Ok, this has been beaten to death. You dont need to double clutch our cars! The reason for double clutching is if your car does not have syncros in its transmissions. therefor you have to match the engine speed to the trans speed. Syncros do that for us, and you dont have to do it unless your syncros arnt working.

so why did Steve Mcqueen in Bullitt double clutch his car so of you ask....

read this:

The movie audio of the Mustang at high speed is not the actual sound of the car. Apparently, the editors dubbed in the sound of a Ford GT-40 at speed. This explains the multiple upshifts and double-clutching; the GT-40 had a 5-speed non-synchro ("crashbox") transmission.
There are times in the film when we hear the actual sound of the fastback. For example, when McQueen drives the car to his apartment (before the chase) and backs the car into a parking space. Also, when he starts the car and first leaves the car wash with the mobsters in tow. And pretty much all the shots leading up to when the Charger screeches away at the intersection.
To achieve that sound, the car had a modified version of the stock 390 exhaust system, according to my research. In 1968, big block Mustangs -- and all Shelbys -- came with a transverse muffler mounted behind the rear axle. That muffler is a crossflow design, similar to the muffler on hi-po Camaros of the same era. Ahead of the muffler and the axle were a pair of resonators in the sections of pipe right under the floor. Those resonators were essentially small glasspack mufflers. You can see a diagram of this system in most Mustang mail order catalogs.
What Max Balchowski seems ot have done is simply remove the transverse muffler and run a pair of tailpipes out the back. It's essentially a straight system with two small glasspacks. I have recreated this on my replica, using 22" glasspacks from a local muffler shop, and the sound is pretty close, judging by audio recordings I've made. However, you need to keep in mind that a 289 and a 390 sound quite different. I've never really cared for the way a small block sounds with glasspacks, the exception being the early Shelby GT-350s, which used Tri-Y headers with a much throatier sound.

i got it from here http://people.freenet.de/pony/bullittnews.htm

 

you are right. this has been beaten to death. but you are wrong. Some people (like myself) double clutch a 5th to 2nd downshift (or something radical like that) when you come off of a strait into a hard corner. My 2nd gear syncro's are shot. sheesh, leave it alone already people.

 

also, i have a buddy w/ an older integra who also autocrosses. He double clutches 3rd up and down b/c of shot syncros.

Put it this way "double clutching on a syncro mesh transmission extends tranny life. nothing else."

 

never really driven a brand new car with some power so I wouldn't know if a newer car needed to be double de-clutched or not. I don't double upshifting but I do downshifting, doing this does make some sense to me on the down shift.

As for tranny life, I'm sure it helps, but im also sure it reduces clutch life, a good trade off I would say.

 

I do it all the time. it's way smother and prevents the rear tires from locking up while downshifting. especialy in the rain.

 

I double clutch all my cars. It makes a difference, but slightly. Maybe it's just my imagaination. I think it's second nature to me and unfortuately, it gets me in trouble -- especially when I approach a light (damn 'stangs around here don't know double clutching from heel toeing from granny shifting).

Anyhow, it seems like it takes a little longer to get in gear with the synchros. When I get it right on a double clutch it's just smooth. Might not make a difference but it gives me more pleasure driving a car like that. FYI, I own(ed) a heavily modded FD with a street port motor and the usual mods plus, a '91 FC /w a JSpec engine ( a little sick), a '81 FB that's just gobs of fun, '87 Honda Accord (first car), '93 MX-3 GS V-6, and a SAAB 900 (ick). Some of the cars benefitted from different shifting techniques and others didn't give a darn. None of my passengers really understand what the heck I'm doing anyways, so I'm really the only person benefitting from the driving pleasure!

 

since im an uber n00b.......what is double clutching?

 

double clutching is defined as not using the search button so information has to be repeated (hence the double) for it to be grasped (like a clutch grabbing).

Seriously though, it's when you clutch, disengage a gear, release the clutch, then clutch and engage the next gear and release the clutch again. As opposed to clutch, disengage, engage, release clutch. It helps the gears "mesh" with each other, but newer trannies have Synchros that will adjust the speed when the clutch is left out relatively slow. Hope it help, and Quit Yer Granny Shiftin!