[Jim Child]

[quote name='333pg333' date='Oct 4 2006, 02:18 AM']So Jim would you say as a generalisation that one t-brakes more in slower corners? [right][post="26612"]<{POST_SNAPBACK}>[/post][/right][/quote]



In general I find that to be true for me in my car. Perhaps I would find myself trailbraking more in higher speed corners if I was driving a higher horsepower car and carrying more speed into these corners.



It still seems like you're talking about switching over to LFB after you've completed a H&T downshift. I wouldn't advise that. If your right foot is already on the brake, finish up your braking/trailbraking with it. Changing over to the left foot isn't worth it in that situation in my opinion. It adds complexity, takes too much time, and you risk upsetting the balance of the car when you switch feet.



968's don't have turbo lag to deal with, but we do have to make sure we're above 4,500 rpms so that the Variocam is engaged. I use 3rd, 4th and 5th at all the tracks I go to, and 2nd as well if the track has slow corners. I shift 7 times per lap at the two tracks I race on most.

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[bibbetson]

One of the racing books that I read, the title of which escapes me right now, defined trail braking as the entire time from the point from turn-in AND you are out of the gas to the time that you pick the throttle back up. Although this differs slightly from the general understanding of the term, it really makes sense as your car is still biasing front tire traction as long as you are out of the gas, regardless of braking. The end result is still causing the car to turn in faster and rotate, which is the whole purpose of trail braking.



Although off topic, another nugget a professional racer once told me that has stuck with me for years is that your first turn of the steering wheel should be the greatest steering input that you make in negotiating a turn. Implementation of this ensures that you did not apex the corner too early.

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[333pg333]

I shift 11 and 15 times at the two tracks we run at mostly. I wasn't suggesting to swap feet during braking. Agreed too difficult for little returns. It was more noticing that you said that you left foot t-b on many of the corners and I just didn't get how you did this and downshift at the same time. (Which you obviously don't) I am fine with l-f-b and using throttle at the same time if needed so long as the corner doesn't require a lot of hurried downshifting before it. That's when it baffles me as how to do the t-b'ing? Maybe brake later and jump more gears when downshifting. Instead of 5th-4th-3rd-2nd, go straight from 5th into 2nd with greater revs while h&t'ing? I already go 5th - 3rd on a few corners.

Bibbetson, I'm not sure that you still couldn't apex too early by making your first turn the one that counts? It sounds like he was suggesting late braking and late turn in. I think some guys refer to it as 'Square turning'.

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[bibbetson]

As for the steering input comment. The idea is if you turn the wheel for the corner hit your apex and have to turn the wheel again to finish the corner and not drive off the track, then you apexed the corner too early. Of course there are always exceptions to the rule, but I've found that for novices, this really helps them to realize when they have done it right and wrong. I've also found in my instruction that self realization is the first step to self improvement. The same can be said for the throttle, if you have to crack the throttle to complete the exit of the corner you apexed too early and you know you have something to correct.

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[Jim Child]

[quote name='333pg333' date='Oct 4 2006, 09:38 PM']Maybe brake later and jump more gears when downshifting. Instead of 5th-4th-3rd-2nd, go straight from 5th into 2nd with greater revs while h&t'ing? I already go 5th - 3rd on a few corners.[/quote]



You'll get differing opinions on this, but I don't let the clutch out in each gear in a multi gear downshift. Sometimes I go directly to the lower gear, and other times I go through the gears to make sure I select the correct one, but either way the clutch goes in and out only one time. Letting the clutch out in each gear in a multi gear downshift just takes too much time in my opinion.

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[333pg333]

Jim I agree that H&T'ing down through every gear is time consuming especially when you go from one corner to the next with a short straight inbetween. You're constantly shifting up and down. I have never heard of anyone shifting down from

5th to 4th to 3rd to 2nd (eg) with only one clutch engagement though? Unless I didn't understand your explanation.

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[Jim Child]

You heard right. It works great. Just make sure you match the revs correctly.

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[mike]

As Jim said, there are more than a few opinions on whether to downshift through the gears sequentially or not. Personally, I like to downshift through the gears sequentially most of the time. Here is a link to a cool video of Leh Keen going from last place to first at a Watkins Glen club race and it doesn't take him much time to go up or down a gear. My 968 (or maybe it's me) cannot go through the gears like he is doing in this 996/GT3.





http://gscdownloads.com/race.wmv



mike

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[333pg333]

Bibbetson, yes I see what you're saying and I agree.



