Power outputs??????
Discussion
It depends on how you measure 'power'.
If you do a rolling road then the only figure that is guaranteed is the 'at the wheels' figure - everything else is 'calculated'.
The manufacturer will test a standard engine on an engine dyno and measure the power directly.
I know most e34 M5's were about 20bhp down on the stated 340bhp when rolling roaded, but a rechip sorts this out nicely.
If you do a rolling road then the only figure that is guaranteed is the 'at the wheels' figure - everything else is 'calculated'.
The manufacturer will test a standard engine on an engine dyno and measure the power directly.
I know most e34 M5's were about 20bhp down on the stated 340bhp when rolling roaded, but a rechip sorts this out nicely.
My M3 EVO went on vixpy1's rolling road a couple of months ago. Result was 236bhp at the wheels, corrected to ~285 at the flywheel.
According to Charlie, typical EVOs they measure come out at 285-295 at the flywheel. So, some way from the claimed 321.
Although why people bother with these made up flywheel figures is completely beyond me. The only real comparison is what you're getting at the wheels...
outnumbered said:
My M3 EVO went on vixpy1's rolling road a couple of months ago. Result was 236bhp at the wheels, corrected to ~285 at the flywheel.
According to Charlie, typical EVOs they measure come out at 285-295 at the flywheel. So, some way from the claimed 321.
Although why people bother with these made up flywheel figures is completely beyond me. The only real comparison is what you're getting at the wheels...
agreed totally....its to bump up the figures so people think they are getting something when they are not...I know it annoyed me when I took my Chimaera on a rolling road and got 215@the fly wheel when i was expecting 240...only to be told "that is actually quite a healthy one!!!". I may do the same with the new one to figure out if the car is healthy (which it certainly feels to be). I drove a few on test drives and it was the best by far.
Most BMW's I have seen on rollers are all down on claimed power. Most e30 M3's only make about 190-210 irrespective of model, except Evo Sports which normally make about 220, (claimed 238).
I think their power claims are from chassis dyno's with no ancilliaries attached like air-con etc + the very very best petrol around.
I think their power claims are from chassis dyno's with no ancilliaries attached like air-con etc + the very very best petrol around.
From experience, I've never seen an Evo put out near 321bhp, even on the most optimistic rolling roads.
Its funny, because the non M BMW's tend to make power on the Rollers, and yet the Evo and the E39 M5 both don't get near ( A good M5 will put 380bhp at the fly)
As has been stated though, its whats at the wheels that counts. A chassis dyno cannot 'Measure' flywheel figs on a car (no, not even using coastdown). It is always an estimate!
I have yet to test an E43, but it would be interesting to see what the results are. I've heard good things about the CSL's power.
Its funny, because the non M BMW's tend to make power on the Rollers, and yet the Evo and the E39 M5 both don't get near ( A good M5 will put 380bhp at the fly)
As has been stated though, its whats at the wheels that counts. A chassis dyno cannot 'Measure' flywheel figs on a car (no, not even using coastdown). It is always an estimate!
I have yet to test an E43, but it would be interesting to see what the results are. I've heard good things about the CSL's power.
vixpy1 said:
I have yet to test an E43, but it would be interesting to see what the results are. I've heard good things about the CSL's power.
Despite the comparitive traction deficiency compared with my GT3 once we're up and running there my brother's CSL loses almost nothing to it in the drag. Except when aero really comes into play >160mph. And that's a 381 GT3 by the way.
I suspect 355hp was conservative. That or I've got a lemon GT3.
Sam
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