Quote:
Originally Posted by pbonsalb
I have a turbo E36M3. In 4th gear on a Dynojet in SAE, it makes 170 lbs rwtq and 80 rwhp at 2500 rpm, 517 lbs and 400 rwhp at 4000 rpm, 440 lbs and 500 rwhp at 6000 rpm, and 360 lbs and 480 rwhp at the 7200 rpm redline. The tires are 255/40/17. I find that in 2nd and 3rd gears, where the torque multiplication is higher, the torque comes in so hard and fast that I often lose traction and that once I lose traction, I do not regain it (maybe because the car is going sideways and I back off. From 3300 to 4000, it gains about 225 lbs rwtq, and this is usually the window in which the traction disappears. I have often wondered whether a more gradual power torque delivery would help with traction, and have considered the idea of running a bigger turbo to shift power higher while also increasing top end power and torque. I view more "linear" as more "gradual."
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Bad ass vehicle.
In my opinion, the tires are screaming (literally) for mercy because they are getting a stupendous amount of torque thrown at them, and the fact that the torque curve ramps up so quickly is not an issue.
As an aside, street tires (even sticky ones) tend to "go away" pretty rapidly once they pass around a 10% slip rate - which is the point where they show best traction, by the way. At a thirty or forty percent slip rate, it's starting to feel as if you're driving on ice.
Slicks don't peak, traction-wise, until they're slipping in the thirty to forty percent slip range, and fall off the traction curve way less rapidly.
Bruce
Edit: PS - Still waiting for MKE_M3's explanation.