Engine Drivetrain 2nd Gen S Most liked posts in thread: Slipping the clutch?

I'm sure someone will correct me if I'm not 100% accurate...but...to me:

Slipping the clutch is when you slowly release the clutch when shifting instead of "dumping the clutch" which is to quickly release the clutch.

Slipping = easing the clutch.

 

Personally I always use the gearbox & engine braking when I drive my car, street or track, along with brakes. I do not see it as an abuse to the clutch. Yes you are correct brakes are cheaper. Now drag racing is something else entirely & a hard launch is usually how folks start an auto x run. I'd guess the first owner of mrminimmel's MINI cooked the clutch. With 17,000 miles on that clutch I'd be having MINI pay for the clutch.

 

Using the engine to slow a car down does not put any additional wear on the engine or clutch. The only time a clutch is experiencing wear is when it is engaging the flywheel. To minimize the wear you try to have the clutch fully engaged in as short a time as possible with as little difference in RPM's as possible (rev-matching/heel and toe).

The fastest way to wear out a clutch is to hold the car on a hill with the clutch instead of the brake. You should also resist the practice of resting your foot on the clutch while driving.

 

What year is your MINI? What was the mileage when you bought it?

 

Anytime the clutch is not fully engaged or fully released, it's slipping. So not only when you're engaging it to change gears or start from a stop, but just resting your toes on the pedal can be slipping it.

 

Again, someone will correct me if I'm not 100% correct, but...

Using the clutch to slow your car during autocross is a bad, bad, bad idea.

Brake pads/rotors are easier & less expensive to replace than clutches, flywheels, etc.

 

It's still less expensive to replace brakes/rotors than clutch/flywheel, etc.

 

Yikes, I have know people who do that. ut:

 

My mother used to get 25,000 miles out of a Morris Minor clutch because she could do this so well. Simply superb clutch control - but an awful practice.

Best clutch slipping was on old British motorbikes - close-ratio four-speed 'boxes meant the clutch had to be slipped to run at any speed below 20-30mph.

 

I'm surprised that BMW / MINI would continue to use delicate clutches and throw-out bearings. They need to knock the spec's up a notch or two on this mechanical tidbit. A plastic constructed throw-out bearing is inexcusable. What ever happened to the concept of continual improvements?
Yeah, I know.... everything costs something, but they also need to be a little concerned about developing a reputation for early clutch failures and finger pointing at "customer negligence" being the problem. After all, these are the same people they should hope will buy another MINI....

 

assuming you installed the os giken, how is it after a few months driving??

 

Even 'dumping' the clutch will let the clutch slip a bit, though a much shorter period of time than very slowly easing the clutch out from the same stop. Dumping the clutch is harder on the transmission (a more sudden/violent application of force through the transmission to the wheels), but is gentler on the wear of the clutch. IMHO, I'd rather burn a bit more of the clutch plate ($2000 repair) than cause excess wear on the transmission (could be $4000+). If we didn't need something to ease the transision from stopped to rolling, then why would we even have a clutch that is designed to slip and cushion the components from the crashing together of gears that would happen if it weren't there?

Technically, there is some additional wear on the clutch when you downshift. Even if you rev match perfectly, you are still incurring some wear on the throw-out bearing every time you press on the clutch.

That being said, I frequently downshift for steep inclines and when I'm at the track. A well executed and rev-matched downshift helps to slow the car a bit for a turn, but that shouldn't be the purpose of your downshift when at the track. The purpose is to get the shifting done earlier, while you are on a straighter path before the turn. You want to get the upset that will be done to the car's weight distribution done early, while you are still in a straight line, so you don't have to incur the sudden weight transfer of the downshift while you need all of the tire grip helping you to change direction. It also allows you to get on the gas earlier and to accelerate out of the turn sooner.

 

I wonder if there are defective clutches. I've got a friend in the Tar Heel club that has a 2009 (I think) and he had to replace the clutch at 15,000 miles.

 

Quite possibly defective clutches & throw-out bearings. My clutch was replaced at about 30,000 because the TO bearing was making a noise when the clutch was pushed to the floor along with a notchy feeling. My clutch did not slip. The dealer replaced the disc, pressure plate & TO bearing, but not the flywheel. So far so good.

My MINI is a 2006, but it seems the parts have not improved with the later builds. Maybe you JCW guys need to de-tune a bit. :lol: