My Graphs from todays RR

[aboo]

33400

33401

[phosty]

Mine:

uploaded/4134/1269722075.jpg uploaded/4134/1269722280.jpg

Discussed here : http://www.clubvr4.com/forum/showpost.php?p=528197&postcount=50

[Davezj]

can you guys tell us what power figure was measured, the wheel power or the engine power. as they don't seem to tie up with eachother.

if i assume aboo wheel power figure is the correct one and he has a manual, then the engine power would be
248 / 0.76 = 326 bhp not the figure quoted on the graph 288.

it looks like they only aloud 14% for transmission loss and not the 24% that the club use as standard.

[aboo]

At the wheel Dave I think & mine is auto.

Phosty was also saying that Dastek claim that, that is the reading you dont add the 7%

[Davezj]

point i was trying to make was the engine power doesn't make any sense at all.

if your is an auto aboo then
248 at wheels
when you take into account the transmission loss and auto box then
326 / 0.93 = 350 bhp for you Aboo that is excellent.

[Nick Mann]

All rolling roads measure at the wheels, AFAIK. And I'd be gobsmacked if any 4WD auto can have total losses of less than 15%.

Some good numbers there chaps! :D

[aboo]

I'm well chuffed.

It was the first time I'd heared the zorst from the outside of the car on full chat,I liked & to see flames when he let of the loud peddal was good to see.:)

[phosty]

I will agree that the losses estimated/calculated (take your pick) by the Dastek dyno seem low - but I also subscribe to the camp that don't believe a gearbox and torque convertor always take 24% and 7% no matter what your power output.

Safest thing as always is just to quote wheel HP - that's measured!

Compared to the earlier runs at Hypertech in December I think these are consistent - I was running less boost last time and Andy hit the speed limiter because they didn't know how dyno a auto VR4.

[aboo]

Compared to the earlier runs at Hypertech in December I think these are consistent.

Have to agree with you Phil. Was just looking at the graphs from Hypertech & there much & such the same except my boost is abit higher with todays runs.

[phosty]

Davej, just to recap on how Dastek 'Calculate' true transmission losses see here:

http://www.clubvr4.com/forum/attachment.php?attachmentid=32784&d=1267553878
http://www.clubvr4.com/forum/attachment.php?attachmentid=32785&d=1267553878
http://www.clubvr4.com/forum/attachment.php?attachmentid=32786&d=1267553878
(from http://www.clubvr4.com/forum/showpost.php?p=518902&postcount=16)

[Davezj]

there is a lot of info there.

yes i would have to agree that wheel power is the only figure that matters.

my last dyno gave me about 180 bhp at the wheels on a totally stock VR4. so 248 and 225 are really good results.

[Nick Mann]

225 is a very good result. Over 230 is not seen often. 248 is awesome!

[apeman69]

I've heard from 2 very knowledgable chaps that most VR-4s struggle to make 200 at the wheels with or without all kinds of mods, albeit on the much-favoured and much-used DynoDynamics dyno. Mine produced 'only' 214 ATW with the cr@p loads of mods I've had done.
Surely Mitsy's quoted power figures are ATF (260/280PS approx 256/276BHP), this being the higher of the two figures and an obvious marketing factor.
If my Mitsy assumption is correct then I'm sceptical about a 14 year old PFL auto producing 249BHP ATW and am pleased that mine is up to 214ATW/296ATF.
Looking at the Eurospec rolling road day results then most everyone else's cars look pretty under-powered compared to these two examples, working back the calculation from fly to wheel power and using the 24% & 7% losses where appropriate.
(To me) this shows once again that there is no conclusive and accurate method of comparing power outputs when using different dynos and the drivetrain losses cannot be measured hence the assumed figures.
Am I talking b@lls again? /drinkswine

[Davezj]

i was assuming that both aboo and phosty had a massive amount mods to achieve.

