Don't try this at home!!! - The Unofficial BMW M5 Messageboard (m5board.com)

M PWR · 14th December 2001, 02:56

To all of you who read the newest Car and Driver issue that talks about the cabrio E46 M3 don't do what I did!!!

I switched off traction control activated sport mode 4500rpms dumped the clutch!!! The car car accelrated slowly but the rpm went in less that a sec to 8000, I shifted into second sofast and again the rpm was at 8000 but the car began moving fairly quickly. At that instant I didn't know what was going on!?

Wheather I had a wheelspin all through 1st&2nd gear or the clutch was slipping??? Anyways I tried it twice. In notime my car was filled with burnt clutch smell

My clutch when I press it made a small sqeaky sound and was softer than before now I was really

I went back home and slept!!! The next day I started the car the clutch was not quite okay but much better than it was!! But I can smellthe burnt clutch in my till the next night!!! I think and yes I did burn 60% or more of my clutch on that stupid take off, and at that time I think my clutch was very hot and thats why it was softer when I pressed it. Guys, DON'T BELIVE WHAT YOU READ!!!

belive me youdon't want to experiance what I did!!

M PWR

teezm3 · 14th December 2001, 23:47

Very bad behaviour M PWR

... I didn't know it would burn so much of the clutch at 4500. Anyway most of the tests by the car magazines say 1200-2000 is a good lauch rpm range.

So are you getting your clutch replaced?

M PWR · 15th December 2001, 15:02

Well yeah 4500rpm launchs is alot of power for clutches to lock, but I thought I would give it a try since Car&Driver did. Didn't realize exactly what would happen but it happened

I heard alot of M5 drivers complain about clutch slippage. I think that the stock clutch can't handle the power and torque that the car has, many are thinking of replacing it with after market heavy duty /racing clutches. I hope also thats not the case for M3s but never know so far I didn't need to. Well I have a appointment for replacing it late January.

M PWR

M PWR · 15th December 2001, 15:07

Well yeah 4500rpm launchs is alot for the clutch to handle(lock). But Car&Driver did it thought I would give it a try not knowing exactly what will happen next. Alot of M5 drivers complain about clutch slippage. I think thats because the stock clutch can't handle the power and torqe the M5 has. Many are thinking of replacing it with aftermarket heavy duty/ racing clutches. I never saw anyone yet complain about E46M3 clutches but hope not the same case for us too. Well I have an appointment for late January.

M PWR

johann · 15th December 2001, 18:13

Jetboy,

I do agree that the M5 clutch is not weak but I would say it's pretty sensitive and there is very little room for driver mistakes.

As for the E46 M3 the clutch seems to take a little abuse with a smile.

But I guess letting it slip too much at 4500rpm is a little to much even for the M3 clutch. However there is no problem using 4500rpm and just sidestep the clutch at least not for the clutch. The tires will spin a lot and the drive train may wear out prematurely if you do that often

M PWR,
I guess that C&D were discussing launching at or close to max torque. Maybe you can do that once or twice but you really have to be fast with the clutch but still not to fast otherwise you'll end up with a burned clutch or a sever wheelspin. Is that what C&D were trying to accomplish?

I know the SMG II uses 3500 when you use the launch control and then regulate or more correct minimize wheel spin with the clutch. That is very effective but for a quick launch but very tough on your clutch. Therefore you can only use the launch control a specific number of times and the car will also prevent use of several "launch control launches" in a row before a certain cool down time have extended.

Cheers,
/Johan

JetBoy · 15th December 2001, 18:24

Quote:

Originally posted by M PWR
I heard alot of M5 drivers complain about clutch slippage. I think that the stock clutch can't handle the power and torque that the car has

Well, If you drive that way any clucth won't handle the power. You are going to burn it again and again....

I don't think the stock M5 clucth is weak, I know several good drivers who own M5s and never happened that to them !! Of course if you have been abusing the car, for example what you did or starting the car in 2 nd or changing the gears without pressing the clucth all the way or reving hard the car in cold etc etc sure you are going to burn the clucth. It is very easy to flame Bmw saying that their clucth is weak.

No offense intended. Just my opinion.

M PWR · 16th December 2001, 14:38

Johan,

hehehe , what the hell was C&D thinking of doing to our cars!!
Johan I did it twice, belive me I was so fast dumping the clutch. Belive me , I smoked a 00M5 that had Kelleners exhaust system, Dinan chip, UUC short shift and my M3 was bone stock. But I managed to be ahead of him by one car length until 4th gear 120mph after that the M5 was passing me with momentum

You can ask him too he is registered on the web (M5ER). Wow SMGII 3500rpm lock thats really phat!! But even at that range of RPM you get wheelspin, I belive a good launch is 1500-2000. What about you how do you launch your car?

M PWR

johann · 16th December 2001, 16:23

M PWR,

3500 will give you wheelspin but the SMG II uses the clutch to regulate wheelspin, i.e. slips the clutch.

I use low rpms 1000-1400, otherwise I get wheelspin unless the road is absolutely smooth. You can ask Gustav if it works.

Cheers,
/Johan

JohnH · 16th December 2001, 16:32

I agree with Johan and tend to get the best starts 1000-1500 revs. Part of the problem is that the M3 revs so quickly that if you start off at too higher revs not only does it induce wheelspin but you hit the limiter in no time which then screws you completely. From 1000ish you seem to have far more control and time and without all the smoke and wheel spinning.