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666damned
06-08-2009, 11:54 AM
hi guys............quick question ,just fitted some nice new gauges and ordered a manual boost controller,engine is stock and boost is giving a peak of 8psi.....what can i safely take it to?.....not looking for huge power gains ,but maybe just a tad more than stock.........


dave

Nutter_John
06-08-2009, 12:00 PM
wow a question that has never been asked before !!!

Stevo
06-08-2009, 12:03 PM
well from what iv read and please dont hold me to it,........

ya can have 12 psi but if it spikes higher you get the boost cut rareing its ugly head, i dont have any turbos on mi legnum tho so what i say aint gospel by any means.

hopefully that helps

stephen

Wodjno
06-08-2009, 12:13 PM
wow a question that has never been asked before !!!


Yes it has ! You EVO driving Muppet :p

Don't you know how to use the search button ?

And on topic !
Until fuel cut intervenes /yes


Chers

Wodj :D

666damned
06-08-2009, 12:22 PM
wow a question that has never been asked before !!!

wow....... thanx for that john.................:d ..........:coat

AlanDITD
06-08-2009, 12:28 PM
Woodj - i thought this but have discovered otherwise of late. My car doesnt seem to supply enough fuel at like 14psi. The wideband readings were a touch lean than i would have liked. Plus on the 1/4 the car was running rediculously hot and running slower times.


i.e @11psi i was running 13.6 though great was the boost up and quicker times i was very wrong after 1 run i couldnt get the car back in 13's turned it down a touch and it was 13.6-13.8 all day again.

Not sure how much was heat soak or how much was det and the ECU backing off the timing but there was a deinate performance loss.

possibly a big wapping intercooler may help in my case but i know wont be running anything over 11psi.

Nutter_John
06-08-2009, 12:31 PM
what AFR's are you reading on full chat ?

Sorry Dave but the question has been asked so many times ( but at least you see the funny side )

AlanDITD
06-08-2009, 12:36 PM
what AFR's are you reading on full chat ?

Sorry Dave but the question has been asked so many times ( but at least you see the funny side )

into the mid 13's its not a perm one i have in my car its a dyno one thats been apadated to use on the road.

Even the heat coming out the tailpipe is rediculous on around 14psi. With it turned down its pretty normal.

I need to do some proper logging off the wideband, might pop down tonight and ask to borrow it again.

Nutter_John
06-08-2009, 12:39 PM
I'd be very worried if you are running that lean on standards , i assume you have it stuck in the tail pipe and not in the de-cat area

yes is the car runs lean the it will be running hotter , have you checked you ecu to see if it has been updated ( mines etc ) , and have you tried evoscan to see if your hitting knock at those levels

Wodjno
06-08-2009, 12:42 PM
Alan. i wasz running upto 1.2 bar on standard fuel pump, but never ran lean. Possibly your FPR is weak and not supplying the correct pressure or your pump is failing at those boost pressures..

Cheers

Wodj

AlanDITD
06-08-2009, 12:46 PM
I'd be very worried if you are running that lean on standards , i assume you have it stuck in the tail pipe and not in the de-cat area

yes is the car runs lean the it will be running hotter , have you checked you ecu to see if it has been updated ( mines etc ) , and have you tried evoscan to see if your hitting knock at those levels


I have evo scan mate but i dont have the cable yet. The probe is in the tail pipe so granted the mixture will show slightly leaner anyway as the mixture will be slightly more diluted.

Ill check the ECU tonight although it does look pretty normall compared to the factory one, and ill try do some pulls and logs tonight with the wideband with boost pressure low and high see what AFR's are exactly. Maybe its ok but it did feel slugish as such just didnt really want to rev like it does now. Alot coulod be heat soak. water temp is fine but EGT's although i cant measure them are friggin boiling at 14psi.

AlanDITD
06-08-2009, 12:48 PM
Alan. i wasz running upto 1.2 bar on standard fuel pump, but never ran lean. Possibly your FPR is weak and not supplying the correct pressure or your pump is failing at those boost pressures..

Cheers

Wodj

How hot did the car get? i.e if you cover the tail pipe and feel the heat.

the other thing is the carbon on the tail pipe at 14psi i get next to none another thing i though could be an indication of it running lean.

