RedlineMan

OK...

I'm going to be lazy and respond without reading all of the thread. Some said you don't want to rely on engine braking. No, you don't, as it really will not do that much. Neither do you want to worry about it if you are getting engine braking. It is really a non-issue.

What you DO NOT want to do is EVER have the drivetrain dissengaged for any time longer than it takes to shift. There have been occasions in my "career" when I had to suddenly stomp on the gas to re-accelerate past someone who lost it under braking when I too was in the midst of heavy braking of my own. If I had been you with the clutch dissengaged, I'd have clobbered the poor guy for sure.

You do not H&T until the next gear is within range. If that means a one gear downchange, then you wait until you are in a good rev range for that gear. If you need to change down more than one gear, you either do it twice as proper revs for each gear are attained, or wait and drop two gears in one shift when revs for the lowest gear are attained.

Personally, I like to keep revs moderately high, as this aids quick acceleration in those odd and trying moments of sudden need for same.

kurt M

Something else that I don't think has been mentioned is that most if not all drive train components are turning regardless of the clutch being in or out. The clutch only disconnects the motor from the rest of the drive train. The drive train is turning at relative wheel speed regardless of the clutch being engaged or not. Even if you are in neutral (not recommended) most of the drive train is turning. If you do a 6 to 2 earlier than you need to, even with the clutch disengaged, you will be over revving the lower gear set. Don't shift until the car is near or at the speed that is appropriate for the gear being selected.
How you shift is dependent on the car and gearbox. Street type syncro box is very different than a straight cut crash box or a sequential.

Over simplified generalizations. There are always exceptions.

1. The least amount of monkey motion activity by the driver the better.

2. Be on the gas or on the brake.

3. Play with your stick in the braking zones and you might be passed by someone that is still driving.

RJay

Late to the thread...Never is such an absolute term even when prefaced by simplified . Forgetting about when we're under heavy braking, I'd argue that engine braking is absolutely essential to limit cornering; its an effective way (sometimes way too effective as in lift and spin) of forcing weight transfer. Isn't that what throttle steering is all about? I've never attempted it on track (although I've done it many times at AXs) but the Chief driving instructor at Bertil Roos in an advanced drivers seminar I attended described a technique of lifting and immediately returning to throttle to get rotate the car in tight corners. Nevertheless, don't try that at home kiddies, experts only!

Lemming

I have to admit, this is one of my weakest areas as I tend to shift way too early and then have to hold the clutch in until I've slowed.

Geo

Don't confuse forcing load transfer from lifting with engine braking.

Engine braking should never be needed unless you're out of brakes or a ham fisted monkey IMHO. You should ALWAYS be able to slow your car faster with your brakes than the engine could ever contribute to braking. But as John said, I would never leave the car out of gear or leave it in the "wrong" gear in case I needed to accelerate. IMHO never, ever not be in a gear that you could not get full acceleration should you need it with the exception perhaps just as you shift to a lower gear while braking (you'll be pretty near redline at that point).

I had a long discussion a few years back with a Showroom Stock racer who doesn't heel/toe or go down through the gears. He brakes without shifting down and only selects a new gear just before he begins accelerating again. He tried to tell me all the fast WC drivers were doing this. Right. If you can heel/toe properly you will not have any more braking by not shifting than you would by heel/toeing.

Larry Herman

I guess I'm a ham fisted monkey then. George, if you have your car setup with less rear brakes so that you can trailbrake it hard when needed, like my Carrera was, getting some engine braking at the end of a long straight can make a 20 or 30 foot difference in slowing distances. If I dialed in more rear brakes, then it would be really nervous when diving into tight corners under braking, which would give up a lot more time.

The GT3 exhibits none of that nonsense, and you really only need to match revs for a smooth downshift. No engine braking required here.

Geo

If engine braking can reduce the stopping distances, then why wouldn't adding that much rear brake to the exact same thing? I don't get it. The rear contact patches don't care if the braking is coming from the engine or the brakes proper.

Larry Herman

You are correct, it would. The difference is that there are situations where you would like more rear brake, like at the end of a long straight into an increasing radius turn, and times when you would like less rear brake, like when braking down a curving hill, into a hairpin turn that you must trailbrake hard to get the car to rotate. I personally like a little less rear brakes in order to keep the car more stable under situations where you have to brake in a bending line, or you need to trailbrake. It is those times that you can really gain ground on other drivers. And at the end of the straight, I'll use engine braking to make up the difference. It is really about the way your car handles, and the way you like to drive it.

JimB

A couple of weeks ago they had an in-car camera on Schumacher during his qualifying lap. I think they counted 7 times he changed the brake bias in one lap. Obviously not all corners require the same bias. Unfortunately, those of us racing stock and most doing DE don't have the ability to adjust bias other than to play with pads.

It's been my experience that there are times when it is beneficial to drag the back a little. Sequential shifting as demonstrated by Leh does just that. It's like a quick little tug on the back of the car each time you let the clutch out. Not a big deal and very short but pretty effective at slowing and stabilizing the car in some situations. I would never say that it's not hard on equipment or that it should be done all the time but I don't think you can say that it should never be done either. It has it's place.

Just my 2 cents. I'm sure you guys will be passing me as I'm fooling around with my stick.
Jim

Geo

Heh, I'm too big a monkey to mess with brake bias anything like that. I'd be cursing in Chimpanzee by the second lap.