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This question may have been posted, but.... what is the correct shifting rpm
for max acceleration. 6600 rpm for hp or 3800 rpm for torque?
 

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7000 RPMs, in each gear for max acceleration.

Max Horsepower is made at 6600 rpms but that dont' mean you shift there, keep going less gear changes the better the gears tq multipler is still greater in that lower gear than the next higher.
 

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The tachometer in most M5s lags in first gear, so you will hit the rev limiter if you try to go past 6600 rpm...in first gear, better plan to shift between 6200 and 6500 rpm. After first gear it seems you can go to 7000 before the rev limiter kicks in, but I have not done this yet...

P.S. The above refers to stock M5s...
 

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KevinM said:
The tachometer in most M5s lags in first gear, so you will hit the rev limiter if you try to go past 6600 rpm...in first gear, better plan to shift between 6200 and 6500 rpm. After first gear it seems you can go to 7000 before the rev limiter kicks in, but I have not done this yet...

P.S. The above refers to stock M5s...
I dont' quite understand why so many think the tach lags behind i have no problem hitting 6900 rpms and not smacking the rev limiter when shifting...all these shifting questions lately really make me wonder...thats beside the point but somthing i felt like saying anyway :)
 

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Jayson said:
I dont' quite understand why so many think the tach lags behind i have no problem hitting 6900 rpms and not smacking the rev limiter when shifting...all these shifting questions lately really make me wonder...thats beside the point but somthing i felt like saying anyway :)
Well, because it does, seemingly, in most M5s...I will hit the rev limiter at an indicated 6600 in first, a situation which is well known and was acknowledged by the driving instructors at the BMW driving school in SC. If yours does not, you are lucky.
 

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KevinM said:
Well, because it does, seemingly, in most M5s...I will hit the rev limiter at an indicated 6600 in first, a situation which is well known and was acknowledged by the driving instructors at the BMW driving school in SC. If yours does not, you are lucky.
It's not that I doubt it, it just seems so odd and so many other things people post about shifting, its all well and good to find the right answer i dont begrudge them that. But in this case I test drove an M5 before buying mine, then of course mine, then the one at the M school and none of them had this situation...and nobody there said anything close to this.
 

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The 2000 and 2001 model year press vehicles we've tested at work (i work at edmunds) have had sluggish tachs. The 2002 model we tested was slow in first gear and we did not receive a tester for 2003. I have interacted with several people who have said that their tachs swing slower than the engine revs - and some had mentioned that the problem was "addressed" in 2002 and "eliminated" for 2003.

As for shifting points, I think once the needle swings up to 6500, generally it's time to shift. I agree with KevinM's statement in that by the time the needle's at 6800, the rev limiter is barking for the next gear.

-Matt
 

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matt310 said:
The 2000 and 2001 model year press vehicles we've tested at work (i work at edmunds)
sweet line of work!! my dream job would be automotive journalism.. unfortunately I can't write journalistically.. and edmunds is a great resource!
 

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Jayson said:
It's not that I doubt it, it just seems so odd and so many other things people post about shifting, its all well and good to find the right answer i dont begrudge them that. But in this case I test drove an M5 before buying mine, then of course mine, then the one at the M school and none of them had this situation...and nobody there said anything close to this.
I found the lots of similar comments when I did a search using the words "rev limiter"...I did this to see if what I was experiencing was normal or if I should have it looked at.

After I read all the posts, I came away thinking it was normal, but I still may have it looked at.
 

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KevinM said:
I found the lots of similar comments when I did a search using the words "rev limiter"...I did this to see if what I was experiencing was normal or if I should have it looked at.

After I read all the posts, I came away thinking it was normal, but I still may have it looked at.

If this did happen as stated above for just years 2000 - up to 2002, then they know how to address it, may take a fight but if somebody has this then make um fix it, cuz thats not right.
 

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2003 here. Tach lags ~500rpm in 1st, less in 2nd, no lag by 3rd gear. 1/4-mile times were best for me when shifting at 6500rpm (12.87 stock).

The correct answer is..., whatever the stopwatch says is best for your setup. Each car/driver combo will be different. Testing will reveal what is best for you.


:byebye:
 

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Anzir said:
sweet line of work!! my dream job would be automotive journalism.. unfortunately I can't write journalistically.. and edmunds is a great resource!
Thank you, that's always nice to hear. My degree field is journalism/photojournalism and I am exactly where I wanted to be in the auto industry - at an unbiased, privately owned media information company.

-Matt
 

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FYI - in order to determine the best shift point, you need to know the torque at the rear wheels pre- and post-shift. This is easy enough - just multiply engine torque by gear ratio and rear-end ratio. In our cars, you have more rear-wheel torque at redline in the lower gear than you will once you shift. (If your rev limiter is raised, however, that MIGHT not be the case.)

I put an excel file up a long time ago that uses the factory claims for torque vs. RPM and maps all this out - download it in an instant here.
 

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Along the same lines, I find that if I'm holding WOT up to the point of shifting, many times I get a slight over-rev when shifting. Especially difficult when going 1-2, easier in the higher gears.

I've been working on backing off the throttle prior to shifting, but there's a fine line between backing off just enough and too much...and if I back off too much, I'm losing speed and end up at too low an rpm for the next gear, etc., etc...

Any recommendations on a good technique for this?

By the way, I agree on on the amount the tacho is off. I get redline about 6800 in first, 7100 in second and full redline in 3rd (Powerchipped, with redline at 7400)

:cheers:
 

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Go with a software upgrade (PowerChip) that will remove the rev limiter, top speed limiter, and improve throttle responce! No problems
:1:
 

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Go with a software upgrade (PowerChip) that will remove the rev limiter, top speed limiter, and improve throttle responce! No problems
You mean raise the rev limiter right, not completely remove it? I would be hesitant to raise the limiter too much, as it's an accident waiting to happen with your warranty incase of an engine problem. If you must raise the limiter, 7300RPM seems to be a good point, as Dinan's software raises it to this point also.

Travis
 

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M5Kid said:
I would be hesitant to raise the limiter too much, as it's an accident waiting to happen with your warranty incase of an engine problem. If you must raise the limiter, 7300RPM seems to be a good point, as Dinan's software raises it to this point also.

Travis
I had the rev limit at 7650 for a while. On the dyno, power did not fall off until past 7300. I set it back down for warranty issues also.
Regards,
Jerry
 

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M5Kid said:
You mean raise the rev limiter right, not completely remove it?
Travis
I will have to check this with PowerChip. I thought their mod removed the limiter. I have not bumped against it???
 

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How far up have you been in the revs?

The furthest I have ever heard of Powerchip raising the rev limiter was on MAH's M5, and they set it to 8,000RPM.

Travis
 
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