Subaru ETA
06-08-2009, 01:11 PM
every car is different. my car can run at 16 - 17psi all day with no fuel cut

Wodjno
06-08-2009, 01:21 PM
every car is different. my car can run at 16 - 17psi all day with no fuel cut

Your 1 lucky Dude ! /yes Duuuuude :D

miller
06-08-2009, 01:38 PM
every car is different. my car can run at 16 - 17psi all day with no fuel cut

obviously its here that shows there is a difference between the density of the air in the UK versus NZ. i get fuel cut all day every day at 14psi

as always stated Stock VR4's hit mid 14sec 1/4 mile and always dyno 20bhp higher than our stock!

Got to be!

AlanDITD
06-08-2009, 01:45 PM
obviously its here that shows there is a difference between the density of the air in the UK versus NZ. i get fuel cut all day every day at 14psi

as always stated Stock VR4's hit mid 14sec 1/4 mile and always dyno 20bhp higher than our stock!

Got to be!

But denser air = less boost so for that theory to be right they should fuel cut before us.

vr4-fan
06-08-2009, 03:14 PM
alan , if you want put your car rich and dont cut 15 psi , get out the thermostat . and done ,

AlanDITD
06-08-2009, 03:23 PM
alan , if you want put your car rich and dont cut 15 psi , get out the thermostat . and done ,

Thanks vr4-fan. I think id rather run lower pressures until it could be done safely though :)

666damned
06-08-2009, 05:30 PM
thanx for all the comments guys..................i think....lol.......

Turbo_Steve
06-08-2009, 05:37 PM
alan , if you want put your car rich and dont cut 15 psi , get out the thermostat . and done ,

Whilst this WILL make it run richer, the car will also run massively reduced timing when very cold: removing the thermostat causes the engine to run improperly. Also, as the engine heats up, (i.e. using lots of boost) then the ECU will make it leaner, which will then lea B A N G !!! OH No! My engine blew up.

AlanDITD
06-08-2009, 06:04 PM
Ok quick question, sorry for hijack. If my plugs were gapped incorrectly i.e to wide. Could this cause the egine to be running hot on more boost?

Nick Mann
06-08-2009, 06:09 PM
There is no such thing as a safe boost pressure. "Safe" is down to an individuals interpretation.

1. Safe could mean you have no detrimental effects on your turbos whatsoever.
2. Safe could mean the engine doesn't immediately let go.

In scenario 1, don't turn the boost up at all. In fact, sell the VR4 and buy a V6. This is the thing that not many of us advertise - turning up the boost will at best reduce the life of your turbos. In scenario 2, turn it up until you hit fuel cut and then keep your fingers crossed that the fuelling is still acceptable.

The only "safe" answer is to go to a rolling road, and monitor knock & afr whilst turning the boost up. You'll at least be able to quantify how safe you are being.

Having said all that, the optimistic gambling man on here would go for 1.0 bar of boost as a safe max. The pesimistic gambler would be around 0.8 bar. But both would be gambling to a certain extent without monitoring the health of the engine whilst boost is increased.

Nick Mann
06-08-2009, 06:11 PM
Ok quick question, sorry for hijack. If my plugs were gapped incorrectly i.e to wide. Could this cause the egine to be running hot on more boost?

I'm no expert on this, but a large plug gap and high boost would probably lead to blow out/misfire I think? I'm not sure how this would lead to high temps.

AlanDITD
06-08-2009, 07:05 PM
I'm no expert on this, but a large plug gap and high boost would probably lead to blow out/misfire I think? I'm not sure how this would lead to high temps.

Ok cool wel i just went and pulled all my plugs out with the intention of changing them if knackered but to check the gap. They all seem fine anyway im no expert on plugs but there not bright white and there not black either so looks pretty normall.

666damned
06-08-2009, 07:40 PM
ever get the feeling you wish you had never asked......................lol.......

elnevio
06-08-2009, 08:35 PM
ever get the feeling you wish you had never asked......................lol.......
Yes, I wish you'd never asked... :D:D

Subaru ETA
07-08-2009, 12:16 AM
alan , if you want put your car rich and dont cut 15 psi , get out the thermostat . and done ,

wow! why didnt i think of that! /hammer /JawDroppi

AlanDITD
07-08-2009, 01:18 AM
ever get the feeling you wish you had never asked......................lol.......

