Double Clutching

[ajames]

I don't mean to beat a dead horse, but i am not really asking about stuff pertaining to the huge heal-toe thread a while back.

this is actually about DOUBLE clutching ... as in when all is said and done, the clutch has been pressed TWICE ... not rev matching

I know the differences between the two ... full-out double-clutching and then just "rev matching" but which is more correct? i say more correct because i realize they both most likely work. i have always used double clutching and taught myself to do it that way ... i guess i did because there are no articles on "rev matching" on the internet ... only double clutching.

is there somethin better about allowing the clutch to be engaged in neutral while revving? doesn't this fully relieve any stress on the engine/drivetrain? i am not positive, but i assumed it was better to have the clutch out in neutral rather than have the car still in gear with the clutch simply pressed.

and btw, i don't buy the "it takes too much time" because if its done properly ... its rather fast ... faster that you would assume if you don't know how to do it.

sometimes, i have even taken to double-clutch as i up-shift as well. any benefits from that? i don't blip the throttle as there is no need whatsoever, but is it true that it also allows the engine to come down more easily from the higher rpm's when when shifting to the next gear?

does anyone actually double-clutch and not simply match rev's ... and can explain why to me?

thanks

alex

[Deloriant]

I believe people double clutch when they want to keep RPM high when shifting. Having the clutch fully engaged is not the same as being in neutral. Although I can't explain why, since I don't understand it, I just know it to be so. So when poeple upshift, they throw the clutch in again, rev their engine to keep rpm up, then drop back into the higher gear.

[whosurdaddy]

is there somethin better about allowing the clutch to be engaged in neutral while revving? doesn't this fully relieve any stress on the engine/drivetrain? i am not positive, but i assumed it was better to have the clutch out in neutral rather than have the car still in gear with the clutch simply pressed.

there wouldnt be and different if you have the tranny in gear or in neutral, either way if the clutch is in and your revving there not connected, so it shouldnt make a difference

[Kevin325i]

Well you do it if you don't have syncros that allow the input shaft spin as fast as the output shaft. Basically it's not needed and an extra headache to do on upshifts. It's also really not necesary on downshifts either unless you're in a race car wtih dog teeth and no syncros.

Yes it can be very quick, and in the proper hands even faster than the average "granny shift" but it's total bullshit unless you don't have a syncro.

One more thing, yes I have experience with double clutching. Only on a downshift though I never had to worry about upshifts. The syncro on 3rd in my jeep (2 lane passing gear as I like to call it) was shot for a downshift.

So either you had to shift it to 4 and hope that big ass hill would carry you by the car infront, or double clutch into 3rd, very annoying.

I don't know if I answered what you wanted to know however.... sorry if I didn't.

Kevin

[Deloriant]

Originally posted by whosurdaddy@Jul 27 2004, 09:14 PM


there wouldnt be and different if you have the tranny in gear or in neutral, either way if the clutch is in and your revving there not connected, so it shouldnt make a difference

There is a difference between being in neutral and having the clutch engaged. Holding the clutch in does wear it down.

[325isBaby]

Double clutching is only NEEDED on non-synchronized transmissions....which unless you are driving a 1950 model or a big-rig you have synchro's....the only thing you are doing by double clutchin a synchroed tranny is wearing out the clutch material twice as fast.