MKRocks,
I know many folks will think otherwise, but I think your coworkers are wrong. You want maximum torque at the wheel, not the motor.
Wheel torque is engine torque multiplied by your total gear ratio. When you realize that each upshift reduces the torque multiplier, you can see that it's okay to have the engine torque going down as long as the engine speed increases at a "faster" rate. You want to shift when the wheel torque finally decreases to the level that you will have in the next higher gear.
Perhaps the simplest way to think about it is to mathematically "factor out" the gearing and acknowledge that "delivered power" is what your car needs in order to speed up. Assuming a constant efficiency drivetrain, you will want to shift at a point where your engine makes as much power in the new gear as it was making in the previous one.
With a well-breathing engine, this usually works out to somewhere beyond redline, meaning that all shifts are "short," though it can occur below redline in an engine that wheezes at high speed.
disclaimer: assuming stereotypical torque curve shapes.
An interesting observation is that if your torque curve was linearly decreasing such that your horsepower was always constant, then it wouldn't matter when you shifted!
The M5 dyno charts seem to show just such a situation between 6000 and 7000 rpm.
http://www.bmwm5.com/ubb/Forum1/HTML/001616.html
From the chart, it is clear that you want to keep the engine above 6000 rpm if you want maximum acceleration. There's a reason engines are designed to run fast.
Though the difference is small, you're still making more power at 7000 rpm with only 240 lb-ft, than you are at 5000 rpm with 320 lb-ft.
what is the max speed in each forward gear? and how do u guys like the gear ratios?
i feel completely natural at 95-120, depending, on regular freeway cruising.
Linear Mode