Better to know i would say, Its true that every car is differnt. The only sure fire way to be 100% your car is safe is to buy monitoring tool. Wideband, and evo scan would be a good start, before messing.

Everyone is quick to say that you can run untill fuel cut etc etc, but know one knows 100% for sure that its is safe 100% of the time.

Ryan
07-08-2009, 07:55 AM
I'm no expert on this, but a large plug gap and high boost would probably lead to blow out/misfire I think? I'm not sure how this would lead to high temps.

This is precisely what happened to me when running higher boost on standard (1.1mm) gap plugs. An example of what would happen would be say... snap from 4th to 3rd at 100km/h and it would build.... build and then *pop* and car would lose power. To get around this I'd have to snap it and then roll my foot on the throttle

Have since changed to 0.8mm and new ignition leads which does help quite a lot.

elnevio
07-08-2009, 08:33 AM
standard (1.1mm) gap plugs
Regardless of boost levels, 0.8mm is the standard plug gap for the 6A13TT.

1.1mm is however the standard gap for the N/A 6A13.

AlanDITD
08-08-2009, 06:43 PM
Ok some figures from the wideband i used today. On my car at standard (or as near to as possible give mods) boost pressure, car went off the scale rich down into the 9's somewhere.

At 13-14psi where i have left it, the car is 11.3-11.5 on full go. Its prefect 14-15 on partial throttle.

Obv that doest tell us anthing about ign timing which is where i think performance is suffering. About to go try evo scan for the 1st time see if i can get some knock readings.

Ryan
08-08-2009, 09:59 PM
Regardless of boost levels, 0.8mm is the standard plug gap for the 6A13TT.

1.1mm is however the standard gap for the N/A 6A13.

Clearly I am misinformed. :coat

vr4-fan
17-08-2009, 04:57 AM
well , I dont understand HOW he can get 13.6 , with only 11 psi! your car its manual??? my car with 14 psi , only run 14.2 sec stock

Turbo_Steve
17-08-2009, 07:31 AM
Hi VR4-fan:

What are the ambient temps when you run?
What is the air-pressure (e.g. how far above sea level are you?)
How are you launching the car?

Maybe do a search on "Drag strip", "launch" or "Santa pod".

I'd suggest you probably need to start a fresh thread.

And sometimes, more boost is NOT the same as more power.
If you're getting detonation, then the car will be pulling timing.
What condition is your transfer case and diff fluid in?
If ambient temps are high, what intercooling are you running?

If you can get your hands on a CO2 fire extinguisher and you're on the factory cooler, and it's really hot where you are, you may find it helps to freeze the intercooler using your fire extinguisher just before you run.

AlanDITD
17-08-2009, 09:25 AM
well , I dont understand HOW he can get 13.6 , with only 11 psi! your car its manual??? my car with 14 psi , only run 14.2 sec stock

So its not stock then? Maybe i have more mods, maybe you cant drive. Every car is differnt i dont know. Its pointless even comparing. There different strips, differnt fuel and differnt countries.

There is no comparrison. Maybe you have the fastest Vr4 in the country your from??


Dont get so hung up on times, there noice to have but unless you are racing on the same day as another car then theres no comparrison really.

Its mean to be fun, i think you take all of this far to seriously tbh.

vr4-fan
17-08-2009, 04:54 PM
Hi VR4-fan:

What are the ambient temps when you run?
What is the air-pressure (e.g. how far above sea level are you?)
How are you launching the car?

Maybe do a search on "Drag strip", "launch" or "Santa pod".

I'd suggest you probably need to start a fresh thread.

And sometimes, more boost is NOT the same as more power.
If you're getting detonation, then the car will be pulling timing.
What condition is your transfer case and diff fluid in?
If ambient temps are high, what intercooling are you running?

If you can get your hands on a CO2 fire extinguisher and you're on the factory cooler, and it's really hot where you are, you may find it helps to freeze the intercooler using your fire extinguisher just before you run.

88F

28psi air pressure

launching 2200rpm


the problem its the car have detonation i thing the spark its bad , and 1 bar ayc on when I star run ,

thorpe1983
23-08-2009, 11:59 AM
my mates vr4 is running 16psi and is running great

Kelly&Ben
23-08-2009, 07:35 PM
Ok some figures from the wideband i used today. On my car at standard (or as near to as possible give mods) boost pressure, car went off the scale rich down into the 9's somewhere.

