Pizza4Everyone

I'm learning how to double clutch. There're some videos I've found in Youtube got me interested. The whole purpose is to prevent from over pressuring your engine at high RPM while downshifting. How to do it? Hmmm.....first you let go your clutch on neutral while driving appx @ 3000rpm. second, apply accelerator to rev match your rpm on neutral; (TL needs about 3500~4000rpm). Third, clutch in for downshifting and quickly let it out as you apply gas. I kept practicing for a couple of days and transition from downshifting got lot smoother with less lurking.

iforyou

iTrader: (1)

I thought it's not really necessary for cars with synochronized gearbox, this technique is mostly for large vehicles like trucks which have the older but more efficient unsynchronized transmission to help match the crankshaft's rotational speed with the gear's rotational speed. But since most cars now have synchromesh gearboxes, they do this automatically and double clutching is not necessary and wear is already reduced. But I guess double clutching would reduce the wear even more? And yea, it's a great skill to have too.

bigdo26

It is only necessary for transmissions that are not synchronized. Check the below link for a great description of synchronized transmission clutching and non-synchronized.

Not that double clutching would hurt anything though. Good thing to practice!

http://auto.howstuffworks.com/transmission.htm

01tl4tl

if anything- learn to heel toe drive and go to the nearest race track for a high performance driving school- then have some real fun

iforyou

iTrader: (1)

yea, heel and toe is a more important skill to have, I think double clutch is a higher level technique.

I hate cars

I think heel and toe/rev matching is what the original poster meant but I could be wrong. Double clutching is useless in the TL unless you're shooting for 1,000,000 miles on your trans.

iforyou

iTrader: (1)

I think he really meant double clutching since he mentioned about shifting it to neutral and give it a little gas then shift into the desired gear.

KaMLuNg

iTrader: (5)

i always thought this to be rev-matching on your downshift...

6spMike

You can rev match the engine to the wheels with a single clutch motion.
You need to double clutch if you want to match the transmission input shaft speed to the output shaft speed (the sychros do this task for you if you do not).

01tl4tl

These are not semi trucks people- double clutch rofl
Service Dept must love you needing a clutch so often, whats next- you use the trans to slow down all the time, downshifting, clutching thru each gear???
Brakes are to slow down the car!!

Heel Toe right foot gas/brake is where its at to make corner and be in the correct gear for exiting the corner on the power

If you have an auto trans- left foot brake right foot gas
try it!

6spMike

... Just answering the question. No argument that it's not necessary on modern cars. It's satisfying when you get it right, though, the shifter almost puts itself in gear. I only do it when I need a lower gear, not to slow down. There's no additional wear on the clutch if you do it correctly.

01tl4tl

As a mechanic who has done more clutch jobs than I care to remember
all I can say is every time you push on the clutch is presses and creates friction
which uses up material----think of brakes

To say extra un-needed use does not cause additional wear is incorrect

Synchros are there to make everyone good at downshifting and if you simply blip the throttle with the right side of your right foot while using the left side of same foot to push hard on the brakes while left foot is on the clutch action......
it will slide right into lower gear

The actual order is brakes hard clutchblipthrottleshiftclutchout GASSSSSS
Heel toe means right heel planted on floor as pivot for right foot to do a little dance with the pedals--exception to international members with rhd cars

I hate cars

Heel on the brake, toe on the gas. You're on the brakes while blipping the throttle to match revs for a downshift.

I see your point with the clutch wear. Theoretically if you match revs perfectly there would be no wear but I see what you're saying. Not to mention the extra motions of the slave and master cylinders.

On a side note and kind of gay, a friend of mine matches revs on his CL55 Mercedes. He has the timing down so good and the torque convertor on those care are pretty tight, that by shifting manually and letting off/hitting the gas at just the right time it sounds like a manual. The car is very loud for a Merc and we've had more than one person ask if it was a stick shift.

01tl4tl

In the really old days it was heel on the brake but with the advent of the 20th century, they put the pedals closer together and invented power brakes- which in the good old days were the power of your leg on the pedal- so in that case- yes heel one pedal toe the other, if you're driving say a 56 MG or Jag

My method is that as taught by Driving In Competition, an old school training book you had to read before race driver school...and is very comfortable

01tl4tl

there is always wear on the clutch!!
Rev match is the trans surviving longer

fiveoh-tl

.......and definitely not necessary on these cars.

iforyou

iTrader: (1)

yup! But seriously, it's cool if you do it correctly!