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Discussion Starter #1
I'm not sure where to post this but:

This is how I understand heel-toeing: quickly revving the car while braking to ease the transition from a higher gear to a lower gear, so the point is to avoid the traction disturbing shudder common to downshifting and to keep the car from dropping revs too much and bogging. Is there anything I'm missing in my definition?

What's trail braking?

Anything else that needs definition, I say we start a vocab sticky somewhere.
 

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Discussion Starter #3
flynhighaf23 said:
maybe the racers section...
yeah, I thought of that first but I also thought that more people would be interested in terminology than just the racers section users
 

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heel and toe downshifting: Say you are in 3rd gear and coming to a 2nd gear corner in a canyon. as you break for the turn you put half of your right foot on the brake and half on the gas ( my foot is wide enough that my foot is still vertical rather than my heel on the break and my toe on the gas). You push the clutch down (with your left foot :) ) you then pull the shifter out of third. You let the clutch out completely with the transmission in neutral. You rev to the rpm at which you will be at when you are in 2nd gear. You then put the clutch back down and put the shifter into 2nd ( if you did it right there will be no resistance to the shift whatsoever). Let the clutch out and then if you did everything right you will be able to accelerate out of the corner cleanly. The whole point is to do the work of the syncros for them (by accelerating the transmission with the engine rather than the with syncros like a normal downshift.) so that you arn't pressing them really hard and wearing them out prematurely. It also sounds cool.

Trail breaking is breaking extremely late into a turn to the point that you must continue breaking through the corner as you enter it ( but only to the apex). So as you turn in to the the corner and increase the load on the tires you slowly release the breaking load on them (in proportion to the increasing side loading), there by keeping the tires at their maximum traction. It will reduce you lap times because you are essentially taking full advantage of the tires, rather than doing one thing at a time. you are multitasking (and your girlfriend says you can't multitask :smile: )


Hope this helps.
peace.
 

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Discussion Starter #5
so trail breaking is intended to keep weight on three tires instead letting it transfer to only two?
 

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that is more of an effect of it, trail breaking minimizes the time you spend slowing down and turning and maximizes the time you spend accelerating. it allows you to stay at a higher speed for longer compared to normal breaking. It will also allow you to make your braking time as short as possible, and it brings your breaking point closer to the apex of the turn.
 

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Grifter,
What you stated seemed to be both toe heeling and double clutching. Is double clutching necessary? All I do is Brake, then clutch in and rev match andat same time shift to the gear accordingly. BTW double clutching...is it usually slower then just straight revmatching shifting? To me it does.
 

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JWtcLA4AzN, heel and toeing IS double clutching, it is double clutching while you are also braking ( 3 pedals with 2 feet.) The whole point of double clutching is to keep the motor in the power band, AND to keep most (if not all) of the wear off your syncros. Since you keep the motor in the power band while you are braking you get the engine to help you brake, and you have power as soon as you need it.

If double clutching is slow then you are doing it wrong. It ain't as easy as it sounds to nail it, you can get close, but to hit it exactly is like shifing in silk, you dont even feel the syncros, there isnt any resistance to the shift at all. When you rev match you don't speed up the transmission before you down shift like you do in double clutching, its only the enigine you speed up, thats why you still wear the syncros. when you rev match all you do is stop the car and tranny from using its momentum to speed up the motor, its like half of the double clutch. When you double clutch there is no need to rev match cause the engine AND transmission are already going the same speed ( if you do it fast enough.) When I double clutch or heel and toe I do it as fast, or faster then the engine can rev( thats why i over or under rev shifts sometimes :) .) It becomes one fluid motion with practice. I always double clutch and heel and toe all of my downshifts. My brain won't let me just throw in into the lower gear. It is automatic. with double clutching you can do a 5 down to 2 shift as fast as a 2 up to 3 shift.

Sorry if i confused any of you.
Peace.
 

