BHP

[francisjonno 2]

Earlier this year my VR ('97 OBD2) went on a rolling road (@ at BMW Club RR day).

Last night I was looking at my dyno plots and it produced 172bhp and 177lbft at the wheels, the tranmission lost was calculated for my specific car at 37.8 (by doing a number of load runs on the car - i'm not sure how this is really calc'd but know that calc'd flywheel fig's are less than perfect!) .

By my reckoning that would give 209.8bhp at the flywheel (do you add trans loss to torque as well?). The only mod i've done is the airfilter (a previous owner may have done something but nothing visable).

The car runs well (will keep up with my mate's S3 & WRX). The BMW's at the RR day produced exactly what they had expected in terms of wheel and flywheel figures - same fig's as on AMD's RR (a couple of the BM's produced a lot less than BMW claim!). The guy at the RR had seen a VR produce similar fig's on his rollers. But is a transmission loss of 37.8 high for a VR? Or is it likely that my car is chipped or something?

I'm v happy with my car and want to put it on another RR for a second opion !lol but would like to know what you guy's think.

[Nerih 0]

thats sweet power for a n/a motor, maybe it has cams or something, becuase 209 would put it near the top end of n/a, pete has a few mods to his n/a, you should compare power with his, since he *is* i think going for max n/a power.

[seadog 0]

for just a filter thats a very healthy figure altho i would look into it further n see if anythin internal has been done? i`ve got an obd1 wi schrick manifold, schrick cams (260/264`s), miltek, k&n and chip and when first setup made 211bhp at the flywheel!! i no obd2`s make more power but surely not enough to match havin all those mods?? ?!

[Eat this 2]

mines a healthy motor and i got 152 at the wheels with exhaust decat and filter 198 at the flywheel and torque is what is actually measured then bhp is worked out from that

[six appeal 53]

Might be the very nice cold weather were having at the mo. I've known my BHP differ by up to 20bhp, just cos of the ambient conditions! (and yes that was on the same rolling road, just different times of the year!)

Simon

[silverline 0]

mine was making 184bhp at the flywheel and 153bhp at the wheels. thats a standard engine!

[Nerih 0]

if you do do r&r, then go in the morning, be the first one on the rollers

[francisjonno 2]

Thanks for the info guys

I'm definitely going to have to put it on another RR to see what's going on

[blockquote]Might be the very nice cold weather were having at the mo. I've known my BHP differ by up to 20bhp, just cos of the ambient conditions! (and yes that was on the same rolling road, just different times of the year!)

Simon[/blockquote]

The RR day i went on was in April, so it was a little warmer than now

[six appeal 53]

Not just temperature that effects it though, can be all to do with humidity/density of air etc..... Thats why a lot of the RR's have a print out of the temp./humidity etc....

Simon.

[francisjonno 2]

I'm coming to the December Rolling Road day, so it looks like I'll get my second opinion (fingers crossed it performs like last time!)