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? proper way to double clutch?
Posted 21 June 2004 - 09:36 AM
And what does this accomplish anyway?
Posted 21 June 2004 - 09:51 AM
Can someone WHO KNOWS!!! please explane the proper way to double clutch.
And what does this accomplish anyway?
I am not sure how it is done (there was an article on this exact topic in Autoweek some years ago), but it accomplishes the following: When you are downshifting, touble clutch trick allows you to match the RPMs of the motor to that of your transmission , so the downshift is accomplished smoother, without the lurch.
There was a lady rally-racer on this forum, she might explain it in more detail.
Posted 21 June 2004 - 10:34 AM
If you do it fast, you'll end up revving the engine with the clutch engaged, which is fine.
This saves wear on your synchros and shifts much smoother. If your car or truck has a whole lot of torque, shifting without matching revs can be a pretty big shock to the transmission.
Posted 21 June 2004 - 11:21 AM
Posted 21 June 2004 - 12:11 PM
is there any advantage to doing this on my '00 OBS with 48K miles?
I just put in a short shifter too, which lets me switch a lot quicker, so the engine doesnt lose as many revs between.
Posted 21 June 2004 - 01:13 PM
The other half: Approaching a bend at racing speed, preferably on a track, you must also blip the throttle again before letting the clutch in, otherwise you will start a tail-slide because of the engine braking effect.
Posted 21 June 2004 - 03:14 PM
can you suggest the best method for finding out what speed to match? I suppose just keeping an eye on speed and revs.
That's it. I really only do it if I'm downshifting coming off a freeway (and there's nobody tailing me). I started off watching, but now I can hear when the revs are right.
Posted 21 June 2004 - 06:29 PM
Posted 21 June 2004 - 06:57 PM
I'm curious Phillip, How exactly was the clutch designed to be used?
Posted 22 June 2004 - 08:43 PM
Posted 22 June 2004 - 09:01 PM
Posted 23 June 2004 - 01:00 AM
Question is how does it help to let the clutch out in neutral then push it back in before downshifting? Why not just match the revs on the downshift but push the clutch in once, wouldn't that accomplish the same thing?
Posted 23 June 2004 - 04:55 AM
And why downshift coming off a freeway? I just use the brakes, then pop it outta gear without the clutch when my speed is low enough.
Posted 23 June 2004 - 09:41 AM
But hold on, before you all start popping clutches 50,000 times a minute, understand that this puts an extra strain on your clutch release system. I still stand by my notion that the throwout bearing clips broke off the clutch fork on my Legacy because I learned to double-clutch on that car.
And I can drive MT with the best in the world. Guys who have been driving MT for 30 years ask me how I drive so well, I just tell them I'm self-taught .
Posted 23 June 2004 - 04:23 PM
Posted 24 June 2004 - 01:23 AM
The first stage is intended to bring the gearbox internals up to speed, that's why the clutch pedal has to come up, otherwise you are just revving the engine.
Posted 24 June 2004 - 11:14 AM
Posted 24 June 2004 - 11:45 AM
Posted 24 June 2004 - 01:06 PM
Double clutching is completely unnecessary with a full synchromesh trans in good working order, the transmission itself has all the necessary parts to match the shaft speeds… they are called Synchronizers! (Sorry to be a smartass). The synhrcos have a cone area that leads the teeth and starts to wedge with the gear, this matches the shaft speeds before the synchro teeth engage. If reduced wear is your aim just shift a bit slower, this will give the synchros time to do there job more completely and still be faster than double clutching, and without the extra wear on the clutch (which is far more likely to wear out than a gearbox). If you doubt this conclusion then consider this... when you make a normal shift, without double clutching or RPM matching, when does the lurch occur? When you let out the clutch, right? Not when you shift. At this point the gears are already meshed, it’s the inertia of the engine and flywheel that you feel, and this can be lessened by simple RPM matching before the clutch is engaged.
Now, can double clutching help reduce grinding or hard shifting, Yes. But his is only compensation for worn or abused parts. In this case double clutching can postpone the eventual trans rebuild.
Double clutching and clutchless shifting can be fun to perfect and are neat tricks to impress the girls, but good stick technique and RPM matching are all you need to be smooth and quick without grenading the transmission.
Posted 25 June 2004 - 11:43 PM
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