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Griftersdeuce said:
JWtcLA4AzN, heel and toeing IS double clutching, it is double clutching while you are also braking ( 3 pedals with 2 feet.) The whole point of double clutching is to keep the motor in the power band, AND to keep most (if not all) of the wear off your syncros. Since you keep the motor in the power band while you are braking you get the engine to help you brake, and you have power as soon as you need it.

If double clutching is slow then you are doing it wrong. It ain't as easy as it sounds to nail it, you can get close, but to hit it exactly is like shifing in silk, you dont even feel the syncros, there isnt any resistance to the shift at all. When you rev match you don't speed up the transmission before you down shift like you do in double clutching, its only the enigine you speed up, thats why you still wear the syncros. when you rev match all you do is stop the car and tranny from using its momentum to speed up the motor, its like half of the double clutch. When you double clutch there is no need to rev match cause the engine AND transmission are already going the same speed ( if you do it fast enough.) When I double clutch or heel and toe I do it as fast, or faster then the engine can rev( thats why i over or under rev shifts sometimes :) .) It becomes one fluid motion with practice. I always double clutch and heel and toe all of my downshifts. My brain won't let me just throw in into the lower gear. It is automatic. with double clutching you can do a 5 down to 2 shift as fast as a 2 up to 3 shift.

Sorry if i confused any of you.
Peace.
dbl clutching and heeltoe are different things. idealy they should happen at the same time although it doesnt have to.

heel toe is a technique that lets you downshift smoothly while braking - that's all. the key word is SMOOTHLY because if you're turning at the limit, a small disturbance of weight (jerk from downshifting) will mess up your balance and most likely you'll go drifting off somewhere.

double clutching is a technique that uses the clutch to simulate what the syncros do. so since the clutch is doing the syncro's work, you're extending the life of the syncro. that's used for gearboxes that doesnt have syncro mesh rings (ie full race tranny)

u can use them together at the same time or not, depends on how complicated you want everything to be. last time i checked the only time i ever seen double clutching is in inital d. never seen the pros do it in a production car
 

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JWtcLA4AzN said:
Grifter,
What you stated seemed to be both toe heeling and double clutching. Is double clutching necessary? All I do is Brake, then clutch in and rev match andat same time shift to the gear accordingly. BTW double clutching...is it usually slower then just straight revmatching shifting? To me it does.
technically it IS slower because you're pressing the clutch twice as much (as opposed to only once if you are driving normal). if you double clutch 2x faster than normal then you're shifting at a normal pace but your body is doing twice the work.
 

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It may be slower but it is all of about 1/10th of a second slower and it rev matches the shift and saves your syncros. So where is the down side?
 

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Ya....I guess that is why this thread confused me a little bit because you were the first one to mention double clutching when toe heeling....I usually just straight rev match it. How much of your syncros do you really wear off if you do a smooth rev match that matches almost precisely on the rpm after the shift? I would also think that in a road racing course that i would straight rev match then double clutch because 1/10 of a second per turn can sure add up.

I think for street use maybe double clutching more is better(even though I don't) and track use just straight rev match when toe heeling....
 

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Dont worry about trailer braking for the time being. Its pretty easy to misjudge the braking point and go skidding off into oblivion. Its also very very -very- easy to misjudge the amount of traction you have. So transitioning from turning to braking or the other way around rather can very easily lock a wheel or four up in very short order. If the MR2 is anything like my old VW then it'd be -very- easy to have the car get away from you under braking in the corner.

Brake early, turn early, accelerate early. Much easier and nearly as effective.
 

