Here's a video with a good foot shot showing some classic heel-toe stuff... and in an rx8 no less...

rx8 doing a lap

 

I'm going to have to call you on that one - would you please care to explain exactly HOW double-clutching can possibly hurt the car at all, never mind too much?

Regards,
Gordon

 

I don't see how double clutching can hurt you car.

As for my self, I frequently do "heel and toe" but most streetcar pedals are not set up for this maneuver and they feel awkward and uncomfortable.

In racecars you adjust the brake and gas pedals so you can easily blip the gas when the brake pedal is pressed. It actually comes pretty natural when your pedals are properly set.

 

I'm still not understanding what "clutching twice" means - I'm picturing the following scenario in my head:


Approaching apex - step on clutch
shift to neutral
release clutch
brake
turn
rev match by blipping throttle
step on clutch
engage lower gear
release clutch
accelerate


Am I mistaken?

 

Damage car double clutch ... as in if you rev it too high and disengage the clutch and this will wear out the clutch... for me to rev the engine up too high and burn the clutch...

May be you are more skillful than me...

 

The reason for heel & toe downshifting is to maintain control of the car as you decelerate on the APPROACH to a curve. You start braking before the turn-in point, if you are approaching or past the apex, you're going to spin out, if you're carrying any speed into the corner.

As you approach the curve, light braking transfers weight to the front wheels to give more grip to the steering wheels. The downshifting (possibly multiple downshifts) need to be accomplished before you start turning, without changing the weight distribution of the car. I agree with the early comment that its difficult on the 8 because the brakes are so good!

From the Bondurant Training Manual..

First you start to squeeze on the brake pressure to slow down the car. Then pivot the heel or side of your right foot onto the throttle, maintaining even brake pressure [whoom bah]. Depress the clutch with your left foot, moving the shift lever quickly into the next lower gear. Release the clutch smoothly, then pivot your right heal off the throttle back to below the brake pedal and continue trailing brake.

My instructor used the sound " whoom bah" to describe the blip on the throttle. As mentioned by someone else, the idea is to increase the RPM's by about 1000 to match the speed of the engine to the lower gear. My instructor also suggested that the change of gears does not have to be LIGHTNING fast. Smoothness of the whole process is most important.

Please be careful practicing H&T on the street, or we'll have more threads on smacking up 8's. The only place I've felt safe practicing is on a sweeping off ramp, with no one behind me.

If you're H&T is for looks... never mind!

 

Once you start double clutching it becomes second nature, and you dont over-rev. You could also over-rev while rev matching with the clutch engaged to..

The only wear that I (and I am no expert) can see is that you are pressing the clutch 2x as much. This may wear out the throut bearing and springs quicker. However, are those (and the clutch) are easier and cheaper to repair than gears and syncros?

 

You are correct about replacement issues. It is much easier to replace a clutch than an internal transmission component. However, in theory, every time you disengage and then reengage a spinning clutch, you create wear. How much depends on the load and slippage incurred. I generally choose not to double clutch for this reason. All those downshifts add up over time, but that's just me. Also, a synchro is more likely to be replaced under warranty than a clutch because the clutch is a wear item, like brake pads.

 

I use the edges of my foot like many others here. I don't double clutch though.

I learned to H&T on my old pickup and use this method anytime I drive one of my cars... It probably sounds pretty funny when I'm cruising in my '91 Toyota pickup, slowing for a turn, and H&Ting... Only because the engine on that thing sounds like a lawn mower with a big box fan attached to it.

Anyhow, when I first got my '8 I was just getting used to pedal placement when I almost smacked into the backend of another car. You see, it was a freeway offramp (5 north @ Bake if you know OC) and at the end I was going to turn right. As I was slowing down, I was coming up on a car, hit second, and went to blip the throttle... My foot slipped off the brake, I was already commited to 2nd gear, and I blipped... The car surged forward, but I was able to get my foot on the clutch fast enough, then the brakes.

I felt like an ***, but eventually I got used to it. So, as Charles said earlier, be careful.

 

LOL... notice my nick

Being able to heel-and-toe the 8 was actually a condition for purchase (may be signing tomorrow!).

Every car is different, and so technique can vary by person and car. My Eclipse is awful for me... I have to do what you say: use the right edge of my foot to blip the throttle. Very awkward and not much fun.

My wife's civic is a breeze... keep toes on brake and pivot heel to throttle. But it's a bit of a reach.

The 8. Oh my, the 8... My first test drive, I did OK with it. The second drive, I was in heaven! We took it through an office complex, so I was just constantly accelerate, brake, blip, downshift, turn... repeat. And it was just all so EASY, so natural... I just couldn't stop giggling. You'd think I had owned the car for 20 years. Not that I'm normally good at it, but the 8 made me seem like a champ.

