshow]

That's right, I've noticed the same situation.
Tested few different values for injector scaling and looks like 351 is the best one, keeps LTFT close to 0%
The thing is that after rescaling injectors open loop area has been offseted by the difference between LTFT before rescaling and LTFT after rescaling,
when closed loop remains unchanged with target 14.7, that's why as soon as ECU switches from closed loop to open loop (boost buildup) there is sudden dip in to AFR 12-11.
I reckon, after rescaling injectors, whole open loop area needs to be adjusted to bring AFR down to max performance values so logging data would be required.

Yes, this means that you have to much bigger AFR values the places i suggested. But it seems still that it is eager to make a dip and that is because of the acceleration enrichment.

[fassi1]

Yes, this means that you have to much bigger AFR values the places i suggested. But it seems still that it is eager to make a dip and that is because of the acceleration enrichment.
Do you mean table Accel Enrichment TPS Delta Multiplier.

Done few runs on shell V-power with modified high octane AFR map and injector scaling DSM 351 and results were very close to the target with very rare knocking < 3
Pic 1 is target, 2 and 3 logged data

[lateshow]

Good one fassi1!

I think you could still run a bir leaner @ load 100 ( I think one could still run close to 14.7. But if your arse tells you that car feels good then ok! :) I can't log anymore those afrs cause i have the ethanol sensor on 75. :)

[fassi1]

I've done some adjustments after doing this test but due to rather slippery and snowy roads. :thumbsdow they haven't been tested yet.
The other thing is, that some of these logged values include some stupid numbers like 0, 20, 25, 69, so for that reason average value displayed in 3D map is far from truth values.
This sort of result will definitely give better economy than stock map with 10s and 9s.
Still more testing to come.

[lateshow]

Yes, however when thinking about economy, @ that boost level you're still burning a lot of fuel and there's nothing you can do about it. So the actual economy areas are at loads 0-100. Now that you have a perfect scaling, try putting her on open loop. If you have standard airbox you will get within +-0.1 AFR all the time ( i suggest the following: try to reach 15.2 generally and 14.7 when load is 70 -100.) :)

I've seen one vr4 in Finland that has a living LTFT with standard scaling, others have been 4,68. Im using 354 as a base value for 0% ethanol content.

And yes i meant Accel Enrichment TPS Delta Multiplier. :)

[fassi1]

60958Yeah like you said the area above the line to around end of the vacuum can be adjusted to around 14.7 to give better economy,
but below the line, which is closed loop, without cheating ECU playing with narrowband signal, not much can be achieved, cause ECU will do its best
using fuel trims to hit 14.7.
I agree, talking about economy in boost areas sounds a little bit confusing:dizzy2:

[disco-ian]

Lambda different than 1 may cause MOT emission test failure.
There is other load areas where economy can be improved where VR4 is overfuelled.

Not with LPG :-) Emissions tests go back to pre CAT test. lol