wfenris

I have never raced a standard only auto muscle cars. So my question is whats exacally is double clutching because i have been told a couple different things, and is it worth it to do it while racing, what are the benifets ect.......

Juan

iTrader: (28)

double clutching is effective only when you granny shift.

wfenris

well what excally does it do ?

peejay

double clutching is done primarily on downshifts, although I do it all the time on upshifts 'cos of worn-out synchros. Double-clutching is necessary for non-synchro trannies, too.

Here's what you do...

Clutch in
Shift to neutral
Clutch out
Blip throttle to match the revs to the next gear you'll be in (no blip needed when double-clutching an upshift)
Clutch in
Shift to next gear
Clutch out

A well done double-clutch takes less than a second. if you're good at rev matching, you don't need to use the clutch at all, but it doesn't necessarily mean you shift faster. (My first 5-speed car had a seriously low brake pedal, so I'd use the left foot to brake and I'd downshift without the clutch) If you're not using the clutch, it works exactly the same way, just delete all of the clutching parts. But you have to get the revs exactly right for it to work.

Double-clutching is generally only for endurance road racing where you have non-synchro trannies and/or transmission life is more important than the couple tenths of a second you lose per lap. Although I have been known to double-clutch upshifts at the dragstrip 'cos my tranny was so messed up it was the only way it'd go into gear Definitely not the fast way to shift.

Erik

unless you double clutch you'll never beat Vin Diesel...hahahaha

a lot of truckers sometimes double clutch...or use no clutch at all...i used to have a ford bronco and you could pull it outta gear, give it some gas to generally match the revs...and the shifter would slip right into the next gear without using the clutch

RETed

It's only for non-synchromesh transmissions; you don't really need to do it for most modern transmissions with synchros.



-Ted

Bambam7

It's easy to do that on the 7 too... though a little more presicion required than on my old jeep....
I never use the clutch when slowing down- Just force of habit- I pull it out of gear JUST as I let off the gas, and there is no forwards or backwards tension on the tranny... just been doing it for so long I don't even know I'm doing it.
It started when I had a jeep with a leaky clutch slave... I tried to stretch the 20 or so times I could depress the clutch before the resivoir would empty as much as I could! Now it's juts ofrce of habit, years later... wierd.

ReZ311

iTrader: (4)

You don't need to double clutch. That is what syncros are for. Use the heel toe method when apporaching corners.

Good double clutching explanation peejay. =)

Angel Guard Racing Team

Double clutching is movie BS and amateur fantasy BS. The way to go is to never lift the foot off the gas pedal hit the cluth and throw that gear in like lightning. Be careful with 3rd gear... By the time you are done double clutching you will have any CRX pass you by.

peejay

Sure, if you're DRAG racing...

BTW "throw the gear in like lightning" is exactly how to stuff a transmission, bending shift forks and generally missing shifts... shift quickly but not forcefully!

speedjw

Peejay, very thorough explanation of double clutching.

If I had anything to add, it might be that double clutching on downshifts is beneficial to all transmissions. By double clutching you are effectively no using your synchros. As we all know, the synchros are the first components to wear in our transmissions.

It also allows the engine a few tenths of a second more to accelerate to the necessary rpm for the next lower gear, generally giving you a little cleaner downshift.

You'll find that almost anyone who calls himself an ethusiast will double clutch their downshifts. Plus if you ever decide you want to try driving something real, without a synchromesh transmission, its a good thing to know.

ReZ311

iTrader: (4)

Angel Guard Racing Team????

No. Heel toe method. Don't keep yoru foot on the gas.

Gene

iTrader: (1)

You really ought not to be heel toeing in a drag race. Ideally, you should stay off the brakes alltogether.

peejay

Some us like to drift around the 180 degree corner leading to the timeslip shack/return road (note: never tried it, pretty certain they'll kick you out for it - but when you have 50-60psi in the front tires, 18psi in the rears, and the back tires are very hot, drifting is inevitable )

BTW I don't mean to dis AGRT... I just see too many people who THINK they can shift worth a s*** and all they're doing is killing their trannies and not actually shifting any faster than your aunt Mabel in her 10 year old Tercel.

Icemark

Sounds like someone that has never had to rebuild a tranny...

I always double clutch down shifts to 2nd and 1st, and sometimes 3rd (depending on what and how I am driving). I'd rather have my syncros working than worn for up shifts.

ReZ311

iTrader: (4)

You are hearing too many sounds then grannyshifter.

amemiya

that is the FUNIEST thing I have ever ever heared.

amemiya

rx7 trannys represent everything that sucks.

Gene

iTrader: (1)

yeah my tranny is shot to simthereens, so I double clutch every time (esp on upshift, you can barely get it in otherwise)

Mykl

Yeah, try getting any transmission to go into first at over 20 mph without double clutching.

My WRX is brand new and even it doesn't like it.

I double clutch all the time in the FC, it's necessary since the syncros are worn out, but I only double clutch in the WRX when I'm not in a hurry. When I'm hustling around I just match revs and heel-toe.

peejay

Mykl you got a WRX?

Subaru trannies are weird... they build them very tight, and they don't break in until after about 20k. Of course they don't wear out until like 300k, either...

Merovign

For tranny life and faster shifts than the above method, skip the two center clutch actions and modulate (not blip) the throttle with the clutch in, thusly:

clutch in
don't lift from throttle (unless at full throttle)
let revs rise as you move the shifter
let clutch out in new gear

With practice, you can have the engine "ready" for the new gear, thus easing wear on both the tranny and the clutch. The revs should not "jump" when you enter the new gear.

One definition of "double-clutch" is that "clutching" can be technique as well as hardware - you use both at the same time and there's less wear on the hardware.

And there are many cars you can shift without using the clutch. Try it gently sometime and see.

I double-clutch with every upshift, it's so easy and quick... downshifts take more time and thus I don't always catch it right... in drag racing, you don't downshift.

A lot of people think a transmission sucks when it blows up when they powershift it all the time. ANY transmission will blow up under those conditions. Powershift = full-throttle clutchless shifts. Bent shift forks, actuators, blown synchros, stripped gears. If you don't want to use the clutch, buy an auto.

LLADNAR

you know i like the Fast and the Furious,,BUT,,it has ruined an entire generation as far as the double clutching thing goes,,i get so tired of telling people they are retarded for thinking that is a performance term,

tmak26b

Subarus got some clunky trannys, worse than the FC i might add