Heel and Toeing--Correct Technique
 

I've been practicing doing this lately to the point where its almost instinct and I don't have to think about it--god when you hit it right it just feeelzz GOOD! I have the Rennline race pedals and basically I'm just rolling my foot off the side of the brake and angling the other side of my foot to blip the throttle. I've been paying attention to my mph and what gear to downshift to at the appropriate time and was wondering at what speed or rpm is the optimum time to downshift--I was thinking it would be at the beginning of the powerband for that gear--ie from 3rd to 2nd gear if I downshift at 35-40mph it seems to keep the rpm's at around 3500. Is this correct? Do you blip the throttle to redline? or to a target rpm? More details from the pros please Thanks!

I smell a 50+ post reply;) Without going into details, (that will soon follow!), try the search engine first. You might find some answers there.

If you are going down through the gears then you want to do the shifting towards the end of the braking area, but yes, when you have done your braking and you are ready to get back into the gas then you want to be at the low end of the powerband.

Generally when you blip the throttle you want to blip it to just the right point to get the car into gear not to redline.

I've found that heel and toeing is not all that difficult to do with the stock pedals. When you're downshifting, try to pick the gear where your speed translates to high point in the RPM band. For example, if you slow to 30 mph, it's better to downshift to second rather than third, since you're higher up in the rev range in second. Before doing this, it's best to figure out the fastest you can go in certain gears. For example, I know that third goes up to about 95 mph on my SC, so I can downshift into third at speeds lower than that.

Also, when you're downshifting, it's best to rev the engine to match the revs you expect in the lower gear, not to rev to redline. The idea is to match the engine speed with the gear speed so that you can shift more quickly and easily.

Seems I'll have to learn to heel and toe on a new car, as my 911 just sold and a guy is coming in from Denver to pick it up on Sunday. Oh well, new adventures!

CONGRATS STEVE! BRING ON THE BOXTER! Let us know when you pick it up.

Back to topic, it also does seem to help getting the car into 1st if I blip the throttle slightly when trying to engage 1st and its sticky--but generally not going more than 15 mph will anything work on my car.

So you've already answered my questions, 1) downshift at the low end of the powerband so you can accelerate quickly and 2) only blip throttle to 'target' rpm which will match engine speed to tranny speed. Thanks!

The whole point behind heel n toe is for the engine to be at the correct rpm for the speed in the next lower gear during a downshift.

This does a couple of things.
1 It decreases stress and wear and tear on the engine, tranny, and running gear
2 Have you ever downshifted and just let the clutch out without blipping the throttle, theres a moment of strong torque braking from the engine while the weight of the car accelerates the engine up to the new speed in that gear. That might not be too bad if you are slowly rolling to a stop, but if you are under heavy braking and your rear tires are just about ready to lock then the extra braking effect from the engine can cause them to lock. As you can imagine locking the back tires when the rear is already light because you are braking can be bad and result in a quick spin at best. For the same reason you wouldn't want to over-rev the engine for the next gear because the extra thrust at the back end will again unsettle the car and result in less than ideal conditions.

Assuming you get the revs just right you shouldn't feel anything in the car, no lurching either forward or backward.

Yes, blipping the throttle should help a car go into a sticky first gear.

Jon, your list of vehicles reminds me of a house that I pass everyday on the way home from work. This guy has a Z06 Vette, a Ford Lightning pickup, and a Chevy SS pickup. I'm not sure why the two pickups since most people like one or the other.

Steve--Thanks for the explanation--yes the Porsche/Dodge combo does seem odd but I really like the truck and the 345hp Hemi is unbelievable in the truck--I'd bet it is as quick as my SC was before the transplant--scary.

Watch the tach when going up through the gears. For example, shift from 3rd to 4th at 7K. When you let the clutch out in 4th, say the rev's drop to 4,500 (only an example - YMMV!). Now, when going down through the gears - ie, from 4 to 3, as you brake and the rev's come down to 4,500, you dip the clutch, rev to 7,000 - slip into 3rd, and the rev's match your upshift point - 7,000. And, as Steve points out - no rear tire lockup, trans, drivetrain damage, and you stay on the road!

But, if 7K is your redline - you probably don't want to be there - if you have to use the accel, throttle steer, you'll have nothing left.

Usually the drop in revs going up a gear is what you want to match when going down a gear. So, if you shift at 6K and the revs drop to 4,000 (in this example we are stroking the engine and not shifting at a 7K redline) then you brake until you hit 4K, clutch, roll the accel up to 6K, go down the gear and you are now in the 4-7K powerband with 1K in hand (is that a pun?).

This method allows you to adjust shift points for changing conditions and whatever the rev range is for the torque band - which is where you really want to be.