Jim, I'm still not sure that I understand you. If you are in 5th and you need to get to 2nd for a tight corner upcoming, are you saying that basically you pick your braking point and downshift by depressing the clutch once as you H&T so you get your revs up and matched to the gearbox, and go through the motions of moving the gearshift from 5th to 4th to 3rd to 2nd even though you've only H&T'd once? If that's the case I don't see the point? Sorry if I'm missing something obvious.



Mike, thanks for the link but atm my pc doesn't have sound so I can't get the duration of the shifts. I'll try someone else's pc.



Oh by the way, I've just been out for my first drive with the new KW suspension system fitted and the new PFC brake pads. All I can say is WOW!!! on both counts. This will in fact change drastically the way I approach the track this Sunday and I expect to cut 5 seconds off my last 1.55 lap...at least!!! I had Mo30 and 968cs shocks and springs but this is waaaayyy better. It just wants to go faster and faster through corners and propels you forward like a full race lsd does, I guess due to the increased traction?

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[Jim Child]

[quote name='333pg333' date='Oct 5 2006, 01:50 PM']Bibbetson, yes I see what you're saying and I agree.



Jim, I'm still not sure that I understand you. If you are in 5th and you need to get to 2nd for a tight corner upcoming, are you saying that basically you pick your braking point and downshift by depressing the clutch once as you H&T so you get your revs up and matched to the gearbox, and go through the motions of moving the gearshift from 5th to 4th to 3rd to 2nd even though you've only H&T'd once? If that's the case I don't see the point? Sorry if I'm missing something obvious.

[right][post="26667"]<{POST_SNAPBACK}>[/post][/right][/quote]



On a 5th to second downshift I'll generally go directly to 2nd since its always easy to find. On a 5th to 3rd downshift I'll generally go through 4th gear because 4th to 3rd is a straight shot with the shifter. If I go directly from 5th to 3rd I risk screwing up and grabbing 1st instead which would be very bad.

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[rustech]

I'm used to using decompression (engine braking) to help slow the car before the corner (not throught the corner since it can disrupt balance if not smooth). I tend to release the clutch slowly so it is a smooth decel, but is this hard on my clutch? Is this a commonly used practice, or something to be avoided on the track?



Secondly, what is "double-clutching?"

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[ether_joe]

When I downshift and engine brake under heavy braking, I tend to get into the ABS at that point, and the car starts to get a bit twitchy. This is normal yes for heavy braking?





I'm also interested about double-clutching as well. . .

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[Jim Child]

You'll always have some engine braking when slowing for a corner, but you shouldn't be relying on it instead of the brakes. The brakes were put on your car for a reason. Use them!!! A driver using his brakes properly on the track will absolutely destroy a driver trying to slow the car with engine braking.



You want to complete your downshift smoothly. The best way to accomplish this is to rev match the downshift by blipping the throttle with the clutch in to attain the revs that the lower gear will require. A properly rev matched downshift will always be kinder to your clutch than a non-rev matched downshift. With rev matching a good driver can downshift so smoothly that you can't even feel it.



There's nothing wrong with getting into the ABS under heavy braking. Twitchiness under heavy braking can be caused by an unsmooth downshift, slight steering inputs, irregularities in the track surface, or a bad setup. Remember under heavy braking the back end gets really light, so even small disturbances in the car's balance can become very noticeable.



Double clutching is completely unnecessary in a modern car with functioning syncros. If you want to play with it the sequence to perform a double clutch downshift is as follows:



Clutch in

Shift to neutral

Clutch out

Match revs

Clutch in

Shift to lower gear

Clutch out



Some people confuse it with simple rev matched downshifts or heel & toe which is rev matched downshifting combined with braking. Its neither of those things, and there's really no point in messing with it IMHO.

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[ether_joe]

very informative thank you. my issue is clear, I'm not rev-matching well if at all. hard on the brakes, engine idling, and engaging 2nd gear.



what's the target revs for say, 2nd gear?



also, is it me or are the pedals kind of tough for heel-toe? I can't seem to twist my ankle over that far.



And it's kind of a dangerous thing to be experimenting with. . .

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[Jim Child]

[quote name='ether_joe' date='Oct 5 2006, 09:14 PM']what's the target revs for say, 2nd gear?



