A friend of mine used to race in the up-and-comers league when he grew up in England until he grew too tall.
He showed me how to double clutch (now that I think of it - declutch?) in my Volks.
It's more of a high-performance trick to keep your revs up and momentum up without scrubbing too much speed and allowing you to downshift to the next gear while going around a corner.
This is what i'm trying out:
(1) as you approach the corner you take it wide
(2) you depress the clutch
(3) you quickly press the gas to bring your revs up to the medium to high point of the next gear and lift off the gas
(4) you then shift to the next gear and then gas it again and hopefully you will catch the sweet spot of the next gear in terms of revs as you enter the apex of the corner
(5) you exit accelerating and ready to take it back to the next gear
this way you don't have rev lag, haven't touched the brakes since you are using speed and rev control to corner and you can keep a higher overall speed and tire traction.
Anyways, this is what he's been teaching me. Takes a bit to move from your head to your feet.
I tell ya, it felt awesome. Made me realize how much more performance is in your car and how limited I was as a driver. Makes me want to take a high-performance driving class.
I usually have to double-clutch whenever I use reverse at first once backing out of the driveway. I'm driving a manual Nissan Sentra '92. Great little car, but the double clutching does have me worried a bit. I'm going to have it in for a service check before winter here. I just hope it won't cost an arm and a leg to get anything I don't know about fixed.
No. But my first 2 cars had worn/no syncromesh on 1st or 2nd, so I developed a technique that I feel is just as good. When approaching a 'give way' or stop sign (whether turning or going straight ahead). I'll slow down & down change from 5th to 4th to 3rd gear, then I's slow right down till almost stopping & as I do that I'd knock it into nuetral between the 2nd & 1st, if I have to stop before pulling out I'll then throw it into fist after I stop, If I can get away with crawling through & pulling away I'll throw it into 2nd just at that right speed where the revs match.
By using that technique, I never once crunched those gearboxes even though they had worn/no syncro on 1st & 2nd, in all the years I drove those 2 cars.
All you're trying to do when you "double clutch" is match the engine revs to about where they'll be after you shift, if you're downshifting, or just keeping them up while upshifting.
Letting the clutch out with the trans in neutral then re-depressing it accomplishes absolutely nothing. (except disengaging the clutch a second time)
Let's say you're downshifting from 4th to 3rd: push in the clutch, then rev the engine up a bit, roughly to where the revs will be after you let the clutch out. That saves syncronizers and blocking rings. (basically the same things)
When upshifting, you just pat the gas in between shifts to keep the revs up to avoid wear on the same components. Note: this practice is pretty much useless on newer vehicles with EFI, since the pcm keeps the revs up briefly when load is taken off the engine. It is more effective on older, carbureted vehicles where the rpm's fall instantly when load is released.
Listen to an old dump truck or semi next time you're next to one at a light. The engine revs up, then the driver pushes the clutch in, that's when you're hear him rev the motor between gears to keep the engine speed up so it reduces wear on the trans.
Interesting... I do that occasionally, and when I drove me friends Bug it was a must 905 of the time from a stop. now what I dont understand is heel-and-toeing??? I hear that term all the time in the car mags.... but what exactly is that???
Well 'heel & towing' can referr to one using their left foot on the brake & the clutch at the same time, while their right foot is on the throttle.
Then 'left foot braking' becames fashionable in racing circles (it started with the Scandinavian & Finnish rally drivers), where the clutch wasn't even used, & the feet were virtually always used to work the brake 'n throttle. Afterall the gearboxes were re-built for every race anyway, as ratios were always re-set to match the different circuts.
Eventually, a more sympathetic alternative was found, with solenoid operated clutches, where a solenoid automatically open & clossed the clutch when the gears were shifted. Even so, they still kept a cutch pedal in the car, because manual control of the clutch could come in handy, say when doing a 'handbrakie'. Even better some racing car drivers would fit one of those 'hand brake' pedals (like what were in big 'Yank Tanks' of the 70's), next to the clutch so that there were 4 pedals, yet because of the automatic solenoid clutch, really only 2 pedals were needed. The trick was to file the ratchets off the 'hand brake' pedal (well such rally/race cars still had the normal handbrake between the 2 seats, anyway), so it would automatically release when pressure was released off the pedal. These were often setup with a lip on it, so that when the foot parking brake was pressed down the clutch pedal went down with it.