Originally Posted by dcstep
You seem most concerned about rolling, street starts in 2d gear. If so, get the 4.10 and raise your rev limit to 8600 rpm and try to control the start so that you're up above 4k. The engine gains hp right up to the redline and doesn't have a huge drop off in torgue, so you can shift around 100-rpm before redline. Still, keep an eye on the other car's momentum, a short shift may be called for if you it starts closing after you've been pulling it.
The torque/hp characteristics of cars differ so much that the best strategy is hard to generalize, but much has to do with the speed at the rolling start. Turbo drivers will want to be a little ways below their torque peak, so they can pull some good acceleration and shift up without dropping too far below their power band. With a stock M3, staying in the top half of the tach is really, really important, but the engine is otherwise very flexible, so that you just need to keep the foot on the firewall and shift quick.
thanks a lot usefull post