[right][post="26698"]<{POST_SNAPBACK}>[/post][/right][/quote]



That's impossible to say because it depends on what speed you're traveling. You just need to practice, practice, practice. Sooner or later you'll develop a feel for it. Just make sure that while you're practicing have solid contact on the brake before proceeding with the throttle blip.



Most people accomplish a heel and toe downshift with the ball of the right foot solidly on the brake, and the outside edge of the foot blipping the throttle using the heel as a pivot point. If you're having trouble reaching, try bending your knee inward a little bit. This will put your foot in a more favorable position. I have yet to drive a car that I can't H&T in using the bent knee approach.



Others use the heel on the throttle instead of the outside edge of the foot. Try that if the first method doesn't work. I wouldn't recommend the heel on the brake and the toes on the throttle, although I've seen a few people who make it work that way. I think they must be naturally pigeon toed.

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[333pg333]

I thought pigeon toed would have helped the traditional way of H&T'ing? You would have to have very splayed feet to do heel on brake, toe on gas. Not the best way in my book.

Engine braking will occur naturally with a n/a car. I don't have nearly the compression to do this but as Jim says it's not designed for this purpose. Double de-clutching was more popular with cars that had no syncro although I still do this when my gearbox is cold and doesn't want to engage smoothly. Not on the track though.

As for downshifting, I go from 5th into 3rd often at the track although not often 5th into 2nd. This may change as my new pads are so much better. Makes me wonder how I stopped at all in the past!

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[rustech]

Thanks guys, this is great stuff to read to help me perfect my form.

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[Charles Geer]

[quote name='ether_joe' date='Oct 5 2006, 02:14 PM']very informative thank you. my issue is clear, I'm not rev-matching well if at all. hard on the brakes, engine idling, and engaging 2nd gear.



what's the target revs for say, 2nd gear?



also, is it me or are the pedals kind of tough for heel-toe? I can't seem to twist my ankle over that far.



And it's kind of a dangerous thing to be experimenting with. . .

[right][post="26698"]<{POST_SNAPBACK}>[/post][/right][/quote]





For me my target Revs are about 4800 RPM while heel toe braking.



I use the sound of the engine to shift gears and to downshift. Does not work as well on Heavily muffled exhaust.





Example:

When on a straight lets say you are in 5th gear at 6600 RPM traveling at a speed of 138 MPH.



When you slam on the brakes for the next turn you will notice your RPMs start to fall.



When it falls to 4800 RPM I H.T. downshift to 4th (This sends the RPMS back up to 6600 RPM)



As the car continues to slow the RPMs continue to fall and when it gets to 4800 RPM again I HT to 3rd.



Now that my car is in third at 6600 RPM and my foot begins trailing off the brake for the turn my RPM continue to fall but at at slower rate.



The friction created from turn at high rates of speed also slows you down a little which is allowing your RPMs to fall.



Just before the APEX sqeeze the throttle hard and your engine REVs should already be in the sweet spot (REVS should be about 4800 to 5200 RPM when squeezing on the throttle at the Apex to the turn)



As long as you on on a decent line you should be able to get through the corner pretty fast.

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[bibbetson]

The pedals of our cars are very well placed for HP driving. When I first started learning h&t, trying to practice on the street, I found the same problem - the pedal felt really hard to reach. It mostly had to do with the height of the pedals, not the spread. On the track it was much easier. Finally I figured out that you just can't stop hard enough on the street to properly align the pedals without scaring the heck out of someone around you. The difference in brake pedal travel from really hard braking and street braking is tremendous. When you really get hard on the brakes, the gas pedal is only a slight roll of the ankle away so you punch the throttle with the side of your foot.



First timers trying h&t get too caught up in the term "heal and toe" and the rev matching aspect of it. Brake hard, while still braking start your downshift, just before you release the clutch smack the throttle however you can, let out the clutch while the RPM's are still high. Don't over rev the motor, remember you are in neutral. You aren't holding the throttle, trying to get the perfect RPM's - just stab the throttle and somewhere during the rev up and the rev down of the motor you will release the clutch. It's all about timing. The better you get at it, the closer the engine RPM and drive line speed will be and the less disruptive the shift will be. Only doing an OK job at h&t gets you 90% of the results.

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[333pg333]

So Charles do you actually watch your tacho to match your rev's precisely? I'm more like Bibbetson, I do it by feel and engine noise although I agree it's harder to hear on the track w helmet on. Having said that I do most things like braking points and turn in points by feel if that makes sense. I know it's not as precise as one can be but it gives me more time to focus on other things.

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