[apeman69]

:furious4: Dunno Dave but if these figures are correct and comparative then I'm either:-
1) Going to Scotland to have mine on the dyno :joker: (who needs New Zealand?)
2) Selling my car because, even though it goes like an exocet, the power output is chronic :anxious:

[aboo]

I dont know how all this work but I managed a 14.418 run at Crail in the pissing rain back in November 1st & managed to out run a Scoobie wrx ( the one after the bug eye one) tonight on the way home from the wifes mums house with the wife & three kids in it & 3/4 a tank of fuel.

Was watching the Scoobie fall back in the mirror & the kids were hanging over the back seats laughing at the guy in the Scoobie & he was trying cause when we came of one of the roundabouts I saw the arse of the Scoobie twitching. He gave me a flash & a thumbs up as he turned off.

So I'm thinking these results are about right.

[aboo]

i was assuming that both aboo and phosty had a massive amount mods to achieve.The list of mods are there for all to see.

[elnevio]

On the Eurospec Dyno Day last year, I got ~202bhp ATW. The fly figure was about 286. Andy's mods are virtually identical to mine at the time. So our fly figures are about the same.

[Davezj]

so the only mods you have are these,

RPW downpipes
scorpion De-cat
S/S exhaust from cat back
K&N panel air filter
HKS copy BOV
Tien springs
MBC at 12psi
Magnecor KV85 HT Leads
NGK Iridium spark plugs
17" Konig E-Racer hyper grey wheels
Tan leather seats
Ralliart carbon dash & chrome gear surround

so in reality, it is full exhaust, air filter, mbc 12psi, decat. and that gives 60 bhp more at the wheels. 185 bhp at the wheels is about average for a stock PFL auto VR4.

seems a bit high to me. but if i got a result like that, i would be very happy.

[aboo]

No one has said anything about how smoooooooth my run was:).

I'v been on a high since I saw the graph

[aboo]

so the only mods you have are these,

RPW downpipes
scorpion De-cat
S/S exhaust from cat back
K&N panel air filter
HKS copy BOV
Tien springs
MBC at 12psi
Magnecor KV85 HT Leads
NGK Iridium spark plugs
17" Konig E-Racer hyper grey wheels
Tan leather seats
Ralliart carbon dash & chrome gear surround

so in reality, it is full exhaust, air filter, mbc 12psi, decat. and that gives 60 bhp more at the wheels. 185 bhp at the wheels is about average for a stock PFL auto VR4.

seems a bit much to me. but if i got a result like that, i would be very happy.Yes looks like it but 13.5psi going by the run today. Maybe it was a well looked after VR4 before I got it & has been since.

[phosty]

I hear what you're saying - 2 years ago I took my silver legnum (totally stock) to this same Dastek dyno at Wallace and then two days later to a DynoDynamics dyno at Japerformance.

I got 202 whp from the Dastek and 183 whp on the DynoDynamics. So the readings on the Dastek were ~10% higher than the DD dyno.

http://www.clubvr4.com/forum/showpost.php?p=518902&postcount=16
http://www.clubvr4.com/forum/showpost.php?p=518915&postcount=18

So make of that what you will - which was correct? Impossible to say. Dynos are just good for back to back comparisons, not absolute numbers.

You can't argue with 1/4 mile times though!

[Davezj]

the graph is a corrected engine power graph, not the actual wheel power measurement. so you don't really know how the power was delivered it might have been smoothed. it should not have been but why give you the corrected engine power graph and not the ATW power graph.

corrected engine Power V speed (MPH) graph is not ver good. it doesn't really show you anything.

it should be a ATW Power V RPM which would show how the power was delivered at what RPM.

[apeman69]

Nice story about the scooby... like that! /woot
I'm not having a go at you. My gut instinct is that something doesn't quite add up. The fly figure looks comparative to many others on here. The wheels (which has been measured) is phenomenal in comparison. Maybe the Eurospec figures are questionable? Who knows? If I ever get the opportunity to visit Scotland I'll have a trip to that dyno place if just to put my mind at rest. I'll shut up now and open another bottle...

[elnevio]

Yes - very smooth. And similar in smoothness to mine!

So, my thinking is this - the Dastek RR can't measure the ATW figure on autos accurately (probably due to the TC, etc. etc.), but the correction factor that's applied is about right to get the correct fly figure.

Either way, it's the area under the curve you really notice when giving it beans! :afro:

[phosty]

Good point Davej. If I understand how the Dasteks work then there will be a variable tranmssion losses curve which has been overlaid onto the whp curve to arrive at the final FlyHp curve. I'll ask dastek if they can print that out too.

If you zoom in on mine you'll see that there are quite a few small wobbles on the graph so I suspect it is sampling (or at least displaying) without too much smoothing.

The autos were all done in 'Inertia Mode' whereas the manuals were done with a fixed ramp rate. Which is probably why mine fuel cut which it doesn't do on the road.

[Davezj]

phosty result are better at least they are power V rpm but it stops a 4200rpm max power is normally developed at about 5500rpm so they have not even reached the max value.
you can see in the graph from phosty that it is still rising at 4200rpm but the graph stops at that point. a bit odd.

[phosty]

The chap explained that due to using inertia mode on the Autos that they only output a true speed signal (from the rollers) against the power, not rpm.

My DynoDynamics run was also against speed not rpm.

The reason mine stops at 4200 rpm is because it fuel cut there.

[Wodjno]

33400

33401

You got some nice AFR's there /yes Should be producing some nice torque from those /Steeringw

[aboo]

http://www.clubvr4.com/forum/showthread.php?t=44294&page=2

if you look at this thead post 38 you will see my graphs from hypertech in December but it was hitting the limiter cause he was running it in 4th & hit the limiter.

Not having a go guys just trying to get a grips with it all

[aboo]

You got some nice AFR's there /yes Should be producing some nice torque from those /SteeringwGoing by Phosty's graphs should be in the 300's

[aboo]

I'll have to get myself to eurospec to see how the three match up:)

[evonut270]

Going by Phosty's graphs should be in the 300'syou could make a bit more running 12AFRs and some better boost control higher up the revs

[Davezj]

well that is a good result. as you can deal with fuel cut and power will continue to rise for another about 1500rpm, excellent result.

i don't see any point in a power v speed graph at all, i am sure some will be able to open my eyes on this one.

As to the operation of an inertia dyno i am none the wiser, i was always told to steer clear of them with an auto's. not sure why!

[dinger1983]

ok think scotland is limited on what they have i beleave walace ,star,dastek and extreme all run dastek rollers and hypertech run dyno dynamic and since it seems that the dastek rollers aint any good with the auto i may have to go back to hypertech

but i cant see there being much of a diffrence between mine and andys cars

[Davezj]

http://www.clubvr4.com/forum/showthread.php?t=44294&page=2

if you look at this thread post 38 you will see my graphs from hypertech in December but it was hitting the limiter cause he was running it in 4th & hit the limiter.

Not having a go guys just trying to get a grips with it all


the graphs in post 38 look about right, showing 180,185 ATW bhp and the measured ATW power is already on it's way down at 6000rpm which is normal. this is massively different to the 248 ATW bhp in you last Dyno run.

i just don't think the guy knew what he was doing when testing a auto VR4.
i have only ever seen them tested in 3rd gear in tip. so you will not hit speed limiter if it is still active. and no gear changes.

i would not have thought there are not many dyno places that will have tested powerful autos on a regular basis., if at all. most power full autos are stupidly expensive mercs, bmw, audi, etc, and these are owner by middle/later aged managers that are not interested in dynos testing.

don't be disheartened if you get it tested again on a dyno dynamics machine and you loose 60 ATW bhp for no apparent reason.

the only real way of monitoring improvements is to use the same dyno machine operated by the person in the same way. it is just like anything else you do, different people do thing different ways and use different tools to achieve the result. however the results will be different.

[Gowf]

you could make a bit more running 12AFRs and some better boost control higher up the revs


You would think that but no. I'm fairly certain that Ben and i were the only ones to try this out when mapping my car.

So we had a few cans of 109 fizzy fuel in the tank when dynoing it, the sweetspot of ignition was found, but moving the afr from the high 11's, to the mid 12's made no difference to power output.

