Keiichi Tsuchiya, Drift King, is 5'2" and he does perfect heel-toe on the S2000.

 

double clutching (sometimes called double declutching) saves wear and tear on the synchros, which is beneficial if you track your car a lot (as i do)

cheers,
diane

 

It's not really that hard to understand. Think about approaching a tight autocross turn at the end of a straight that got you well into second gear. Even if you have to almost come to a complete stop to make the pending corner, your braking time is very short, so you have to get from second to first as quickly as possible. The transmission will not go into first gear until the input shaft speed is matched to the road speed, and if you just push on the shifter and wait for the synchros to slow the input shaft, you *might* have time to finish the shift before getting on the throttle, but even if you do, you're overworking the synchros unnecessarily. Plus, the engine can spin up the input shaft much quicker than the synchros, so if you let out the clutch and rev, then clutch back in, you can get the transmisison into first a little quicker (because they synchros won't resist the shift while they do the work of slowing the gears down). I don't think it does any harm to a modern transmission if you let the synchros do all the work, as long as you don't rush them, but if you double-clutch, you don't have to rush them, and they experience minimal wear, while you get quicker downshifts.

Keep in mind that you don't actuall go through the steps of, clutch out, blip, clutch in, but rather that you blip and slip ... You don't have to let the clutch all the way out, you bilp AS you let it out, and blip again for the rev match as the shifter is sliding into the lower gear and the clutch is coming back out. Both feet, and the shifter, are all moving at the same time, so things happen more or less in parallel.

Diane, it is easier on the synchros, but if it made you slower around the track, you know you wouldn't do it.
I double-clutch on the 2-1 shift because it's a lot quicker than waiting for the synchros, and a lot easier on the hardware than forcing the shift.

 

Am I having deja vu? I swear I've read this thread before. Was it re-time-stamped? And yeah, I usually heel & toe, if not, then rev-matched downshifts at the very least.

 

Well that clears it up certainly, I suppose I'll just have to see it in practice to appreciate the merits of it!

Thanks for the detailed explanation, Red!

Mike

 

i second that, thankyou, red
it would appear uve given me somthing new to research, and sumthing to practice as well
now my interested in how i can use this technique to become the best shifter i can!

"on my way to becoming GodHand" *evil smile*

 

[QUOTE=RED MX5,Oct 3 2007, 09:24 PM] Diane, it is easier on the synchros, but if it made you slower around the track, you know you wouldn't do it.

 

[QUOTE=f1_fanz,Oct 4 2007, 05:33 AM]There is a turn at Summit Point Shenandoah circuit where double declutching comes in very handy.

 

Hahaha, haven't we discussed almost everything about the car at least a few times in the past?

 

Sorry, I should have said 4-3-2, not 4-2 directly. For the turn I'm referring to (turn before the bridge straight), you approach straight towards one point, then turn late and gun it out. I brake first, dc to 3, dc to 2 about half-way through the turn (which is high and loud), and there's lots of tire squeal as the car rockets away from the turn. Rev limiter comes on in short order, but the speed difference is significant.

I've tried just braking and downshifting without dc and the car chirps and and lurches.

HOWEVER, supposedly the AP2 has a rev delay at high rpm's that helps with matching revs on the downshift. If it weren't for the hard braking I do on the track (thus lowering the rpm's quickly), dc wouldn't be needed at all.

Cheers,
Diane