I've been practicing double clutching on the highway and regular roads. I am not breaking hard or at all so I skip a step.

Example: On the highway I am in 5th gear going around 65, I will exit the highway via an exit ramp and wish to be in 4th before the ramp starts to curve.
Since I don't need to break much or at all, I pick a location to shift into neutral,
blip the gas while only on the gas pedal, and quickly shift into 4th while the revs are high. It feels very smooth.

I have been trying lately to find a long stretch of road and then shift to neutral
and brake hard, and pivot by heel counter-clockwise to blip the throttle. It feels like I can barely have enough force to blip the throttle enough.
My heel touches the base of the gas pedal, and it does not seem like enough.

Can someone give me some advice on this? I do it this way because a book by Skip Barber says it's the way to do it.

 

Sounds more like you are trying "heel and toe" down shifting rather than double clutching. Makes sense if you have a gearbox with syncros, and not an open wheel car with a non-syncro box (as used by Skippy in some classes). "Heel-toe" is more a figure of speech, as most actually roll the ankle so as to hit the gas pedal with the outside of the foot, rather than pivoting the heel around to do so. It all depends on your foot size, leg room, ankle flexibility and pedal set-up. If you are using a 911 with the floor mounted pedals, they can be adjusted to get the brake and gas pedal height right for you (but mind the brake light sitch activation). Everyone finds their own way to get this done.

 

The book "Going Faster" has photos showing the left side of the right foot on the right half of the break and the foot rotated and the right part of the foot
hitting the gas however you can do it.

They stress that the blip is to be done in Neutral because the you positively connect the engine and the input shaft.

So I am double clutch downshifting and doing heel and toe.

What I need to do is to position my foot on the far right part of the break, then manage to have enough right part of my right foot to slam the gas.

Still, I don't get how I could do this quick enough like the sound bites you hear
when the pros do it.

 

you can blip with the clutch in and drop ti the selected gear as the revs match. Coming out of gear, pausing, blipping and then rev-matching is OK if you have the time and feel like it. If you want to go fast on track you want to keep the car loaded up under power or braking not coasting. how you up and down shift is dependent on the gearbox and what you need to get done.

 

The pros rarely double-clutch downshift. It is really not needed in a synchro gearbox. In a non-synchro, many pros (and amateurs) will not even use the clutch or just do a slight dip of the clutch. If they are double clutching, it would be in a non-synchro box which will shift much faster than a synchro box.

What you have left out of your description is whether you are letting the clutch back out when you go to neutral. If not, then you are not double clutching and I think that is where the confusion is.

 

I release the clutch when in neutral then blip the gas. I stated that in error, actually that is the point the book makes about positively connecting the engine and the input shaft.

I think I need to be on the track where heavy breaking is required and then I will need to get a feel
for how exactly I decide to pivot or shift over to the gas while still on the break.

My pedals are stock and I have a 997 C2.

 

It is easier when you are braking hard. First, the brake pedal is lower, and second you need a hard stab of the gas in order to spin up the input shaft. It is definitely harder to have a gentle foot on the brakes and then do a mild press of the gas. Although it's good to pactice on the street, it usually does not mirror what you do on the track.

 

Double clutching is not essential if your gearbox has healthy synchros, but it can prolong the life of the synchros, especially if they are getting a little tired. I used to have a GTi with the classic VW weak 2nd gear synchro, and I felt that double clutching for the first ten minutes or so while the 'box warmed up was a good thing to do.

 

If you are new to this sort of thing, then I would not bother with double-clutching.

Heel-and-toeing on downshifts is a worthwhile skill, but you need to be braking much harder than is safe on most public roads. If you want to learn it, go somewhere where no one will be behind you when you start threshold braking.

You can see a little of what heel-and-toeing looks like in the video ("Let's go for a lap") in my signature, although you won't see the actual pedals.

 

Yep. Double clutching is a throwback. Not really necessary and Skippy is the only school I've heard of that teaches it still. The only modern boxes that are not synchro are boxes that you don't even need to use the clutch.

 

Howdy;

Points:

- Double Declutch is not necessary at all with a synchro box. If your gearbox is shot, get it rebuilt.