Now, on pump fuel you will get nowhere near that, not unless you want to back your boost off considerably. The problem you've got with the stock turbos is that when they are making 1bar or whatever boost they are working pretty damn hard and generating a huge quantity of heat. So you really do need the extra fuel in there to prevent knock.

The last run we did on mine on pump fuel had 3 major knock events, and that is with an afr of 11.5. yes ok timing and boost have a major role to play, but the safest way to prevent knock is to cool, and thats where the extra fuel is invaluable.

Anyway, Andy not bad results there at all mate. Why was it run with speed as the independant variable? just be sceptical of these figures as it is not a dyno dynamics dyno. Now you can say all you like and this debate can go on forever, however what is industry standard? Dyno dynamics is. With regards to dastek, tbh I have used them and wasnt impressed, and i know a lot of other people with big power cars in scotland dont trust the figures either. Nevertheless, it would be good to see your on a DD machine for a comparison. This is not a go at you, or slating your car so please dont take it that way, its just a opinion.

[aboo]

Not sure why it was run at Speed. I'm not taking any of this personaly its good to hear peoples opinions.

I think a trip to eurospec in the summer is the next step to see how they all compare.

[Davezj]

i would like to say sorry aboo, none of these comment are personal and directed at you. just at the way the dyno run was carried out.

very sorry i did not make this more clear at the beginning, it must have sounded like i was having a go at you. it was not meant to be.

i am glad you are a reasonable man, reading some of my post it did sound like a bit of a barrage of comments dissing your dyno result. i think i was a bit caught up in the moment of quick posting. i do apologise if any offence was caused.

[Kenneth]

What sort of dyno is a Dyno dynamics? If it is RR dyno, then it is also measuring speed surely?

Put it this way, if you are measuring the torque at the wheels, through the tyres, then the only measure you have is the speed at which the weels can rotate and the rate at which they can accelerate a specific mass or braking force.

[aboo]

The RR meens rolling road Kenneth.

Dave no need to apologise. Most people who have met me will tell you I'm a very reasonable man :) . As I said its your opinion.

The way the guy had to get the auto to work with the dastek RR was. He run the car in 3rd to the redline in trip then go back through into N. Cause it works (I think) by running it to redline then the car slowing on its own if that makes sence.

[Gowf]

What sort of dyno is a Dyno dynamics? If it is RR dyno, then it is also measuring speed surely?

Put it this way, if you are measuring the torque at the wheels, through the tyres, then the only measure you have is the speed at which the weels can rotate and the rate at which they can accelerate a specific mass or braking force.


Yes you measure speed, but that speed is translated into rpm when you initialy set the car up on there. Power verses speed is not useful at all really.

There are various ways in which this artificial load can be applied and therefore measured. Some providing far more accuracy than others. Ben will be able to tell you a lot more on this than i can. But from what i have heard, inertia dynos allow ramping up to occur, so as time goes on you require less tractive effort to gain the same speed in the same time although it believes your applying more.

[Kenneth]

My only point was that surely speed was the direct thing being measured and therefore all the dyno results are directly resultant from that effective road speed and the rate at which it either accelerates or how much braking force is required to control the acceleration.

Sure, it might not be so user friendly to look at if you are interested at what RPM you are making those figures, but it is easy enough to re-plot yourself.

And surely RPM is taken from the engine rather than as a speed calculation? tyre swell, tyre slip, clutch slip, torque converter slip etc would all cause that sort of calculation to be pretty questionable.


My whole point is that I can't see that viewing the chart with speed on the X axis makes the results in any way questionable based on that fact alone.

[Gowf]

I never said that they were questionable due to that at all.

Ok.... take the way things are meant to be dyno'd, engine dynos, are you interested in road speed then? So when using a chasis dyno you should have the same output graph scales as what youd expect if you whipped your engine out and put it on a true dyno.

However all your measuring is an at the wheels figure, which is pretty close to what youd expect on the road, the rpm value isnt going to change.... yes if you start spinning the wheels on a dyno then you will get some odd results, same as if you hit the brakes on the way back down. BUT when you initialy run the car to set it up these things are taken into consideration, as you take a value of rpm for that gear for a speed (shown from the ecu), so its still speed related when running for power.

