bobatimez

please help. when going all out and shifting near redline, what is the correct procedure? let off gas, press clutch, shift, try to rev match the release clutch? what causes the clutc to burn? how to avoid it and what are some of the key points to keeping the tranny/clutch healthy? thank you all.

RazorV3

rev matching is very important. although newer transmissions are equipped with synchros(which match up the transmission and engine speed), its still a good idea to rev match between upshifting/downshifting. if the transmission and engine(flywheel) are spinning at the same speed, there is minimal clutch slippage and therefore will extend the life of your clutch. slippage is caused when the 2 parts are not spinning at the same speed(clutch and flywheel), the clutch will have to play "catchup" with the engine to match up to its speed. this will cause the clutch to slip and wear it down if there is a big difference between engine and tranny speed.

another way a clutch can slip is anytime you have the clutch partially engaged(like resting your foot on the clutch pedal, very bad aka "riding the clutch"). the reason this is bad is because the clutch isn't fully engaged and has minimal contact with the flywheel.

when shifting, try to either have the pedal fully engaged or fully disengaged. anything in between is bad and minimizing the time in this "zone" is always a good thing. in other words, make your shifts quick and effective.

i hope you understood all that.



EDIT: i found a great link that has a good animation and backs up everything i said. http://auto.howstuffworks.com/clutch3.htm

exsilio

Words to live by.

xviper

Boba, are you talking about upshifting or downshifting?
If you are downshifting, then yes, you need to rev match to make things work more smoothly. If you are upshifting, you already rev match by simply taking your foot off the gas and letting the revs drop to where they will match the next gear's output speed. If you are "giving 'er", like in racing (at the drag strip of course ), you need to do everything REALLY fast. Thinking about each individual step and doing each individual step will cause you to be left far, far behind.
When driving "briskly" all of the following can be done in a split second:

At the same instant ----- begin to release gas, begin to push on clutch, begin to move shifter. You can actually take it OUT of any gear you're in without having to have the clutch on the floor first. This is important to know, especially if you are "in a hurry".
NOW, by the time your gas is let off but the rpm still not quite dropped too low, your clutch should be not quite to the floor, your stick should be about in the midway point of its journey to the next gear. THEN, the instant your clutch touches the floor is when your shifter should be just entering the next gear (and then in the next gear). AT THIS POINT, you should be releasing your clutch about as fast as you can take your foot off it AND beginning to apply heavy throttle. REMEMBER, all this stuff happens in less than a second if you are truly trying to GO QUICK!
I have a vid from inside the cabin of me doing a series of these sorts of shifts that shows you the sequence and the time frame involved. If you are interested, PM me your email address and I'll send it to you. It will be about 4MB big, so your email server must be able to handle one that size.

WARNING: You need to practice this sort of thing at a slower pace or you could break something really expensive!!!!! If you don't do it right, you will grind like crazy.

Where you will burn your clutch (slip it badly), is when you apply the heavy throttle too soon before you have released your clutch at the tail end of the shift.