i was talking to my freind last night and he use to race bmw's and is still a bmw mechanic. he told me since my hp and torque come together at roughly 5200rmp's that i should shift at about 5200-5500. i was wondering how this would work witht he no lift shift feature. would the throttle cut off at 52-55 or would i thave to go up to the 60-63?

 

Assuming you're still stock, peak HP comes @ 5300rpm. I would suggest aiming for 5900~6000rpm. Short shifting anywhere before that will most likely net you a slower time. It's the "power under the curve" that matters. And, remind your mechanic friend that torque is what gets you off the line - horsepower is what gets you down the tack. Most dyno sheets will show the HP and TQ figures crossing at 5200rpm. That's because it's a mathematical equation. It doesn't matter if it's a Procharged LS1 Camaro or a Honda with VTEC yo. The numbers should always cross at 5200rpm.

 

Exactly, you also have to remember that the higher you go in the current gear, when you shift you will be that much higher/closer to that "peak" hp/tq rating, thus pulling harder. All in therory of course This is all to an extent, but thats how i've always tryed to explain it.

 

All I know is that when I NLS at 5800 RPM, there is no bog in the next gear. If I NLS at 6000+ RPM, the next gear bogs.

HP=Torque*RPM/5200. At RPM=5200, HP=Torque*5200/5200 or HP=Torque.....Hopefully your BMW mechanic knows that.

 

yah i dont think he fully gripped the part of the no lift shift feature ... and a question on the nls.... dose the comp hold the rpms that the cars clutch was pushed in? if so how long? sorry im a noob still

 

AND... if you were to check in a great amount of detail the rate of acceleration and the torque curve. They would match. A cars rate of acceleration is matched to its torque curve, regardless of hp. But, since hp is calculated from tq, more tq up high will result in more hp.

This is dated but the principle is still the same. http://vettenet.org/torquehp.html
I will say having torque at both high and low rpm is even better!

All things stock, I'd say like others have said. 5800-5900. If you get tuned and free up your breathing a bit via intake or factory airbox mod, you can go to redline.

 

so if i shift fast enough at 5800-5900 the car should not bounce up to redline it should be electronicly controlled?

 

yeah if you want to NLS.... I'm not sure if it would work at 5900 or not. Maybe someone else knows. But 6K or so seems to work.
It's never going to let you go over 6300... but you also don't want it hitting that mark. It's hard on the it.

 

ok the main thing is i cnt blow the engin no lift shifting

 

Computer holds rpms if you engage the clutch at WOT within a certain number of RPMs of redline (I don't know what number that is, but never have a problem doing it at 5800). You have to make the shift within 1/3 of a second. If you did it right you should hear one slight "pop" from the exhaust. If you hear more than one, you need to shift faster.

http://www.youtube.com/watch?v=OVl-ke6yOEk When he shifts to second, you can hear it pop twice (he was just a little slow) When he shifts to third at the end you hear the one pop...perfection.

 

ok thanks