E36 M3 - Power at the wheels?

[andy97]

Can anyone tell me what he power at the wheels of a 5 speed 3.0 litre M3 should b e please ( assuming all ok ). I know what the manufacturer quoted figures are, but these are at the flywheel, I assume. Thanks.

[Vixpy1]

It totally depends on the make of dyno

[andy97]

Yes, I understand that dynos differ, but surely a ball park figure is possible, plus or minus 2-3 %?

[Jon_Bmw]

e36 m3 evo with S50B32 257bhp. Factory Flywheel power 321
Z3M Coupe with S54B32 262bhp. Factory Flywheel power 325

Dynojet single roller that is designed to do WHP not flywheel.


Not quite what you are after, but I dont think we have dyno'ed a 3.0 one. I would have to check tomorrow.

[andy97]

Grateful for you help. So, whp seems to be about 80% of flywheel hp?

Therefore it' seems reasonable to estimate that the 3.0 M3 to give approx 228 at the wheels? Or very approx, 190 Bhp per tonne for a basic spec stripped out race car that I estimate to weigh about 1200kg??? (I haven't weighed it yet either, I'll do that when I get it out on a track or text day)

[MarkwG]

Jon_Bmw said:

e36 m3 evo with S50B32 257bhp. Factory Flywheel power 321
Z3M Coupe with S54B32 262bhp. Factory Flywheel power 325

I understand the M3 Evo 321 flywheel figure to be in PS, rather than BHP - in BHP it's 317 (it gets misquoted all the time due to poor translating back in the day.

[iguana]

All dynos read differently, you need to go to the one/ones specified as control for your series.

I've dyno'd a pair of my 3.0 m3 at a local dyno that seems not as optimistic as most, but have the calc'd flywheel fig not the at the wheels figs. 265 & 275.

[andy97]

iguana said:

All dynos read differently, you need to go to the one/ones specified as control for your series.

I've dyno'd a pair of my 3.0 m3 at a local dyno that seems not as optimistic as most, but have the calc'd flywheel fig not the at the wheels figs. 265 & 275.

Thanks for your help - the figures are very useful.

I fully understand the issue of using the "control dynos", but one race series I am considering has classes based on power to weight, but has decided that to reduce hassle for the competitor there is no longer a control Dyno. Instead we have to nominate our power when we register/ enter races and they may Dyno us on a mobile Dyno at the circuit.

I will get the car on a dyno but I'd like ball park figures to help me with my series choice before I even go near a Dyno.

[Jon_Bmw]

Mark,

You are probably right.


Andy,

Sorry I forgot to check for B30 engine cars. I will try and check tomorrow.

One thing you will have to be careful is that the WHP figures will vary massively if it is a single roller or twin roller setup. A bit of googleing brings up this:

http://www.bimmerforums.com/forum/showthread.php?4...

Which shows wildly different results from one dyno to the next. It really is difficult to use two or more different chassis dynos to submit Power/weight figures for race cars. All the smart competitors will go to one that reads a 'low' WHP figure.