TD in DC

I did not mean to imply anything. I merely asked an honest question.

I do know that when I am braking in my car, it feels like I can stop faster without locking the front tires up if I brake without depressing the clutch pedal any longer than absolutely necessary to shift using heel/toeing to rev match.

I "think" that clutch engagement may affect the effective brake bias of the car (I understand that it does not mechanically change brake bias like a bias adjustment valve would) such that it makes it less likely to lock up the front wheels if you do not have the clutch pedal depressed. It feels to me like it is easier to lock up the front wheels when you brake with the clutch in, not to mention the fact that I think it would take you longer to get back on the gas (with revs at the right level) in the event you have to take an evasive measure in the braking zone.

Techno Duck

Alan, my wording is a bit off. I meant that as i am approaching a turn i start braking. Ive only experimented with carrying my braking into a turn at auto-x and have gotten pretty good at it. It was weird the first time ive done it feeling the rear end swing around so easily.

I think this is called trail braking? I would be scared to ever try this on the street or even on a track as i find braking even a hair to much will send the rear end swinging.

Anyhow ive never been to a actual real race track, my 'racing' experience is mostly 2 seasons of auto-x. My actual driving experience is only about 5 years.. . Hoping to get into DE next season.

Alan Herod

TD -- I don't think that anyone is recommending putting in the clutch until you intend to shift gears -- I just think that it is a complex process and some of the typed descriptions may not actually be what was intended.

Techno Duck - Autocross is good for learning all these techniques in a good, safe environment - and generally at lower speeds then you will encounter on the race track. What you describe is trail braking, but, I heel-toe shifting is hard enough for a beginner without introducing heel-toe shifting while trail braking.

VaSteve

It's a bit easier in the 944. But since I'm not going to get a chance to track test it again until March I need to practice some more on the street. I don't seem to get as properly timed as I would like...I'm not putting it in a lower gear and dumping the clutch, but trying to get a general feel for how hard to "blip".


(numbers below are made up)
Say for instance you're entering a brake zone at 5000 rpm in 4th and want to take the turn in 3rd which would be at 5500 when you're done. Do you "blip" to only 5500 or, say, 5700, 5800, 6500?, and re-engage the clutch as the engine settles to where the gearing is?

(could I make that any more confusing?)

TD in DC

The biggest mistake that people make is not blipping to a high enough RPM. Assuming that you have a rev limiter, you can't hurt your car by making too big of a blip. The larger the blip, the more time you have to complete the shift. The smaller the blip, the faster you need to be to complete the shift.

The release of the clutch should be crisp. (check out walter Roehrl's videos). If you are not quick and crisp with engagement and disengagement of the clutch, or if you shift after the revs have fallen too low again, the heel/toe rev match was entirely wasted and unnecessary. You might as well have done what Chris and Alan described, which is merely slipping the clutch, no matter how long, to bring the revs up more smoothly than you would if you released the clutch crisply when the revs were too low.

VaSteve

Right of course in concept. Now putting it all together requires braking hard and pivoting the foot enough to give a good blip on the gas and releasing the clutch "crisply" which is not a natural street driving techinique. I still need a bit pf practice....which I'll do in the 944. I don't see how practice this, let alone do it, much in an old 911 with all clutch pedal travel. It's been a while since I have been right seat, do you old 911 drivers move the whole left leg to work the clutch....I honestly don't know what I do in mine, but figure it's more than just my foot.

TD in DC

I am not saying it is easy or intuitive. But failing to blip enough makes it much harder. Think of it this way: If you blip too much, the revs just fall into place when you release the clutch and your car stays completely settled. By contrast, if you don't blip enough, the car will lurch when you release the clutch UNLESS you let the clutch slip out (even if for a relatively small amount of time), which means that your efforts to heel/toe rev match were entirely wasted because you could have achieved exactly the same result by merely slipping the clutch out . . . In light of the difficulty of replacing the clutches in 944s, I do all I can not to slip the clutch at all.


I actually rev/match on every downshift all the time even in the city. I know that it is much easier in a 996 and a 944 than in an older 911, but if you don't drive the same way all the time, it is much harder to develop good habits. At least in a 996 and a 944, you can easily rev match even if you are not threshold braking.

VaSteve

Oh please...you just do it when you swap the motor.


Right, right. I get the concept and I know it isn't easy. Rev match with some clutch slip is a lot easier than snapping off the clutch especially on the street.

I don't drive a 5 speed on a daily basis so I need to think about what I do, or plan an "errand"

I'm curious as to how the old 911 guys do it on the steet and track...Alan, et al, ring in.

racer

VaSteve -

1) get a manual for commuting.. it can be more fun!

