Double Clutch Shifting [Merged 11-8] clutching synchronizing

[Defiant]

Ah, pearls cast before swine.

Nice stuff.

 

[MyEclipse5]

It saves your syncros too.

For me anyway, when im downshifting, say from 3rd to second to corner i:

Push in the clutch
Put it in nuetral
Let out the clutch
Rev it a little to match RPMS
Press in clutch(while trying ot keep the revs)
Put it in gear
Relase clutch

My gear SLIDEs right in when i do this, otherwise, I ahe to kinda Force it into 2nd.

 

[Tallen]

Double clutching is totally un-necessary. NLTS baby!

 

[JayRolla]

This is all true and yes we dont have to double clutch, but ive researched it and yes it does save the tranny. If you just through double clutch into google you will see how many people say its good to double clutch a tranny even if it has synchros. Even my tranny mechanic told me to do this.

P.S. Im talking about a real double clutch not the Vin Diesel double clutch.

 

[SethA]

Double clutching is useful when shifting into a lower gear only.

push in clutch
move transmission into neutral
let clutch out (do not need to let out all the way)
blip throttle to rev match lower gear
push in clutch
move transmission into lower gear
let clutch out

With practice it can be done fairly quickly. Some old school race drivers still do this out of habit. As was mentioned, not necessary (but can be fun). I use it mostly to put my car in 1st gear when it is moving too slow for second (like when I am in the process of stopping for a red light when it changes green).

Seth

 

[JayRolla]

Well im at about 100,000 miles on my tranny, so it would last a little bit longer since the synchros are so old. Im hoping for another 15000 miles that would be nice.

 

[DSM1G90]

Just remember: to spin the tranny up to speed in neutral, this is the secret of it all ....

 

[2GEffect6]

The technique for that is called heel and toe.

Steve

heel and toe is used in drifting to hit the brake while still accelerating to spin the back wheels

 

[turboglenn]

didn't read this cause i'm ina hurry but i was alwauys told by old timers double clutching was letting the clutch out while the trans was in neautral between gears so it would spin things up to speed, then re-clutch and go into the next gear (basically lettting the clutch out once real fast in the middle of the gear change to help act a s a synchro)

 

[zedicus]

double clutching came about from people who don't know how to shift. the clutch is only there to act as a buffer for people who can't tell when synchronization occurs. Also even the synchros aren't needed. On off road vehicles we gut the synchros, saves about 4 pounds of rotating brass in the transaxle. Now back to driving.
<P>
The clutch is ONLY required to get the car moving from a dead stop. Be it a tiny civic or a double axle 49 ford 2-ton dump truck. You should be able to cruise around casually and NEVER touch the clutch. ALSO, you should not be mashing it into gear, destroying the synchros. It SHOULD slip through the gears with ZERO effort.
<P>
When racing if you can't out shift an automatic you are doing something wrong. Electronic paddle shifters and traction control and variable slip and all of these other 'features' are making people lazy. And you youngsters watching old movies with chase scenes hearing some guy trying to double step because it's easier FOR HIM to drive that way does NOT mean it's the right way to do something. When racing you should use the clutch, but only just barely, coming out of gear no clutch, partial clutch into gear and back out from clutch and back on full throttle before the guy in the other lanes automatic has time to snap second.