what are they? forgive my ignorance

S

I only double clutch when I need to put the car in first gear while moving slowly. The Imp is terribly stubborn about letting you into first gear even when you're only moving about 1mph or so. Basically you pump the clutch twice and switch into gear.

Heel and toe is a good way to take corners quickly. You brake into a corner and at the same time downshift into a lower gear. It is a hard task to master. I often mess it up..

Late!

these are techniques used when you have a trans without syncronizers like in a race car. you push in the clutch and rev the engine to match the rpm you should be at when you downshift. it is fun and sounds cool in our cars but isn't really necessary.

When you are going into a corner you have to slow down (duh). However, comming out of the end of the curve, you want to speed up (duh). So to speed up you want to be able to drop it into a gear that will demand a few thousand rpm's to get the best out of the "power band". Got that so far? So to slow down, instead of picking your foot entirely off the gas and stomping on the break - just take your toes and the ball of your foot and rotate your leg so they cover the break. With your heel, you keep the pressure on the gas, in doing so, you'll maintain the speed of the engine. When you take your toe off the break (because you are out of the turn), and drop the clutch, the engine will already be "up to speed". That's when you really stand on it and climb up the gear tree until the next curve, obstacle, etc.

Make um sense?

-Sambo

that was educational. i watched a video of a bunch of gt (?) jpns/german cars and the drivers were heel-toe'ing. now to practice on my own car... :-D

Heel toeing does help even in a car with synchros. It's main purpose on our synchronized cars is to not upset the balance of the car while in a turn. If you are already cornering at the limit of your tires and downshift abruptly that slight shock that results could be enough to break your traction. By heel toeing mid turn, you get a smooth engagement and can power on out of the turn.

Sambo your description is close but a little off.

It basically goes like this: Your going fast into a turn. Stay in your current gear and brake for the turn as necessary. As your car slows down, you'll need to downshift to stay in the powerband for the acceleration out. Engage the clutch and select the proper gear. You'll have to rev the engine to the same speed as the tranny in order to get a smooth engagement. So simply slide your right foot over a bit while still maintaining brake pressure and blip the throttle to match the tranny's rotating speed and release clutch. It should all happen fairly quickly and smoothly once you get the hang of it.

[This message has been edited by Eby (edited May 21, 2001).]

Man, I dunno if anyone has the same idea about what it means to 'heel-toe'.

When I 'heel-toe', what I do is keep the RPM's on my car up by feathering the gas with my toe, and in the main, I am slowing down (until the apex of the turn) with my heel.

I do this to keep my car from doing a nose-dive, understeering, or oversteering into and out of corners. If my description isn't 'heel-toeing' im doing something wrong, but it sure helps going through corners fast.

Look at this, http://www.turnfast.com/tech_driving/driving_heeltoe.lasso

David

**** Practice these techniques in an empty parking lot, and dont try these on the open road unless you have them down to perfection *******

i second ProgWRX's advice - scared the bejeezus out of myself and my poor passengers the first couple of times on off ramps...

I have a question about heel-toeing/ rev matching.

I understand not matching revs causes the synchros to do the "catching up" and it can unbalance your car. My question is, if you rev the engine faster then it should be to rev-match, can you cause any damage to the engine or tranny? I'm not talking 2000rpm over where it should be, just like 500 rpm or so.

-gpxl.
HopUps WRX Club
www.hopups.com (http://www.hopups.com)

if you give it too much gas when you blip the throttle, it will simply lurch forward(accelerate with a slight jump)

gpxl--
When heel-toeing or rev matching if you are too low with your rpms, the synchros have to work to get the extra rpms to "match", ie. "catch up" as you say.
Conversely, if you over-rev, the sychros have to work to slow things down to the "matching" speed. Here the synchros work in the opposite manner by "braking", so to speak.
I have found that rev matching works best for me if I rev the engine to about 300rpms more than the perfect engagement point, because in the time it takes the clutch to reengage the rpms will fall 300 and everything syncs up perfectly.

[This message has been edited by Xio (edited May 21, 2001).]

Xio-

Thanks for the info! I just started double-clutching and rev-matching so I'm still just trying to get the revs close to where they should be consistently. I just wanted to make sure my tranny wasn't going to blow up as I learn!

-gpxl
HopUps WRX Club
www.hopups.com (http://www.hopups.com)

Double clutch your downshifts, your synchros will thank you for the vacation. As for finding the perfect "blip points" it's just a matter of practice...after awhile you'll learn to do it without looking, just sound and feel.
Right now I am having to re-learn everything, cuz I just bought a WRX and the taller gearing changes all the "blip points" I learned for my RS. http://www.i-club.com/ubb-files/smilies/tongue.gif

there seems to be a mixing of the term heel-toe and double clutch in this thread. double clutching is used for matching the trans speed with the engine speed while decelerating. this is done by taking the car out of gear, letting the clutch out and blipping the throttle, then when in the sought gear letting the clutch back out. my camry had a failing second gear synchro and i became fairly inept at this. heel-toe is used to assist braking and acelerating smoothly through a corner. i'd say there are some very good descriptions here, especially that article that was pointed out. now try to do bpth of these at the same time. if you master that then you have mad skills yo.

http://www.howstuffworks.com/transmission1.htm

Go read THE BIBLE....
http://www.drivingtechniques.co.uk


It's absolutely invaluable.

You guys rock, we're going to turn the USA around yet.
For those of us with an automatic,
I recently did something I previously thought unthinkable, stepping on the brake while on the gas, this keeps the revs up and slows you down. I just hope the stock breaks are up to it. Hey, are my discs glowing?

I'd like to clear a couple things and build on what patryns said. There were a couple comments about the bringing the syncos up to speed so as to not upset the car. The syncros do not upset the car, the engagement of the clutch does.

You must match the speed of the engine to the speed of the wheels so that when you let out the clutch the car does not jerk. That can be done on a downshift without double clutching by just bliping the thottle during the shift. When you do it underbraking, THAT is heel toe. If you mess up, reving to high or to low, the clutch takes the abuse, not the syncros. (well maybee some, they still have to do their job which is to match internal transmission revs, but that's what they do!) The point is the jerk you feel, which could upset the car when at the limit, is differences in revs between the engine and the trans, not the syncros.

Double clutching is what you to either save wear and tear on the syncros or when you don't have them at all. It is done to match the speeds of the two shafts in the trans so you can slip the car into gear.

Overreving, underreving while you double clutch...Well I'm not even sure you would notice if you do it in a car with syncros! Even if miss the right rev the syncros will take care of the difference and it will go into gear. You might not even be able to feel the difference if you do it wrong.

As patryns said, if you can do a smooth double clutch a heel toe downshift, then you've got skill.