ive heard it over and over but i dont know what it is, maybe also the fact that this is my first manual transmision car so i havent payed much attention. could someone please tell me what double chutching is and what the right way to perform the action is.

 

Search..
There are A LOT posts about this..
I myself posted one of these couple of months ago..

 

i searched and couldnt come up with anything, sorry.

could you at least tell me what it is?

 

Shouldn't this thread be moved to "Driving Technics"?

https://www.evolutionm.net/forums/sh...light=heel+toe

 

ok thank you.

sorry for clutering this thread up

and this thread is now closed. another reason i didnt put it in driving teqniques is because no ones is ever there. once agian im sorry

 

It's something you really don't need to know about with the Evo, but here goes an explanation, because you need the explanation to understand why double clutching is done on some vehicles.

There is a shaft in the transmission which normally spins at the same rate as your crankshaft in the engine. This shaft is called the layshaft. When you press the clutch pedal in while in 3rd gear (or any gear, but we'll assume 3rd gear for this example), the layshaft is now disconnected from the engine, but as long as the gear selector remains in 3rd gear, the layshaft is still being turned (through the transmission) by the wheels.

When you slide the gear selector out of 3rd gear into neutral while the clutch pedal remains depressed, the layshaft gets disconnected totally -- it's not being turned by the engine (because the clutch pedal is depressed) and it's not being turned by the wheels (because the transmission is in neutral). So the layshaft starts to slow down its rotation.

Assume that you now try to shift the transmission into 2nd gear, still with the clutch depressed. In order to engage 2nd gear, you'll need to increase the layshaft's speed above the speed it was spinning at in 3rd gear. But like we said, the layshaft was slowing down, not speeding up.

The Evo, and virtually every passenger car with a manual transmission, has a synchro (or synchros) which serve to speed the layshaft up to the correct speed as the gear selector is moved into 2nd gear. Thus, you can press the clutch pedal down, downshift, and release the clutch pedal, and in most cases, the gear will engage without grinding or otherwise complaining.

Now, some vehicles don't have synchros -- some racing cars, big trucks, probably other vehicles, most of which you'll probably never drive.

On those vehicles without synchros, double clutching is done to allow changing of gears (especially downshifting) without grinding or otherwise stressing the transmission.

To double clutch, the following is the procedure:

(1) Press the clutch pedal in, disconnecting the transmission from the engine.

(2) Move the gear selector to neutral, disconnecting the layshaft from the wheels.

(3) Release the clutch pedal, reconnecting the layshaft to the engine.

(4) Blip the throttle on the engine to match the anticipated engine speed in the new gear; this gets the layshaft spinning at the desired rate.

(5) Press the clutch pedal in.

(6) Move the gear selector to the desired gear. If you correctly matched speed in step (4), this will work without grinding.

(7) Release the clutch pedal.


Be glad that the synchros in your transmission work as well as they do, because double clutching is a pain.

Some older passenger cars (modern, but old cars, like from the '80s) may require double clutching because one or more synchros are totally worn out and nonfunctional. If the car is a beater and not worth much, it's not worth fixing the transmission, so you just double clutch and drive it until it dies.

 

nice thanks dude

my questions are now answerd.

 

In my previous post, I stated that many race cars don't have synchros. One example is NASCAR Winston Cup cars.

But actually NASCAR Winston Cup drivers don't double clutch. Except for starting from a dead stop, they don't depress the clutch pedal at all.

It is also possible to shift any normal MT car without using the clutch pedal, but unless you are very good at matching engine speeds, you will cause an undue amount of wear to your synchros. The procedure is the same as the procedure for double clutching, just take out the steps which have to do with the clutch pedal.

 

FYI-

All of Porsche's race cars have syncros b/c Dr. Porsche invented the syncromesh transmission.

You can find this info and other interesting info in the book: Porsche High-Performance Driving Handbook by Vic Elford.

 

Than why the hell did The Fast and The Furious quote granny shifting, not double clutching like you should? Is this becuase they like to protect the cars against damage which I highly doubtor is it just mroe bulls#@t like the movie has on it?

Cheers

 

Yup

 

Yeah I think it's a case of the script-writers just picking out driving technique terms out of a dictionary and pastin them into the lines.

 

Another time I double-clutch is down-shifting for a turn. Since you want to have RPMs going through a sweeper or turn, I usually need to drop down a gear. It's pretty easy since you don't need to technically "double-clutch", more of this sequence:

1. Clutch in
2. Blip throttle
3. Downshift
4. Clutch out

Pretty simple and it keeps things moving smoothly. No jerky downshifts, saves the synchros (because they do wear out).

 

How many times have you seen people downshift while drag racing in the first place?

I know that double clutching can be used for upshifts, too......But then again, not that likely. If you have a need for ever double clutching, then you probably have a dog box and not helical gears. Not many street racers will ever have this. It was just more movie BS.

Blow the welds on the intake manifold? (sorry, that was a stock intake manifold, not a sheet metal one).

Glad to see they used an Eclipse GS for the movie, too. I mean, they didn't want to use anything that might be fast like a GS-T or a GSX. (Notice the 420a engine when they pop the hood, that is not a 4G63 valve cover...I have owned 2 GSX's before, I know what they look like.)

Why the hell am I rambling on about the inacuracies of a movie AFTER the sequal of said movie has already came out and is almost out on DVD?

Nevermind,

Josh

 

Because, my friend, like most of us, you still can't believe how gay the movie actually was after you actually sat down and analyzed it.

...it had so much potential.