My main point was you shouldnt have to replot yourself... you are paying for the service

[HOODY]

I'll have to get myself to eurospec to see how the three match up:)
Im off to Eurospec for a rolling road session on sunday 13th June if you want to meet up

[phosty]

I read some interesting info on the topic of transmission losses and dynos a while back but couldn't find them in my Favs. Anyway, found them again:

http://www.pumaracing.co.uk/trans.htm
http://www.pumaracing.co.uk/setup01.htm

And on the merits of wheel HP vs Fly HP:
http://www.pumaracing.co.uk/coastdwn.htm

And a bit on Dasteks:
http://www.pistonheads.com/GASSING/topic.asp?h=0&f=66&t=608679&mid=0&i=0&nmt=Dastek%20Unichip...&mid=0

[Wodjno]

That Puma racing site has some great info .. I had lost all that info I had stored when 1 of my old PC's crashed. :-(
Found that site about 10 years ago, but forgot all about it.

Great re-find :D

Wodj

[Roadrunner]

I read some interesting info on the topic of transmission losses and dynos a while back but couldn't find them in my Favs. Anyway, found them again:

http://www.pumaracing.co.uk/trans.htm
http://www.pumaracing.co.uk/setup01.htm

And on the merits of wheel HP vs Fly HP:
http://www.pumaracing.co.uk/coastdwn.htm

And a bit on Dasteks:
http://www.pistonheads.com/GASSING/topic.asp?h=0&f=66&t=608679&mid=0&i=0&nmt=Dastek%20Unichip...&mid=0

Good articles. So, "If you are starting from a wheel bhp figure then you have to apply those equations in reverse - add 10 bhp then divide by 0.9 for FWD or 0.88 for RWD to get back to a flywheel figure", can anyone take a stab at what equation should be used for 4WD? /Hmmm

[Davezj]

the standard and well used numbers are 24% for 4WD and 7% for auto box.

ATW HP / 0.76 = 4WD correction (24%).

then if you have a Auto Box,

4WD Correction / 0.93 = Auto box correction on top of the 4WD correction (7%).

it is not fool proof method of working things out, especially when you get to higher power figures, it is obvious that they don't work. there is a limit to what the 4WD and auto box will sap from the engine. what that figure is i don't know.

[Roadrunner]

the standard and well used numbers are 24% for 4WD and 7% for auto box.

/thankyou :thumbsup:

[Turbo_Steve]

Transmission loss (in any setup) will be 3D curve, and will vary dependant on ground speed, fluid temps etc etc etc. Not helpfully accurate, I know, but I don't think anyone has a specific model for the Evo, let alone the VR4.

[Davezj]

it is one of those enigma values, as long as we all stick to the same values it does not matter if they are correct or not it just gives a ball park figure every bodies car is different it is just a comparison value.

however and you know there is always a however with me,
if you have an engine that has been dyno'ed at avalue "A" then if you put that in 5 different cars of the same make and model and use the standard values, then you would get 5 different ATW power figures.

it is the way of the world.

[bradc]

And if you took that car to 5 different dyno's it would make 5 different power figures!

[Turbo_Steve]

And if you took it to NZ it would gain 20% :D

[phosty]

Strong argument there for a 1/4 mile time being the only measurement you can't over estimate...

[aboo]

See what mine does on Sunday.

[Wodjno]

And if you took it to NZ it would gain 20% :D
/catfight





















































:laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh: :laugh:

[Turbo_Steve]

Strong argument there for a 1/4 mile time being the only measurement you can't over estimate...


Apart from the windspeed.


And, of course, we'd all have to use the same quarter mile - some of them aren't flat. Including Santa Pod.

[aboo]

To update this I got a 13.908 on the 1/4 mile with glove box full of crap, leather seats, tools, spare wheel & tools in the boot.

[Davezj]

that is a cracking result, i keep on meaning to get my g-tech out and give it some beans on a 1/4 run just to what the ball park figure is for my car.
but not until the oil seal beds in a bit.