I drive an auto, so I am usually pretty clueless about this stuff. Can someone explain what heel toe shifting is to me? My understanding is that you are down shifting while at the same time pressing the brakes and the gas to try and match the speed with the engine revs (so that the engine is not slowing the car down with the downshift but the brakes are)?

I drive an auto too, I just learned about this a couple days ago. This site helps a lot, double declutching is of the same school and there is info for that too.

Double Clutching, rev matching ect is pointless on most newer production cars with a manual. This was an old school trick that was done before the invention of Sychros. (sp?)

The Syncros in your transmission now, always match the revs of the input shaft and the output shaft. You used to have to match the revs because if you didn't you were trying to match a input shaft at 2500 or so rpm to an output shaft of 1700 rpm or whatever. This equals grinding transmissions.

If you are having to do this on a J-body, this means your transmissions synchros are bad. Go get your transmission serviced. Now, don't get me wrong, synchros don't eliminate the need to have a clean quick shift and will not keep your transmission from grinding if you botch up a shift, however, they will keep you from doing major damage from one bad shift because the transmission is close to the same speed at all levels.

Some performance transmissions don't have synchros, it's a purist thing. Stock J-body transmissions are not performance transmissions. Period.

Wrong. Double clutching is for cars without synchros.

Rev matching is to save the clutch.



"The Blue Bullet"

Ohh something I really know alot about
You can't heal toe shift with an automatic.
I heal toe shift my car all the time and am damn good at it. I have to because my syncros are shot. Race car drivers do it so downshifting for a corner won't slow the car down (just the brakes), and it puts the revs where the need to be before the clutch is engaged wich shaves seconds off of lap times. I drive trucks (big rigs) so I know all about shifting my rpm. Big rigs don't have syncros, so you have the shift with the throttle and not the clutch, you basically rev the engine so its at the right rmp for the gear you need to be in and shift without ever touching the clutch (most drivers do it that way), although cars with sycros don't like to be shifted that way. Double clutching accomplishes the same thing as shifting my rpm (no syncros), you basically push the clutch in, let it back out in nuetral, and slide it into gear while pushing the clutch back in, while the rpm's are where they need to be. Just different methods.

Logan wrote:Wrong. Double clutching is for cars without synchros.

Rev matching is to save the clutch.

lol,

The clutch is the reason why you don't have the rev match the engine and wheels.

Proper shifting technique will save your clutch, not some FATF terminology.

Found this on an EVOLUTION website.

Danno is right, that is what it is, and no it isn't "required" in all cases. For racing/high performance driving, it is certainly recommended though. Here is why:

When you push the clutch in to downshift your engine slows down, but your wheels/gears/etc.. keep moving at whatever speed you are going. When you let the clutch out for the next selected gear the engine is at idle, and then in an instant you are trying to make it run high RPMs. The shock will lock up the wheels causing a nasty little corner-entry twitch, which may result in a spin. By "rev-matching" which is keeping the revs up while the clutch is in, you decrease the chance of that happening.

So.. it makes for smoother gearshifts that make the car more stable, and is easier on the equipment.

I am going to guess since this was moved from some other forum, that the person was asking about doing this during street driving.. You shouldn't be driving hard enough on the street to need it (obligatory public service announcement) but.. This is one of those racing things that can be practiced on the street, (along with heel-toe) without doing any more damage than drinking a little extra gas.



This is for a performance car. Not an economy car.

Basically, on your little 5 speed, Rev matching is worthless.

Sorry to be a gearhead but I cant help but to add this too. Syncro's don't make your input shaft and output shaft match speeds. The gears on the input shaft freewheel and arn't connected to the shaft. Your shift fork gear couplers are connected to the input shaft. The only thing a syncronizer does is make the coupler speed up or slow down to match the speed of the gear your selecting (wich is actually being spun by the output shaft gears wich are connected to the output shaft) so they can mesh when shifting. Without sycros, you would have to use engine rpm with the clutch engaged, to accomplish this. Your input and output shafts never actually spin at the same speed (but 3rd gear is close. The only reason you push in the clutch at all with a syncronized tranny is so the couplers (connected to the clutch through the input shaft) isn't connected to anything and can change speeds to match the output shaft (wheels). A15 is pretty much 100% correct about the heel toe thing as far as racing goes.

A.15 wrote:

Logan wrote:Wrong. Double clutching is for cars without synchros.

Rev matching is to save the clutch.

lol,

The clutch is the reason why you don't have the rev match the engine and wheels.

Proper shifting technique will save your clutch, not some FATF terminology.

Call it what you will, rev matching when down shifting is proper driving technique...



"The Blue Bullet"

^^ if you do it right, the clutch and syncros will last longer. But don't ask me how reving the engine with the clutch pressed to the floor can effect tranny speeds unless you want another 300 word essay (to complicated for non-mechanics)

...where did I say this? Matching the speed of the engine to the trans is the idea....

Why do I even have to say this? We used to play this game in middle school where you be difficult and nit pick what people say because it is fun....



"The Blue Bullet"

Hey logan, I was AGREEING with you, not nitpicking what your saying. All I ment was that if your gunna rev match your car, doing it wrong can be hard on the car, and most people don't have the skill to do that. Other than that, I was actually backing you up, saying your right, in a round about sorta way.