Any car that I can feel THAT at home with after two drives I just GOTTA have

 

Uh, yes! You don't coast around with the car in neutral.

The purpose of double-clutching is to synchronize the gear shafts for the downshift, rather than making the synchronizers do the work.

Say you're driving at 3000 rpm in 3rd gear, you want to downshift to second, and at that speed, 2nd gear would be 4000 rpm.

- push in clutch, move shifter from 3rd to neutral
- let out clutch (all the way), blip throttle to rev to ~4000 rpm
- push in clutch, move shifter from neutral to 2nd
- let out clutch, which smoothly engages!

The above process takes about 0.5 seconds. It's effect on smooth driving exactly is the same as rev-matching on downshifts, but the added benefit is that it reduces wear on the transmission.

You can double-clutch while you are heel and toe braking for a corner - instead of just blipping the throttle to smooth out the downshift, you add the extra clutch out/in as you move the shifter through neutral to reduce wear on the synchros. It adds extremely little time to a downshift, when done right.

Regards,
Gordon

 

BTW, there's something absolutely sweet about the engine sound when coming down from say 60 or so to a right hander (or left for that matter) when you get it right the throttle blips, engine compression, then acceleration...

 

I personally find the 8's pedal setup is difficult for doing heel and toe. The old BMW E36 is a lot more natural and perfectly setup for that.
Btw, does anyone using any add-on pedals (either brake or gas) on the 8 to make heel and toe easier? Seems there aren't too many pedals set are available for the 8 on the market!

Pete

 

To be honest... I just buy wider shoes. Sounds silly, but when I buy shoes I typically look for something that has a wider footprint. My Doc's are perfect for H&T... I just bought a pair of Sketcher shoes that work pretty well to. When I wear my dress shoes I have to skip H&T since the results are typically pretty jerky and somewhat unpredictable.

 

I ordered some sparco curva pedals. They have the little flange(sp) that sticks out at the bottom of the gas pedal. I tried the ball of your right foot and little toes method, but really dont like it. I want to be able to use most if not all of my top right foot to brake, and then be able to just roll my ankle to blip the gas. By getting the new pedal covers hopefully I can do this. We will see.

 

How to install those pedals? Is it drill on or clamp on? What I really want is something that can bridge some of the space in between the brake and gas pedals. I think they're just too far apart from each other, unless you have a really big foot!

 

I don't really see how double clutching wears out your clutch faster... You still do the same amount of rev matching, the only thing different is what is connected to what at the time..

Unless of course you rev to 9k every time you mash your foot down..

Of course, as I mentioned before there are other parts that wear more. I just don't think the clutch face is one of them.

Also, for you people who don't double clutch, how do you go from 6th to 3rd?

 

By going through 5th, then 4th

Sorry, I couldn't resist, lol...

 

For real? You go through 5th and 4th? I mean, what if you're cruising at 60 in 6th @ 3Krpm's then you all of a sudden need to be in the 6K + range... It takes time to go to 5th then 4th..

 

just curious on a side note, is it bad for the engine to rev up while the clutch is pressed all the way down? basically, i am asking if this scenario will hurt my transmission

cruising at 60 mph on freeway
have sudden urge to go into third :D
press than on clutch
while cutch is pressed down, rev to 7k or 8k and shift to third
then let go of clutch and zoom off:p

basically i am double clutching without letting go of the clutch. will this cause extra and unecessary wear on the clutch?
thanks

 

As long as you're matching the revs before you let out the clutch, then the clutch itself won't wear (much).

Some people say that unless you first pause in neutral, let out the clutch, then push it back in again and shift to 3rd... you might be wearing the synchros.

That may be true, but I've never done that, and never wore out any sychros. I figure I'm paying those synchros to do their job, so their darn well gonna earn their money, lol. Besides, I love the fluid movement of going from gear to gear.

 

There drill on. They have a bolt to hold them in place. Also, I have a size 14 feet. So no matter what, its hard for me to move around down there. They just get in the way most of the time. But right now If I try a traditional heal toe, all I get is floorboard, my foots too freaking long. That little flange on the gas pedal, will able me to brake with all of my foot (like an automatic) and just roll my ankle on the flange part. Thats what I want to happen anyway.

 

What you are doing is call rev matching. Double clutching is rev matching while engaging neutral.

 

ok, now i understand what double-clutching is and i know i don't do this...

what i do is not let go of the clutch at all while downshifting (given that at the current gear you're in, you're not at redline) and i keep constant pressure on the gas...with the clutch in and constant pressure on the gas, the engine revs up 1 or 2K and revs match...if i'm going down more than 1 gear, i'll apply more pressure to the gas to get revs up even more...

this works a lot better for me but i don't know the repercussions this may have...

 

same theory as far as I can see br

it's simply rev-matching