- The track is NOT the place to learn to drive AND heel & toe at the same time. One or the other, but not both simultaneously. Your brain will be too busy to learn both, and botching up downshifts going into the corners is not conducive to learning HOW to corner. It's not as easy, but you can learn the basics on the street.

- Read this. http://redlinerennsport.homestead.co...18HeelToe.html In fact... read them ALL!

 

And many of the non-synchro boxes today are sequential. Try double-clutching on one of those - LOL.

 

You can (and should) practice Heel and Toe everytime you downshift on the street.

I tell students to try it when you are coming in to a stoplight. Standard driving pracice is to leave car in gear and brake until just before it comes to a rest and then put the clutch in and shift to 1st while stopped.

Instead, run the car down through the gears as you come to a stop. Say you are in 4th going into the light. Drop it down into 3rd, complete the shift and then drop it down into 2nd. This gives you two H&T practices per stoplight... do it every time and in a month it will be second nature.

To H&T effectively on the track it must be as automatic as putting the clutch in to upshift. You should not have to think about it.

Some pointers to the advice above:

1) The ball of your right foot should be solidly on the righthand side of the brake pedal. The full strength of your leg muscles is delivered primarily through the ball of your foot (you can actually stand and balance on the ball of your right foot with your little toe in the air if you car to prove it) so using the ball of your foot puts the mine force on the brake where strength is needed.

2) The right side of your driving shoe should overlap the throttle pedal about 1/2 to 1 inch or so when you are using your normal braking motion. Don't try to contort your foot or any of the fancy stuff you need in "in-cars".... your braking motion should be comfortable, natual, and it should be the same whether you are H&T downshifting or not.

To get the Brake and throttle pedals in the proper position (as above) it is probably necessary to build-up the throttle pedal. I just use blocks of wood and tape them to the throttle with racers tape... frankly, this is both cheaper than the fancy metal pedals and also allows you to position the throttle EXACTLY where you want it..... you can use pieces of 1/2 inch plywood and add or subtract pieces to buld it up to the exact height.... generally, when you are at 50% braking effort or more, the right side of your shoe should be just touching or very slightly above the throttle.

3) At this point you can either rotate your ankle so that your small toe blips the throttle or you can also step down with your heel like you are tapping your feet to music (if this is your preference, you may have to reshape the trottle with wood blocks lower on the pedal).... but in eitehr case, you must practice so that you can blip such that the pressure on the brake does not change.... H&T should not affect your braking at all... it will take you many, many repititions to get this down.

4) You can H&T on light or heavy brake application.... its all a mater of varying the force and speed with which you blip the throttle.... it makes sense... under light braking, you are losing revs more slowly, and need less of a blip to match the revs... under heavy braking you are losing revs fast and need a pretty sharp stab at the throttle to get them back up..... you will find that thsi becomes second nature..... light brake light blip.... medium brake, medium blip... hard braking hard blip....

You should practice until you can downshift and absolutely not feel the shift... it should be totally seamliess... the only thing that should happen is the engine noise gets higher... just like you pressed a button on a video game.

5) Double clutching is not necessary unless, like me you have a pretty well used gearbox with worn and balky synchros... to me, double clutching is a much cheaper alternative to a gearbox re-build...

Give your self 6 months of daily street driving to get it down... practice, practice, practice and don't get frustrated... it will come

hope that helps

 

Yeah Mark, it's a little tough to do on my bike also, but rev matching on downshifts is critical for smooth drivetrain re-engagement, and that can be done on anything. Personally, I like to double-clutch simply because I can, and I like the rhythm. Also, though it is unnecessary on racecars with light weight (or non-existent) flywheels, on the older street cars with a 30 lb spinning cast iron flywheel, and another 20 some pounds of crankshaft, your syncros will thank you.

 

I agree. I learned the hard way with an old VW with 200,000+ miles, shot synchros in 3rd and 4th. Double clutch up and down to keep it from grinding.

Think of it like learning to dance. You have to learn the steps, and you have to match the music of the engine and brakes. The tempo is slower on the street but the steps are the same as what you'll do on the track.