As an old 911 guy: I heel/toe on the street and on the track. In my 911, I found that I would often lift my heel from the floorboard. I would position the ball of my foot so that the left part of the ball was on the right edge of the brake pedal. Then press on the brakes. I would then rotate my knee/ankle etc enough to blip the throttle (mid to top of the throttle) with my heel. As an alternate, instead of placing the heel to high on the throttle, I would litterally "roll" my right foot so that I was still applying pressure on the brake and blipping the throttle with the right side of my right foot.

Now. Obviously the pedals need to be adjusted so that as you reach maximum braking, your foot is also on plane with the throttle pedal. Also consider where the clutch "pick up" or friction point is. Too far away from the firewall can be just as hard to modulate as too close to the firewall. Also consider that type of flywheel will also effect how hard one needs to blip and when to blip. A light weight flywheel will rev up and down a lot quicker than a dual mass unit. These are the variables that make practice a must, until it becomes intuitive.

When jumping back and forth between Porsche and DD I still feel like a clutz the first couple of times till my feet remember just how each car behaves to my inputs.

TD- it is possible to overrev a car with an ignition based rev limiter. Those types of limiters work best "underload" of acceleration, but a blip of the throttle can exceed there ability to prevent an over-rev

As for the original thread question.

If the student only knows of the term, i would discuss the process and application OUT of the car, after a session.

If the student knows the terms and is getting the the point where, approaching a corner they 1) brake, 2) let off and downshift and 3) brake again, then I feel it is time for them to learn and practice Heel/toe, on the street and/or on the track.

As a sidebar, I have found that all my students who have had motorcycle experience (typically off road, but not always) have a much better feel for this skill. Whether it was something practiced (but not necessarily an acknowledged skill) or simply because motorcycles require use of BOTH hands and feet for successful riding.

Alan Herod

As an old guy, I practice it in all cars. The first time I tried it in the Audi my foot rolled between the brake and the accelerator. Needed to move foot farther right on the brake. The Honda is more difficult. Trial and error and practice, practice, practice. Some cars rotate the foot, others require rolling the foot.

PowerPuffGrrl

Hi all...this is my first post, but I've followed many of your threads and have been learning a lot from your previous posts. (and I personally know a lot you guys-so be nice ) Re the heel n toe...As one of those more "advanced" students, I've reached a point in my driving whereby I been advised that I need to learn how to do this to go solo. Better for the car too-no? Like Mr. C-4 Guy, I've been concerned about whether it's best to learn on the street or on the track. Frankly, on the track scares the bejeezes out of me since a mess-up will carry considerable impact. There is a lot going on when you're trying to do this technique and there's little margin for error. I also have a very small foot and when they come out with the aftermarket aluminum pedals for the Cayman S, I will get them-but for now, it's hard to reach. In the meantime, I'm trying to get some feedback from some of you more experienced track-rats. So--if you're not teaching on the track--what would you counsel a student to do when trying to learn this on their own--on the street. If there were a mantra to repeat in your head while practicing...what would it be? (I like the suggestion that you practice in a parked car just to get the feel of the foot movement.)

BostonDMD

Plenty of aluminum racing pedals for the Cayman S.
Ultimate pedals and Carnewall to mention a couple. I personally have the Carnewall, they are great and worth every penny.

Good luck

Sean F

I practiced on the street, but "learned" it on the track. In fact, the best day I ever had on the track perfecting the technique was in the rain. The rain really uncovers miscues. I figured out that I was adding brake pedal pressure while blipping. I found that out pretty quick in the rain as I went surfing into Big Bend at LRP a couple of times before correcting my technique (with the encouragement of my instructor ).

Larry Herman

Sometimes it's better to see it for yourself. Click here for a couple of turns from my Daytona race. Turn up the volume!

Going into turn one is a huge decreasing radius turn requiring a lot of braking. I downshift from 5th to 3rd, and then to 2nd before getting back on the power. Notice that the downshifts are smooth, and the transition from brakes to full throttle is seamless. Finally, the powertrain is always engaged, except for the briefest periods during the downshift.

TD in DC

Are you 100% certain on that? I'm not talking about mashing down the throttle and holding it there for any length of time while in neutral or with the clutch medal in. I am talking about a blip -- on and off the throttle -- on a car with a normal flywheel (only because I have never driven a car with a light flywheel). For those types of blips, if you have a rev limiter, I don't think (I appreciate that I could be wrong on this) you can damage your engine by a very strong blip. I have been told this by a number of instructors, both amateur and pro.

In any event, I doubt you could even make it to redline because most people tend to underblip so they aren't even blipping that strongly when they think they are really pounding the pedal.