What exactly burns the clutch on an m6?

[Jcobra]

Originally Posted by nhra stocker

This is burning up a clutch!

Ha ha, more money than brains.

[Shu71]

Actually if you press the clutch pedal to the floor and rev it up the disk is still making some contact with the flywheel and the pressure plate so to some extent it is wearing on the clutch disk friction material but not enough pressure to be tremendously measurable. Riding or using the clutch more than needed does wear out more than just the clutch disk, it weakens the pressure plates and wears on the throwout bearing. Why the need to force downshifts coming up to a red light? Clutch, shift to neutral, release clutch pedal, coast. If the light changes and you are ready to move again, learn your gear ratio's and feel so you understand what gear to put it back in to drive away with traffic. At a stop light for the longevity of the clutch, pressure plate and throw out bearing, sit in nuetral with your foot off the pedal, when light changes, clutch, put it in gear and roll away.

[motorswin]

hey not sure if this is anything like you have been talking about but the other day I was driving and i held in the clutch and revved it up and after that my clutch pedal seemed to "lighten up". it was wierd, almost like it was weak.

[BlkThndr66]

What you're currently doing is called double-clutching. Old cars used to have mechanics that required this sequence. There is no need to shift into neutral and let the clutch out then clutch in and pick the gear. Just clutch-in, rev match, and ease clutch out. I only do this maybe down to 3rd gear, or 2nd if Im downtown. I never shift back into 1st unless Im down to like 5mph and the light goes green.

Ive also always heard that less time on the clutch is best. If you don't need the clutch in; get off it! Sitting at a light with the clutch depressed and in 1st gear is pointless and doesn't do 'damage' but it is unnecessary wear. I can't believe my mother had been driving with the clutch always in if not moving and in gear. She also would never rev-match! Ugh, seeing her pop that clutch from 1500 to 3k is just like nails on a chalkboard to me.... ugh I can actually hear the clutch and flywheel screaming ! AHHH !!

[BlkThndr66]

Originally Posted by motorswin

hey not sure if this is anything like you have been talking about but the other day I was driving and i held in the clutch and revved it up and after that my clutch pedal seemed to "lighten up". it was wierd, almost like it was weak.

Do you press the pedal to the floor? Every. Single. Time? Cuz you should. I know it's hydraulic, but always always Always put the clutch to the floor. If not; I'd be kinda worried, is it still a 'weak' pedal?

[MLL67RSSS]

Thread jack alert!!!!!

You know back in the olden days when I took driver's ed (1975) I was taught you should keep the car in gear when sitting at a stop light. If you're rear-end by some inattentive driver it can incapacitate you to the degree your are unable to hold the brake and there will be nothing to keep the car from rolling forward, at best into the car in front of you, at worst into the intersection where you could be T-boned by cross traffic. Also when first in line waiting for traffic to clear to make a left turn, some people will turn the wheels anticipating their turn, if you're rear-ended then you could possibly roll/turn into the oncoming traffic.
Now I'm just throwing that out there for your amusement. You all should do what you prefer and are comfortable with. I will say I adopted that method when driving manuals. I had a little 4 spd manual Chevette as a DD for 16 or 17 years and 196K miles and never had any issuses with the clutch bearings/springs or had it replaced.

[Russell James]

Exactly. I've been driving manuals for decades, always leave it in gear - clutch in at the light.

With the clutch pedal in - there is zero clutch wear.

Another fact - with the clutch pedal pushed in, the spinning clutch is actually cooling. If you were in neutral with the clutch out, the clutch is sitting against the flywheel soaking in the heat from the flywheel.

When hot lapping at the strip and the clutch is too hot - how do you cool it down? Push the clutch in and rev the engine a bit for a few minutes to get some air circulating in there. If you just let it sit there in the lanes after hot lapping with a red hot flywheel and the clutch up against it - its going to stay hot for a long time and probably slip on the next run if it is overheated.

[Johnnyma45]

One thing also, a brand new car/clutch will take a bit of mileage to wear in. So if anyone's driving manually for the first time, it will get better over time. I usually don't shift with the pedal to the floor...learned on an RX-8 where the shift point was so precise, it was either perfect smooth or neck jerking. Had to modulate the clutch perfectly, so going to the floor seemed like a waste of effort.