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You don't double clutch while heel and toeing, heel and toeing IS double clutching with your foot on the break.
To the question of how much do you wear the syncros with a smooth rev match the simple fact is you could completely miss the rev match and the syncro wear would be the same, too much.
The amount of syncro wear is minor per shift, but compared to double clutching where there is next to 0, there is enough wear that in several years there will be pronounced and noticeable wear. Also your statement of only rev matching on the track is incorrect due to the fact that although you do press the clutch twice, which you can do as fast as physically possible, it is still faster than just mashing it into the lower gear. It is like cutting aluminum with a jig saw or using a chainsaw, both work but the chainsaw is just a waste of metal. So heel and toeing will give you a faster lap than anything else, and have a tranny that still shifts after a few years of racing. In the years before pneumatic transmissions that shift for you (paddle shifters), almost all professional race car drivers heel and toed.
Also i meant the shift is a 10th of a second slower, not the lap time :)

KaceCoyote is right though, don't trail break without adult supervision, and make sure you have a place to slide really far when you miss the turn.
Peace
 

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heel and toeing IS NOT double clutching. you can double clutch while heel-toeing, but they are not one in the same.

heel-toeing is used to allow you to brake and downshift at the same time.
double clutching is used to saved wear on your synchros. in endurance racing, it may be useful to save some strain on your gearbox, hence where double clutching becomes useful in racing. in sprint racing it is hardly ever used.

i don't really feel like describing both, but they're not the same. i can suggest some good reading material if anyone is still confused: Speed Secrets by Ross Bentley.

-Mike

EDIT: grifter, it seems to me that you believe that normal rev matching is always double clutching. no offense meant by this, but that's what i'm picking up from your posts.
 

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Same here. Everything Ive ever heard was that heel-toeing is just a way to break and downshift at the same time. Double clutching has been explained already, but I do know that they arent both part of the same process of "heel-toeing".
 

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No big guy that is exactly the opposite of what im saying. I saying you should double clutch insted of rev matching. Rev matching is like double clutching except you still wear your syncros alot. So if your gonna rev match then why dont you just double clutch and save your transmission from an expensive rebuild. To me it just seems like people are to lazy to more their left foot one extra time.

In no way shape or form do i I feel that rev matching is even remotely close to double clutching. They are completely different. Maybe I didnt explain my self correctly or maybe you misunderstood me, but for the record I am fully aware that they are not one in the same. What im saying is that I feel that double clutching should be used INSEAD of rev matching.
 

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oh boy. Let me break it down


Double clutching goes as follows.
1.Clutch in.
2.Move from gear to N
3. Clutch out
4.Clutch in.
5.Move from N to next gear.
6.Clutch out.
Summary:Takes longer, is very very smoooooth and babies the tires and the driveline parts. Its a favorite of endurance events where you need to be gentle.

Revv Matching.
1.Accelerate to X rpm
2.Pull the shifter from gear to press gently on the next gear in question.
3.Apply gentle pressure until the shifter slips into gear.
Summary:Its pretty damn tough on the transmission and a number of hard to replace parts. Trick is that point A. these parts are pretty _______ tough. B.this -is- faster no matter how you put it.


As for trailer braking really the most effective way I've found to learn/teach it is to find a very experienced driver. Take a turn(ON A SAFE COURSE) a few times with him showing the way and then try it yourself.
 

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Griftersdeuce said:
JWtcLA4AzN, heel and toeing IS double clutching
looks like you are saying pretty plainly here. this is heel toe and this is double clutching

in the plain instance of heel-toe braking in a straight line, down from 3rd to 2nd...............

1. Apply brake with your right foot
2. Apply Clutch with your left foot.
3. By either putting your right foot sidewaze or tilting it to the right, engage the gas pedal while you are applying brake with the same foot, the right foot.
4. Revmatch, downshift, and release clutch foot while still braking.
5. Now, you are in 2nd gear and still braking

in the instance of double clutching from 2nd to 1st gear.............

1. press clutch in
2. take out of 2nd gear into neutral and let go of clutch.
3. press clutch in again.
4. put into 1st gear, revmatch, and release clutch

if you get good enough with heal toe, half clutching comes natural. when i autocross, i dont even use the clutch downshifting when threshold braking into a tight corner with a straight exit. What is nice about using no clutch when braking is you can left foot brake(which is another wonderful story)
 
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