[Azrael]

It's been quiet on the forums. Too quiet.

That's why I'm stirring things up by asking those who may (or may not) know the idea behind double clutching. From what I understand, it's to get the engine rpms to a level matching the driveshaft for the gear, so the dog teeth line up properly. I don't see how that will speed up shifting in todays engines, given the inclusion of synchronizers. Help me out.

My knowledge on the subject courtesy of www.howstuffworks.com

 

[lo bux racer]

Double clutching saves wear on the synchros. The idea is to match the transmission input shaft speed to the output shaft speed. You can use the synchro to do this or you can pull the transmission out of gear, release the clutch in neutral, match rpm to road speed, then clutch again and shift into gear.

With modern transmissions it's a waste of time and effort IMHO. Besides, synchros are pretty cheap and I do all my own work. Even if I didn't I wouldn't bother double clutching.

 

[Fast Eddie]

Heel & toe is easier..........it just takes practice.

Reference (downshifting 101)

 

[JZA70]

i <3 heel toe shifting

 

[zoltiz]

Originally posted by JZA70@Dec 25 2004, 10:45 AM
i <3 heel toe shifting

And when do you use it in day-to-day driving?

 

[thunder sloth]

Were you granny shifting when you thought of this thread?

 

[Azrael]

Yes I was...I was driving down the road in my tC and I attempted to double clutch. It took me about 10 seconds to accomplish it.
What's heel toe shifting?

 

[lo bux racer]

Heel/toe is a technique to brake and match engine speed at the same time. The ball of your right foot is on the brake, with your heel on the throttle to allow you to downshift, match engine speed, and brake all at the same time. It's one of the basic skills you need for road racing.

 

[lo bux racer]

Here's a how to for heel/toe and double clutching.

 

[Fast Eddie]

What he said.

 

[Beantowntc]

ok i just want to make sure i understand the rev matching thing, when i downshift i put the lever in neutral take my foot completely off the clutch, blip the throttle then put the car in the lower gear?? is it ok for me to put the knob in neutral and blip the throttle while my foot still has the clutch depressed??

 

[Azrael]

No, because if the clutch is still depressed you will not move the layshaft or the gears on the driveshaft. Nothing will spin so the revs will not match.

 

[iGod]

i had to double clutch in my 46 chevy half ton truck. 3 speed non synchro. double clutch to go up a gear, and virtually impossible to downshift.


heel-toe just kinda always made sense to me - my old man taught me that when i first started driving.

 

[We11Spring]

Is it just me or is the gas/break placement on the tC a pain in the ass when it comes to heel/toe shifting? It really annoys me that I can't do it comfortably on the tC. I catch myself missing that whenever I go into a turn...It used to be very easy in my Mazda.

 

[lo bux racer]

All too true IMHO. Of course the throttle is just an electrical device, it can be moved anywhere...

 

[Azrael]

Lo Bux is right again!

 

[torqued]

You really don't need to double clutch in modern cars the old school domestic's it was more nessecary, you had to to up shift

 

[spattle]

I have a question....WHy can I not push in the clutch, shift down and while clutch is depressed rev it to what it needs to be then depress clutch?

 

[iGod]

you mean, why cant you in theory to accomplish the same thing as heel-toe?

the idea of heal-toe is to exit a corner at the appropriate rpm in the appropriate gear. that requires braking. hence the heal-toe routine.

"If you are just downshifting in preparation to pass or the like, you may
not need to really Heel and Toe because you aren't on the brake. You can
Rev Match the downshift by tipping into the throttle a bit when declutching
so that the revs are matched."

 

[spattle]

Im asking why do you neeed to release the clutch in neutral to rev match. Shouldnt you just be able to keep the clutch in, rev, and then shift and release clutch. I dont understand why you would need to release and reengage clutch in neutral between shift.