[Shu71]

If you can't hold the brake in the case of a rear end you aren't going to be able to hold the clutch either, so you will dump the clutch and lurch forward anyway.

When the clutch is pushed in you are in fact wearing on parts. The disk is slipping around against the flywheel just like your brake pads slide against your rotors when you are not on the brakes. You are also wearing on the pressure plates clamping pressure. You are also wearing on the throwout bearing having pressure against it like that. Granted at the strip you do push the clutch in to cool it down, most street cars under daily driving are not heat soaking the clutch like a drag car. If they are the clutch isn't going to last that long anyway because these are not racing clutches which are built to withstand that sort of abuse. Obviously we all have a different opinion on this and I'm sure everyone has their own historical results of one method or the other so do what you are comfortable doing. I'll let mine idle at lights out of gear

[Russell James]

Not really, the slight variation in rotor surface paralelism pushes the pads back off the surface. Any slight drag left is pretty meaningless. Tow a car across country behind a motorhome without touching the brakes, I'd bet your pad thickness at the end of that trip is pretty much the same as when you left.

Brakes and clutches wear when they are being applied. When a clutch is slipping excessively is what burns it - like the driver's ed student trying to learn how to start on a hill. On the other hand, push the clutch in and pin the throttle against the rev limiter - smell anything burning? No.

If your clutch was dragging/slipping against the flywheel when pushed in, the trans would grind like crazy when you tried to put it in gear. When that does happen, that is a sign something is wrong and the clutch is not fully releasing. Remember the V6 bulletin for the pressure plate bolts backing off? People were grinding gears and difficulty getting it into first. Because when those bolts back off you lose the ability to create a gap between the flywheel/clutch/pressure plate.

[Russ]

Down shifting;
Ive never heard of or seen someone actually revving the engine to sync to the appropriate gear,or "rev match".
When I down shift (approaching a stop and say Im in 5th) I brake a little, if needed, until the rpms come down to the range for fourth on their own. the same to 3rd,2nd.
As your slowing the rpms will naturally drop, with foot out of the gas ofcourse. So why would you need rev match when they drop on thier own.

Oh and just for qualification, Ive been driving manuals for over 20yrs now. Man, I really hope someone doesnt tell me Ive been doing wrong for 20 yrs. Lol.

[C586]

Originally Posted by Russ

Down shifting;
Ive never heard of or seen someone actually revving the engine to sync to the appropriate gear,or "rev match".
When I down shift (approaching a stop and say Im in 5th) I brake a little, if needed, until the rpms come down to the range for fourth on their own. the same to 3rd,2nd.
As your slowing the rpms will naturally drop, with foot out of the gas ofcourse. So why would you need rev match when they drop on thier own.

Oh and just for qualification, Ive been driving manuals for over 20yrs now. Man, I really hope someone doesnt tell me Ive been doing wrong for 20 yrs. Lol.

You have been doing it wrong for 20 years. You rev the engine to match engine speed to output shaft speed. On the track this is done while braking so you don't waste time shifting when you come out of the corner. Some do it on the street because they can. The way your doing it isn't wrong just not right. The way your doing it you should just come to a stop and go to first or 2nd if u get the green before your completely stopped.

[BigCarrot]

I down shift to slow down but never let the rpm jump above 2k and never down shift below 3rd. I've never tried rev matching to down shift (just seemed like a waste of gas and I figure going from 1k to 1.5-2k rpm isn't putting too much strain on anything).

[MLL67RSSS]

Originally Posted by Shu71

If you can't hold the brake in the case of a rear end you aren't going to be able to hold the clutch either, so you will dump the clutch and lurch forward anyway.

Exactly! If you dump the clutch while sitting idling the car stalls and since it's in gear, stops moving/rolling. If out of gear and you're hit hard enough to incapacitate and/or disorient you, your car can roll and keep rolling until you either hit something to stop it, or you gather your wits enough to apply the brakes if possible, but by then it could be too late.

Oh and BTW double clutching was a practice from some time ago when some cars and a lot of trucks didn't have syncros in lower gears, or on any gears in some cases. Double clutching would aid in getting the gears to mesh and engage easier.

http://en.wikipedia.org/wiki/Double_clutch