EricL

link:
http://www.activeautowerke.com/dyno/...%2001%20M3.asp

A 540 vs a new M3. Tell me that the M3 is loosing that much HP to the rear wheels

JSuppi

I think that seems about right, I think the 540 is a V8 while the M3 is a V6. I could be wrong though. Besides they both run in about the same price range :p

GoldTypeS_RENAMED

I think the concern here is that a MANUAL transmission car is losing 26% of it's power at the wheels. That's AWFULLY high for a RWD manual and even worse than our FWD automatic. The 540i on the other hand is only losing 13% at the wheels. I find it hard to believe that two 6spd trannies from the same manufacturer differ that widely. Hell... who knows if the trannies are even different??

Also, edmunds.com has the new M3 listed at 3415lbs. That's only 100 lbs LESS than a CL-S and yet this car is doing 0-60 in under 5 seconds?? Something smells fishy....

[ 08-04-2001: Message edited by: GoldTypeS ]

SinnedTL

Plus that is the older 1997 M3, the ratings are about right, the old M3 had about 250 hp, but the new one supposedly has 333 hp...just about right

GoldTypeS_RENAMED

What are you talking about? The dyno says the 540 is a 1997 and the M3 is a 2001??

Zootking

Im not so sure that the dyno read out there is correct. I could be wrong and I dont have proof, but a fried down here in Charlotte, NC took his 2001 M3 to the dyno today and posted 337 freakin horses. Every magazine says that it has 333, but thats probably to the crank. Somehow the 247 doesnt sound right. Oh well, that's just my opinion, I could be wrong.

DtEW

It's kind of counterintuitive, but I guess it could be so.

Note how the M3 arrives at its 333hp (3.2L, mediocre torque, high rpm) and how the 540i arrives at its 282hp (4.4L, high torque, mediocre rpm). In the absence of anything else, what these to-the-tires losses tell me is that the resistance equation of everything between the flywheel and the tires are more of a function of rpm than torque (at least in the ranges we're dealing with, that is).

If you're having problems understanding the hypothesis, try this. Say we have a massively tweaked 540i engine with an 8000 rpm redline and an M3-like flat torque curve w/the 540i-like 325lb-ft peak. This theoretical engine would put out something just short of 500 horsepower. At the 7250rpm that the M3 engine is showing to be losing about 26% of its horsepower, this engine should also show similar losses.

OTOH, if BMW told us how much power the M3 engine makes at 5750rpm @ the crank, we would probably also see that it loses something closer to the 13% of the 540i.

Of course, none of the above is proof; they're just illustrations of a theory attempting to explain why such losses may not be so counterintuitive.

If you agree the theory seems sound, consider what this implies for the 9000rpm S2000 and the upcoming 10,000rpm RX-8.

AudiAce

Most dynos for the M3 I've seen range from 270-290 RWHP. Also that test was done on a Mustang dyno, which yields about 10% less WHP than the standard dynojet. A car that heavy cannot run 107 mph traps without some serious HP.