Got 608HP and 660NM

**PRA4WX** · 5 April 2009, 23:46

Not to join in but 034's quoted numbers were done on different fuels IIRC.

**driftin jo** · 6 April 2009, 00:05

Originally posted by PRA4WX

Not to join in but 034's quoted numbers were done on different fuels IIRC.

quote from 034Motorsport Castrol Syntech Top Shop Challenge Results by Javad Shadzi

"We ended up coming in 3rd place, I was really pushing for 2nd, but we were edged out by the 2.1l SR20DET. Our final HP #'s were 848 crank HP and 561 ft/lbs TQ peak 368.8 HP and 244TQ /Liter. This was the tune that we did 703.3 whp here on our dyno, a difference of 17% or so. "

**driftin jo** · 6 April 2009, 00:11

Originally posted by PRA4WX

Not to join in but 034's quoted numbers were done on different fuels IIRC.

Both done with 100 octane

**EspenW** · 6 April 2009, 10:33

Originally posted by driftin jo

Both done with 100 octane

Excellent. Do you know how much wheel torque Javad pulled on the RR?

**driftin jo** · 6 April 2009, 12:03

Originally posted by EspenW

Excellent. Do you know how much wheel torque Javad pulled on the RR?

On that run peak torque was 542 FT/LBS at about 6000 rmp

**urquattro-island** · 6 April 2009, 12:26

I

for one do not understand, why people are so interested in the estimated engine hp.
It is an will always be the whp/wtourque that brings you fastest from a-b. I mean its the whp that is the most interseting, is it not???????????????

**jogi730** · 6 April 2009, 12:35

To throw my 2pence worth in, my understanding is that the only way of getting true and accurate bhp figures is from a dyno and is measured at the crank. All other readings will be estimated to some degree and be dependant/vary on equipment used.
Cheers
Chris

**S2central.net** · 6 April 2009, 13:32

Yeah but wheel horsepower is only useful for people who have a clue about this stuff... Down the pub its crank horsepower which the ordinary man will talk about. I mean that's all the manufacturers quote and what the magazines and media talk about after all. The average guy in the pub has no way to know how much power a brand new Audi R8 puts down at the wheels - but he can tell you the engine is 420bhp (or whatever) by googling it on his iPhone... So it becomes the defacto reference point - that and things like 0-60 or 1/4 mile times which are much more useful.

**EspenW** · 6 April 2009, 13:51

Originally posted by driftin jo

On that run peak torque was 542 FT/LBS at about 6000 rmp

Hmm.. 542ft-lbs on the rolling road and 561ft-lbs on the engine dyno?

3.4% drivetrain loss at peak torque sound kind of low...

**driftin jo** · 6 April 2009, 14:08

Originally posted by S2central.net

Yeah but wheel horsepower is only useful for people who have a clue about this stuff... Down the pub its crank horsepower which the ordinary man will talk about. I mean that's all the manufacturers quote and what the magazines and media talk about after all. The average guy in the pub has no way to know how much power a brand new Audi R8 puts down at the wheels - but he can tell you the engine is 420bhp (or whatever) by googling it on his iPhone... So it becomes the defacto reference point - that and things like 0-60 or 1/4 mile times which are much more useful.

Yes this is true and OK if you talking about a standard car , as i stated in a previous post, a guy who i
spoke with has never in 10 years of working with an engine dyno ever had the crank hp number that was calculated / estimated from a rolling road .Most he said were between 3 -10 % over what they actually made on a real dynamometer , some he said were almost 15% over and the odd one or two 20+% .
suppose it makes for good pub talk.

**driftin jo** · 6 April 2009, 14:40

Originally posted by EspenW

Hmm.. 542ft-lbs on the rolling road and 561ft-lbs on the engine dyno?

3.4% drivetrain loss at peak torque sound kind of low...

That's part of the problem with rolling roads as i see it , real torque at the wheels can be many times more than flywheel , it has to be calculated by gear ratio and loss Correction factors , i.e. If a car at 6000rpm
makes 200 ft/lbs of torque crank then actual wheel torque at 60mph in second gear say with 225/40/18 tire that has a rolling circumference of 804 revs per mile, that's 804 rpm ,then there is 7.46x the torque that there is at fly , or about 1492 ft/lbs without any losses. Its then calculating losses were it all goes wrong.
The roll down test that some people use have been show in the past to be a out by a country mile !
You can see how things can go a stray, when most people quote wheel torque they don't really mean wheel torque they mean calculated engine torque from wheel torque.
Then of course they calculate that into hp by RPM X TORQUE / 5252 .
any discrepancies in rpm measurement just compound the errors also.