I don't see how it happens either, but I get the impression that some of the people here shift in a manner quite unlike the way I shift; Specifically, they are pushing/pulling on the shifter harder than I'd ever push/pull on a shifter, even in a Peterbuilt. I shift with a very light touch, using my fingertips or palm, and I doubt the force on the shifter ever reaches a full pound.

I certainly agree with those who say that double clutching is not necessary with modern transmissions, but the S2000 is notorious for its weak synchros, just like the MG's I drove when I was learning, and it responds well to the very same kind of treatment. I know for a fact that my synchros will outlast the rest of the car, becaue I hardly use the things. It's not just a matter of what one has to do, because one can shift without using the clutch at all if one likes, but I was taught to drive in a manner that minimizes wear and tear on the car, and as hard as I drive, and as often as I drive hard, minimizing wear and tear makes a meaningful difference. Beyond that, the engine can speed up the transmission quicker than the synchros; I know this for a fact becaue I've tried skipping the double clutch on 2-1 shifts, and it takes WAY longer for the locking ring to release if you don't double clutch and that makes for a slower downshift. However, this may not be the case with the AP2's, because they have a heavier flywheel, so the engine may actually accelerate slower than the synchros can accelerate the gearbox. I really don't know for sure, but a good double-clutch downshift tends to be slower in vehicles with heavy flywheels (for a good exapmle, try the aformentioned Peterbuilt ).

Double-clutching is like trail-breaking. Those who can't do it well enough to benefit feel that it is bad technique (and it is, for them), and those who find that it makes them faster feel that it is good technique (and of course it is, for them). Anyone who has ever had to drive a crash-box has had to learn to double clutch to downshift, and has seen first hand that a crash-box will shift even faster, because it doesn't have any synchros or lockout rings, and you can shift a synchro box almost as quickly (if not as quickly) if you get a good enough speed match when you double clutch. But, like trail-breaking, it's not for everyone.

Heal/toe is another matter. You can't downshift under hard breaking without upsetting the cars balance unless you stab the throttle to get a good rev match before releaseing the clutch, and you can't be quick if you can't keep the car balanced, so heal/toe is a mandatory part of being competative on the track or autocross course.

Heal/toe is a requred part of going fast.
Rev matching is a required part of going fast.
Double-declutching is an optional technique that offers a number of advantages to those who take the time to master the skill (just like trailing brake).

Gosh guys, I'm still wondering how you can pull on the shifter hard enough, with the car in neutral, to unbalance the car. The amount of imbalance couldn't exceed the force applied to the shifter, could it? How can you put that much energy into the gearbox without overriding the lockout ring and grinding the gears? Sounds impossible to me, but I know people aren't just making this stuff up, so somebody needs to explain what's going on. I'm obviously overlooking or misunderstanding something.

 

Only autoX weenies care about 2-1 shifts, though.

 

Hahaha, it's sure not something you have to do very often on the track.

Some of the top autocrossers actually avoid shifting during a run, by getting into second gear as soon as possible, and just staying in second for the entire run. The technique is so effective that it is mandatory at the Evolution schools, and it almost always improves the students times as opposed to working the gears during their run. I was skpetical until I met a few national champs who used the technique.

Working the gearbox during a run (the way I like to do) does present more ways to screw up a run, so maybe only half-fast autocrossers care about the 2-1 shift.

I actuall shift into first quite often when stopping (on the street). It's one of the things you can practice on the street without driving like a mad man.

 

Yes, so double clutching, even in a tranny without synchros is only used on downshift. As far as heal-toe, downshifting without heal-toe, in a turn, will upset the car. On the straight is a different matter, right? Though I should get more practice at heal-toe this weekend on some twisty roads.

 

all day long. it keeps your foot from forgetting.

do the whole, heel toe, double clutch at the same time, then double clutch on upshift sometimes, which is unneccessary fun.

 

downshifting without heel-toe on a straight is also pretty unpleasant, if you need to slow down. you'll get a big jerk from the engine being sped up by the transmission input. although, if you don't need to slow down, then just rev-match without braking. basically on a straight, the only time you may need heel-toe is when you're coming up on a red light and you want to make the effort to practice. otherwise, if you just want to drop a gear and go, just rev-match.

 

toe and heel --> so you don't have to rev match, brake, rev match, brake, rev match, brake in seperate sequence. it makes the entire operation, just that much smoother. and it helps you stop quicker, since your compression braking is joined with regular braking (depends on your tires, but usually works a lot better than just braking. always use compression braking).

 

digging the old thread up,

I just bought a beater 88 corolla for $450 lol, and I guess the way the pedals are on that car, I can finally heel-toe

 

heel and toe is a must.

 

Someone once told me trail breaking is when you break pretty hard thru a turn. I think mostly used in FWD to minimize understeer. It must be incorrect information....or am I missing something?