My Dyno Result

[jevansio]

OK, so you have a car, it has 100bhp (flywheel) and it has 50% drivetrain losses.

 

It's rear wheel figure is 50% of 100 = 50bhp

 

Reversing the calculation, you were saying I have 50 rear wheel & 50% losses, so I add 50% of 50bhp (which is 25bhp) getting a total of 75bhp flywheel (which obviously isn;t what we started with).

 

What you need to do is divide the rwhp figure by (100 - the loss) as a percent.

 

So from our example rwhp / (100 - 50)

 

is 50 rwhp / 50 * 100 = 100 flywheel.

 

[Supra-Dupra]

She got 337whp, say he didnt give her a fly figure. She comes on here is told 10-12% is a reasonable loss, so she gets picks a figure in that range say 11.86% of the whp, then adds it to the whp, does'nt that amount to the correct fly figure ! Using that the figures add up.

 

Dyno printout figures.

377fly 337whp 40 loss

 

Theory after not getting a fly figure from dyno operator.

(337/100)= 3.37 = 1% whp

3.37(1%) x 11.86 = 40

337+40 = 377 fly

 

Both match.

[jevansio]

OK, so using your above example, a car has 377 flywheel bhp & 11.86% drivetrain loss, what is it's rear wheel horse power?

[Supra-Dupra]

OK, so using your above example, a car has 377 flywheel bhp & 11.86% drivetrain loss, what is it's rear wheel horse power?

 

What ever the dyno tells me

 

377/100=3.77

 

3.77 x 11.86 = 44

 

377-44= 333

[jevansio]

What ever the dyno tells me

 

377/100=3.77

 

3.77 x 11.86 = 44

 

377-44= 333

So you're telling me the car has 333rwhp, but only a second ago you told me it started off with 337 rwhp. So we've lost 4bhp, where has that gone?

[Supra-Dupra]

And continuing from there, 377 - the 44 loss = what?

 

Updated it, pressed post by mistake before putting the final.

[jevansio]

Updated it, pressed post by mistake before putting the final.

Yeah I saw , I've updated my post too

[Supra-Dupra]

So you're telling me the car has 333rwhp, but only a second ago you told me it started off with 337 rwhp. So we've lost 4bhp, where has that gone?

 

So it does'nt work in reverse but Ill never need to calculate whp, the dyno will do that and loss isnt a constant same % anyway, using 22.5% you wont lose 225 on a 1000bhp car !

Edited January 3, 2009 by Supra-Dupra (see edit history)

[jevansio]

So it does'nt work in reverse but Ill never need to calculate whp, the dyno will do that

, I think we'll leave it at that then

[jevansio]

So it does'nt work in reverse but Ill never need to calculate whp, the dyno will do that and loss isnt a constant same % anyway, using 22.5% you wont lose 250 on a 1000bhp car !

No you'll lose 225

[Supra-Dupra]

Got there before ya

[jevansio]

Are there any requirements to understand 1st Year GCSE Maths before joining the club?

[jevansio]

Got there before ya

Aye ya buggar

[Supra-Dupra]

Aye ya buggar

 

Ah ya cheeky git edited my quote.

[jevansio]

Ah ya cheeky git edited my quote.

Well I had to let the world know the real figure

[Supra-Dupra]

Well I had to let the world know the real figure

 

I've been up since 6.30 to go to a dyno day till 5pm, not really absorbing any of this tbh, some sleep and a read over it again is needed.

[Guigsy]

Anyone fancy analysing my dyno printout from a while ago? i never understand them that much

 

Doesnt help the torque is in Nm, the guy who was doing the driving said it was the bigest torque figure he had seen on a bpu car. :S

And i lost 80 odd hp from the fly to the wheels. Is that reasonable?

BPU TT Auto UKspec btw.

 

Have to admit its not the best picture

 

engine - 383 bhp

wheel - 303 bhp

drag - 80

 

torque - 514nm

 

Edited January 3, 2009 by Guigsy (see edit history)