Okay, let me jump into the fray. When I downshift I rev the engine to try to match where it will be in that gear at that speed. For example if I am going from 3rd to 2nd and I've slowed to 35mph I'll rev the engine to 4K. So, is it only when you are using the brake that you would need to blip the throttle?

There are three main techniques that can be mixed and matched, heel-n-toe (braking at the same time that you are rev-matching to downshift to be ready to accelerate again), rev-matching (heel and toe does not NEED to be done on the street, so I will occasionally rev-match without the heel-n-toe part), and double-clutching (can be done with either of the other two and probably needs to be done on cars with grumpy transmissions - especially into first gear).

You can rev match without combining that with braking. I'll sometimes slow down, let off of the brake and then downshift with a throttle blip, or I'll get into the throttle early when downshifting on the free way to pass which results in the same thing.

Well, it all depends....

On the track, at the end of the straight, I jump on the brakes, and I go to the gear I need to get out of the corner with. For example, Lime Rock has a 3rd gear corner after a 5th geat straight. I'm racing so i try to simplify things...do less stuff, but do it better, so I just heel the throttle and give it a good blip, while I'm braking, (trail braking actually), and declutching. Select thrid (should slip right in if the blip has been generous enough) and clutch out. I have a 4 puck clutch on the race car which is a litte severe, so smoothness is needed.

On the street, i double clutch my 911. You can really feel the difference through the shifter, and I feel it's better on the 915 box to get the input gear cluster spinning happily. Hopefully the syncros will last longer! On the track it takes more time, and I haven't developed thesuper fast feet yet!

Just another point - another technique is to "hold" the throttle at the revs you expect the next gear to start in - rather than "blip". Just roll your ankle over and raise the revs to 6 or 7K - whatever the next lower gear starts in and then release the throttle at the same time you slip out the clutch and let the revs die....

Ironically, none of this has anything to do with modern technique - this is stuff that was important when engine braking was needed. Engines and trans were stronger than brakes and were used to slow cars down. Nowadays, F1 and prototype guys just slam directly (paddle shift) into whatever gear the corner wants and go from there...from 6th to 2nd in one go... the brakes and aero aids slow the cars faster than they can heel and toe anyway and engine management systems automatically match engine and trans speed. Add traction control and all of a sudden driving technique is not about controling the vehicle mechanicals... it's just about maximizing contact patch adhesion.... point and push!

If you've ever watched TV in-car foot shots of top race drivers, you'll see the clutch press and release as VERY quick matching a quick throttle blip. You'll also hear them matching new revs, but never/rarely going to red line. I've found rolling the ball of my foot awkward and use my heel for the throttle blip just as I'm about to do the shift and braking just about done. Still learning but it is fun, especially at a 2 gear down shift corner.
Ted in SoFla
'86 Carrera Targa...Solo at last !

Hmm, I think heel-n-toe is not so much for engine braking as it is for having your car in the correct gear when you are finished braking to begin to accelerate out of whatever you were braking for. At least these days, maybe it was a combination of both in times past.

That's actually why I said not to downshift when the next gear is going to be at redline, but to wait until most of the braking is done. Something that I read in Watts or maybe Paul Frere's driving book. If you have 100yds to slow down at the end of the straight and you need to drop a couple of gears wait and do all of the shifting in the last 20, 30, ,or 40 yds depending upon how fast you can downshift. If something happens or you don't get it quite right then you will be going much slower when you upset the car. Also, that allows you to concentrate on nothing but threshold braking from the beginning until close to the end.

I agree with 89911. There are many, many threads on this subject; not necessarily on heel and toeing, but on double-clutching. Heel and toe techniques depend on proper double-clutching techniques.

Sherwood Lee
http://members.rennlist.org/911pcars

Sherwood...The gate shift kit is working Great! Gave it a thorough wringing out at last DE at Moroso. Thanks for a terrific product.
Ted in SoFla
86 Carrera Blk/Blk

Geez Ted. Couldn't you have started a new thread celebrating the virtues of this product instead of burying it in this one? :) (nothing against jonT's thread)

However, I'm glad it has worked out for you.

Sherwood
http://members.rennlist.org/911pcars
and btw, www.seinesystems.com

Yep, engine braking (or breaking) no longer needed... with regard to "holding" the throttle at a certain rpm - all I meant was that you don't want to let the clutch out on the "downside" of the blip - that leads to wheel lockups as well. You want to let it out at the "peak" of the blip and then, as you continue to brake, let the revs roll down, by rolling foot off accel, until you are ready to accelerate again... Does this make more sense? Ted's point is well taken, it is a very quick, snappy, action. On the other hand, some of the engine/trans management systems nowadays do the rev matching for the driver!