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View Full Version : Optimal performance in 2004 M3


Kicbax
07-20-2005, 02:44 PM
I recently purchased(March 05) a new 04 M3. Having always owned SUV's this is the first time I have ever owned a "high performace" car. Problem is, I don't think I am driving the car to its full potential. Can anyone give me some pointers on how to obtain optimal 0-60 times/optimal performance? Are there certain sopts on the tach that I should consistently shift at or should I always take it up to 7500 or 8000rpm and let it drop down till 2000 again before I put my foot back in it? (Car is a manual) Thanks.

bren
07-20-2005, 02:48 PM
To get optimal performance you need turns :p


Don't let the RPMs drop between gear shifts.

BMW_Brand
07-20-2005, 02:56 PM
Don't let the RPMs drop between gear shifts.

Make sure you're not shifting like a grandma :drive:

The HACK
07-20-2005, 04:24 PM
http://forums.bimmerforums.com/forum/showthread.php?t=47538

Kicbax
07-21-2005, 10:28 PM
Thanks for the quick replies. I'll keep you posted on how the tips work out. :D

stylinexpat
07-23-2005, 02:51 AM
If you are able to shift without taking your foot off the gas pedal and change gears in under a second then you are in the Formula 1 category :)

Pinecone
07-23-2005, 10:29 AM
That is not hard at all.

Only thing is, if you don't lift, the engine will bounce on the rev limiter until you get the clutch back out again. But shifts under 1 second are not hard.

As for RPM to shift, IIRC the car is geared to need to be shifted at 8000 RPM in every gear to maximize acceleration. The gear spacing is a bit large.

dawgbone
07-25-2005, 07:21 AM
That is not hard at all.

Only thing is, if you don't lift, the engine will bounce on the rev limiter until you get the clutch back out again. But shifts under 1 second are not hard.

As for RPM to shift, IIRC the car is geared to need to be shifted at 8000 RPM in every gear to maximize acceleration. The gear spacing is a bit large.

Nope not hard at all...being easy on second is a little tricky...but you'll probably never have to worry about that on the track... :thumbup:

I could be wrong, but I generally trying to shift right up to 7500 and not hitting redline..To me, it feels that there is a big tq drop off, right shortly after 7k...and really only drops about 800 to 1k rpms in between each shift...In which is what I liked most about the car...flat tq and 6spd= fun

Kicbax
07-25-2005, 08:51 AM
My shifting must be off. I shift about the same sopt, 7500 right before redline, but when I shift into second the tach has usually dropped down to about 5grand or so before I punch it again(Perhaps you can try this out and let me know how the performance compares) Is your foot completly off the gas before you engage the clutch? Maybe it is time for me to look into ///M driving school :dunno:

dawgbone
07-25-2005, 09:44 AM
My shifting must be off. I shift about the same sopt, 7500 right before redline, but when I shift into second the tach has usually dropped down to about 5grand or so before I punch it again(Perhaps you can try this out and let me know how the performance compares) Is your foot completly off the gas before you engage the clutch? Maybe it is time for me to look into ///M driving school :dunno:

:dunno: Not sure how you're shifting...I usually try to make the car and my shifting as linear as possible..but if I find myself in that kind of rpm, I usually don't concentrate on gas vs clutch too much..I've only owned standards in my life, so it's become second nature..
I think I come off throttle guessing about an 1/8 or 1/4 when I disengage the clutch(push clutch in) and back into WOT before I start to reengage the clutch..I shift hard and is the reason I never did the CDV mod..in which doesn't really make that much of a difference other than voiding drivetrain warranty...
Even at slow speeds or normal driving, I shift fast, and hold out the gear in shifting rpm for a little longer, in effort to make the shift more linear....The whole object with a manual, is to match revs vs speed/gear...Using the synchros in the transmission is a bad habit, and using them as little as you can will prolong the life of a tranny...

You may be right about 1 to 2nd though...It may drop revs more than all others..I don't pay attention to 1-2nd shifts as much as I do all others..I will tonight on my way home :thumbup:

spta97
07-25-2005, 12:40 PM
All these tips seem really hard on the clutch / drive train. I would be afraid to launch like that for fear of doing damage to the car.

dawgbone
07-25-2005, 09:08 PM
All these tips seem really hard on the clutch / drive train. I would be afraid to launch like that for fear of doing damage to the car.

HHHMMM..."Launch"...That's a different beast...I know that without burning up the clutch, a launch from and above 2k will promote traction loss...At least with radials..I have yet to slap a pair of slicks on the car, so that would definitely be beyond my scope...I have played with launching, just for red light shoot-outs, but I'm not very proficient ..Never really concerned me..mainly because the car was not design to go straight, and the thrill of high speed maneuvering is far greater than a 1/4 mile...
About the only thing I can advise, would be to wait until the clutch wears, for a little more clutch travel from disengagement to engagement.. and the clutch stop mod along with the CDV delete to help you with launching..Or you could learn how to do it without the mods....But my best suggestion would be a trip down to the nearest road course learning rev matching, gear selection and good lines..... and not to concern yourself so much on launch...because drag racing(launching) is brutal on the drivetrain of any car...

Kicbax
07-26-2005, 07:52 AM
Yeah, I think I am gonna go and enroll in a driving course one of the weekends(Shhh don't tell anyone) to get a better feel for how everything outside the basic should be done optimally and smoothly. Thanks for all the advice.

Pinecone
07-27-2005, 03:08 PM
You should be putting the throttle back in as you re-engage the clutch. ANd it is not a lift off the throttle, it is lifting a bit to keep the revs from going to the rev limiter when you have the cluthc disengaged.

As for RPM, yes, if you shift at redline from 1st to 2nd, the revs will end up at about 5000 RPM, which is just about the torque peak. So while the curves don't cross, that is a good place to end up in the next gear, giving you maximum acceleration in 2nd.

I am home nad checked my gear-speed spreadsheet, and yes, in all gears, the E46 M3 needs to be shifted at redline to gain maximum acceleration over the entire speed range, although 5 - 6 is not a big deal as the spread is not too great from 5K on.

Kicbax
07-30-2005, 07:33 PM
Pinecone- Do you mean the actual redline, like around 8000(or higher) or do you mean right before the redline? I usually shift at 7500, right when the tach starts to hit the yellow/orange area when racing. Should I be bumping that up a few hundred? I did notice one day when I was off my shifting in first the car hit like 8000 and I think the rev limiter came on and my car kinda bogged down. Or perhaps you can tell me from your own experiences the very last place on the tach I can safely shift before my rev limiter comes on. Thanks

Pinecone
07-31-2005, 03:46 AM
If you graph torque delivered to the rear wheels versus speed, you will see the curves never cross. And the crossing point is where you shift for maximum acceleration.

Basically as you go up in revs, at some point the torque drops off, but you still have more torque to the rear wheels in a lower gear due to gearing mulitplying torque.

So the proper shift point is where the torque to the rear wheels in the lower gear drops below the torque delivered to the rear wheels in the higher gear. You use speed since this gives you the change in RPM due to gear changes.

In most cars, those curves cross somewhere before redline. But not on an E46 M3. So for maximum acceleration, you need to shift at or just before (7800- 7900RPM) redline. If you have an extended redline (Shark or siilar) you would shift in most gears above 8000 RPM, but you would need to grpah with the new torque curves, since they do change with software changes.

Same on the E36 M3. With stock redline most (if not all, I don't remember exactly) you need to shift at redline. With Shark or similar, you can actualy shift below the new redline in some gears.