what is it REALLY used for? I recently destroyed my second gear synchro and I can't just simply shift into the gear, down shift or upshift, so I told my dad and he suggested double clutching... I've been doing it and I haven't grinded the gear since... but I just wanted to know why else would you double clutch?

 

Double clutching is a thing of the past - fast n furious style BS

 

There are several pretty good explanations at the following links:

What is 'double clutching' ??

Heel Toe Shifting (See last paragraph of first post.)

HEEL & TOE AND DOUBLE CLUTCH

You may be able to find more threads on this subject using the Forum search feature. Hope this helps!

 

You need to double clutch when you have no synchro's, ie...some larger older style trucks...but not much anythign else anymore.

 

granny shift .. not double clutchin like should.

hahah .. he's dumb.


in this case, double clutching would work for you as you no longer have a second gear snycho.

 

I crunched my second gear synchro when my son got next to me at a stoplight with his GTI VR6 6spd Golf, that little sucker launches pretty good, anyways, in my exuberuance to make she he didn't get one over on my, I missed 2nd and crunch. Ouch, good news it still shifts okay.

Tino

 

Great links, thanks Jim!

 

Double clutching is becoming a lost art. However, if you drive an old car that is pre-synchro, you will learn that art in short order. I drove a 1928 Chevy (all original, including mechanical brakes!). Wow! We don't know how good we have it these days, I think everyone should have an opportunity to drive one of these old relics just once.

 

Double clutching makes all downshifting smoother, synchros or not.

Saves wear and tear on transmission parts. If you aren't doing it you are just an amateur, usually best known as someone who "blips" the throttle.

There is no substitute for actually knowing how to drive a standard transmission. A lot of beginners here on the forum.

 

Hmm... Are you refering to HT downshifting as an "amature" move? Forgive this "beginner" for asking you to explain how double clutching a modern sports car makes down shifting any smoother? And specifically which transmission parts are saved.

 

thanks for all the help guys! well, my second gear synchro isn't completely gone, OCCASIONALLY it will slip in nice and easy with no grinding, but when it does grind, it makes it worse, and I didn't want my car to get messed up, specially a transmission, not cheap. Plus, grinding so often makes me afraid to shift... so I had to do something! The double clutching works and thats all the proof I need, but I now see why... thanks guys!

 

sounds to me that he is describing rev matching... but i could be wrong

 

It's good for driving schoolbuses.

 

Drove Formula V for a couple of years back in the mid-70's (VW Powered Formula Car) and had to double-clutch between 1 - 2 & 2 -3 because there was no reverse gear in the car and 2nd and reverse used the same gearing.
It was difficult getting used to because you had to heal and toe the gas/brake to keep the revs up on a downshift.
If you blow your syncs on a M6 for 2nd I think it's tied to reverse too, but I'm not sure.

Regards

Jim

Don't forget if you party over the holidays to use a Designated Driver if you partake to much. We want you back in good shape after the New Years.

 

"Rev-matching refers to matching the engine speed to the transmission input speed before re-engaging the clutch. Good for downshifting into a corner. In a hard corner, the suspension needs to be stable and the tires need to be loaded so that all of their traction is being used to generate cornering force. If the engine is at a different speed than the transmission input when the clutch is re-engaged, this will generate a force on the driveline that will upset the stability of the suspension and will cause the tires to exceed their traction capability if the corner is being taken near the limit.

It *is* necessary to rev-match if a corner is to be taken near the limit. It isn't necessary for slower corners, but it will make them smoother.

Double clutching is a technique for rev-matching the transmission's *intermediate shaft* to the output gear that is to be selected. This is a function that is normally handled automatically by the transmission's synchro-mesh gears (or synchro's). It is useful to double clutch for extreme gear changes, for older transmissions with worn synchro's, or simply to save wear on the synchro's. It's also an entertaining thing to do. "






"Double clutching" has nothing to do with so-called "amatuers" or "Beginners" as described by ztheusa when talking about a modern sports car such as the C5 and IMO unless you have a need to such as you seem to or are going from 5th to 2nd for some odd reason, it is a waste of time.

 

I've been to two racing schools and they taught us how to double clutch just to appreciate the fact that we could heal & toe without it. But it is the same thing... the only difference being that you blip the throttle in neutral with the clutch out. Modern transmissions allow this step the be skipped. I can heal & toe and match the revs just fine... you can bearly tell that I blipped the throttle at all or changed gears.

 

 

Theres a lot of misinformed people on this forum.

 

 

Despite my five driving schools (all in non-synchro gearboxes which did require toe-heel downshifting but did not require double clutch downshifting), 9 DE days and 24+ SCCA races... all on the original tranny and diff, I guess I'll stay a happy "amateur".