I watched the video of the Porsche running at Sebring that was recently posted here. I have heard of this heel-toe technique that people use when racing (or just driving to the limit). In the video, I saw the driver doing something like this while he was downshifting. What is the purpose, when is it used, and how exactly is it performed?

one foot clutch, one foot brake... one foot gas... hey wait!

The brake/gas foot slows the car down when needed, and keeps the revs up n ready to exit.


M

You downshift while you brake, thus saving time.

While braking with the ball of your right foot, use your left to depress the clutch pedal (disengage the clutch). Bring the car out of gear, let the clutch pedal out (clutch in), and use the heel of your right foot, while still braking, to rev the throttle to the correct RPM for the next lowest gear to be engaged smoothly. Then push the lcutch back in, put the lever in the proper gear, and let the clutch out.
While braking the whole time: clutch, out of gear, clutch, blip throttle, clutch, in gear, clutch.
It's easiest to learn with the car off while sitting in the driveway at first. Get the coordination down. Then go on a striahgt road and practice blipping w/o brake. Then try braking on that straight road with some blipping thrown in. Once you master it, go for it! It really helps the life of your tranny/engine, sounds cool, improves speed.

Do a Google, it'll explain better.

Cole

I put my foot between the pedals, and rock it sideways.


M

The idea is to brake with the right foot, use the left foot for the clutch, and use the other right foot to blip the throttle during the downshift.

You typically use the ball of your foot for the brake and the outer half for the gas. If you're doing a double-clutching downshift, you need to apply the gas as you pass through neutral on your way to the lower gear, and the clutch has to be let out briefly while doing this. This helps to match the speed of the two gears so they mesh properly. This is supposed to be the function of the synchros, but many racing gearboxes don't have them, and even synchro'd gearboxes can use some help.

We splay-fotted louts find it impossible to do the "classic" heed/toe.
I use the Miles technique.....even get it right once in a while

QUOTE (redshift @ Feb 27 2005, 09:06 PM)

I put my foot between the pedals, and rock it sideways. M

Same here, but figured he might want to know why it's called a "heel toe"

Cole

I think he was asking WHY?

The purpose is to keep the rpms up in the region where the engine performs as opposed to down low where it sucks like an AMC Gremlin with a bad valve job......

Race cars tend to be "peaky"..meaning that they are balls out at rpms not seen with normal cars.....my "S" motor can't get out of it's own way way until it hits 4,000 rpms....then it pulls like my old girlfiriend until 8K.....woooooohooooooo

I rarely get it right, but I do get it wrong alot, and easier!

If you can downshift really fast, and use hard turns to slow down, you don't need the brakes.. haha

It's like energy racing.


M

How about this explaination of why:

If you're ever noticed, when downshifting "normally" the engine revs up when you let out the clutch. This causes the weight of the car to shift forward. The change in balance is undesirable when your tires and brakes are already working to their limits. By blipping the throttle you can match the flywheel/pressure plate speed to the clutch disk speed so when you let the clutch out everything is already going the same speed and just quickly and quietly slips together without upsetting the balance of the car.

Hopefully that's a little more clear.

Also, the procedure listed previously combines double clutching and heel toe shifting. Two separate practices. You can heel toe without double clutching. Clutch in, out of gear, into gear, blip throttle, clutch out.

QUOTE (McMark @ Feb 27 2005, 09:41 PM)

You can heel toe without double clutching.  Clutch in, out of gear, into gear, blip throttle, clutch out.

AAAAAAAAGGGHHHH!!!!

Cole

You guys are great! I now understand clearly. I now also have a new technique to try to make me a better driver. I know that my car in stock form can still easily outperform my driving but I get better every day. My synchros are not all necessisarily in top shape either (occasional grind when shifting up or down into second) so this will hopefully help. Thanks!!

hehe.. I had this long post earlier about how I hold the clutch 'just so' and I dumped it because I didn't want anyone yapping at how I was an asshole.



Ya know, if you use the clutch like that, helps the shifter feel it's way to the RIGHT next gear.


M

Asshole..you? Nah.....

Strange asshole....maybe

QUOTE (redshift @ Feb 27 2005, 07:06 PM)

I put my foot between the pedals, and rock it sideways. M

Hehe, that's the exact technique I use to keep the engine from dying when something isn't right with my FI