At 13-14psi where i have left it, the car is 11.3-11.5 on full go. Its prefect 14-15 on partial throttle.

Obv that doest tell us anthing about ign timing which is where i think performance is suffering. About to go try evo scan for the 1st time see if i can get some knock readings.

my afr's are pretty similar if i remember right from the rolling road and thats at same(ish) boost

Subaru ETA
25-08-2009, 01:55 AM
well , I dont understand HOW he can get 13.6 , with only 11 psi! your car its manual??? my car with 14 psi , only run 14.2 sec stock

everybody knows the only real way to compare is to have the cars, sitting next to each other at the same track. Even then, if you cant drive for **** you are still going to loose even if your car is faster!

Turbo_Steve
25-08-2009, 08:12 PM
VR4-Fan, you haven't mentioned what AFRs you're running?

Nick Mann
25-08-2009, 10:19 PM
my mates vr4 is running 16psi and is running great

Mine has been set at 1.3 bar in the past and was a tad rapid. At the time, I said it was running great too. A year or so later and the turbos were dead though....

Plus the supporting mods helped - custom exhaust turbo back, fuel pump & fpr, ARC intercooler, piggy back ecu etc.

I wouldn't touch that kind of boost level in a standard car without checking wideband and knock. TBH most standard VR4's would be hitting fuel cut well before that anyway.

steelie600
12-09-2009, 06:01 PM
my car hits fuel cut at 15psi, si ve set my boost at a conservative 12 psi, and my afr is almost 14:1 across the board except bleedin cruising at 80-90 where its a crap 9!!!

AlanDITD
12-09-2009, 06:59 PM
Eh. you get 14:1 on boost and 9:1 on cruise? Or did you just type that backwards?

steelie600
12-09-2009, 07:09 PM
no according to my af meter im gettin 13.7:1 at full boost and wot which i dont understand either after reading other posts, ill plug my scanner in and try again gimme 10 mins

steelie600
12-09-2009, 07:26 PM
Right been out again with scanner on and probe up the exhaust

afr at wot is 10.9 cruising 12.6 lambda is 1.06 most of the time except for very high revs when it does drop to 1 but the most alarming thing is the hydrocarbons up at 600 ppm rising to 900ppm at high revs. Which says to me its over fuelling like hell. Ahh well best get savin!!!

And this afr guage is going back to halfords in the mornin

AlanDITD
12-09-2009, 07:31 PM
If your using a narrowband, which i assume it is being bought from halfords, there a waste of time, about as accurate as a blind man in a darts compettion.

steelie600
12-09-2009, 07:35 PM
yup its a narrow band alan, im going to get me money back and get a wideband from demon tweeks. If in doubt break the snap on scanner out!!!

Turbo_Steve
12-09-2009, 10:31 PM
Demon Tweaks!!!! Are you made of money!!?

Have a look at Innovative and PLX devices and the like.....especially if you're considering an ECU.

Davezj
12-09-2009, 11:33 PM
VR4-Fan, you haven't mentioned what AFRs you're running?

steve just read through the thread and thought this was the case.

doesn't this VR4-Fan chap tell us in other threads he can only get crap fuel where he is form 95 octane at best but sometimes lower.

from my test with 95 octane fuel and WOT, the ecu pulls the timing to the absolute max to try and kill the the pre det/knock you will be getting.

and that is on staock boost, auto, PFL.

i assume that ecu pulling the timing to try to negate knock, will adversley effect performance.

please correct me if i am wrong on this one.

massive aside:-
By the way i hope VR4-fan had the TCL swithed off when trying to do his 1/4 mile runs.

Turbo_Steve
12-09-2009, 11:47 PM
Dave, I believe he runs ultra-high octane fuel for his drag runs (105 or similar). Not sure how it stacks up against UK fuel...this was the source of some debate.
That aside, yeah, 95 RON is bad.

elnevio
13-09-2009, 12:25 AM
Dave, I think the Dominican Republic use MON, not RON, and it's quite possible that he has been using a 99/100 RON equivalent fuel. MON is several 'point' lower on the scale, as it were.

And as for TCL? Well, at the Pod in June, I inadvertently left it on for one of my runs. The TCL one was in fact my second fastest run, and the difference in 60' times between that run and my fastest one, was just one ten thousandth of a second! That's right, 0.0001 seconds difference!