no, there's no need to double clutch at all on a modern transmission. basically, to keep it simple, back in the day you had to double clutch because the gears were all seperate. if you were in first gear, when you shifted to 2nd, you were physically disconnecting the gears, and putting the next 2 sets of gears together. if the engine and transmission weren't spinning at the same speed, the teeth would not match up and grind. with modern trannys, and what's called synchros, the gears are always together. so you can just hit the clutch, shift, and let the clutch out. in other words, in new trannies the gears never actually disconnect from each other like they used to.

if you were to go in first, shift fast to 2nd, and dump the clutch, the car would jump forwards and give a nasty lurch. that's because the engine and tranny are not spinning at the same speed, and all of a sudden they're forced to go the same speed. however, the gears won't grind. before synchros were used, you oouldn't do that, and that's why you had to double clutch. hope that makes sense.

 

the only vehicle i double clutch on in my buddy's 63 landrover because it shifts way better if you do. and **** downshifting...so you can guess my opinion on double clutching...

 

lol thanks for all your input

 

Good thread. I started double clutching (or rpm matching, whatever you call it) when downshifting. It's worked out much better, much smoother. thanks.

 

rev matching is not the same as double clutching. you SHOULD be rev-matching on shifts, unless you like the violent lurches caused by not rev matching.

 

It doesn't affect the synchronizers at all. When you rev match, the clutch is disengaged, therefor changes in engine speed will not affect the gearbox.

 

What are the benefits of double clutching?
Letting everyone know you learnt how to drive watching F&F movies

its pointless in a modern day car.

 

i think he meant as opposed to down shifting and dumping the clutch.

 

Still doesn't affect synchronizers in any way. They only do their job on gear changes, not clutch engagement/disengagment.

 

Well lets just say my buddy that drives a rustang... his version of double clutching-
1-Pull out of gear into neutral
2-Push in clutch
3-Select gear
4-Drop clutch and give it gas

Obviously he is an idiot... he does drive a mustang.. lol. But anyways I rev-match all the time, but never really see the need in double clutching.

later

 

But 2 gears and the dogteeth are still spinning at engine rpm or lower so it does help with them locking in with syncros. It is not needed but there is no real reason not to. If you do it do it, if not dont, it doesnt really do anything unless the tranny is already slipping dogteeth.

Oh and D4 I believe you were refering to the term "constant mesh."

 

hmm, maybe some one needs to post some vids of this phenomenon.

found a video on youtube double clutching, you guys tell me
doubleclutching

 

tell you what? he is double clutching....

and theres still no point doing it in a street car.

 

The clutch is disengaged, changes in engine speed will not affect them.