Brian Morris

I have a question about downshifting. Basically - should you use engine braking at all? Right now I push in the clutch as soon as I brake and hold it in until I'm ready to downshift (with blip). Do most people leave the clutch out until they're ready to downshift - I'm thinking they probably do. Not only does this use some engine braking, but the revs don't drop as far for the blip.

--Brian Morris
89 951

JackOlsen

No. You do not want to use your drivetrain to slow the vehicle down.

Brian Morris

Jack - Does this mean you push in your clutch as soon as you get on the brake?

--Brian

JC in NY

The simplified answer is that there is never a time when you should be using "engine braking" on a racetrack because when you are not braking you are accelerating. There is no opportunity to coast at all.

rcldesign

In this case, I don't think he's talking about engine braking. Rather, it seems like he is wondering if he should just hold the clutch pedal in (while under braking) until he is ready to accelerate (in which case, the throttle is blipped, and the clutch dumped).

My unexperienced opinion is that one should dump the clutch and complete the downshift as soon as is possible (i.e. when the engine RPMs have dropped enough to downshift without overrevving). By completing the shift in this manner allows one to appropriately gauage engine RPMs during the initial downshift (rather than the car being at "idle"), and during any subsequent downshifts that may be necessary.

Karl S

Brian,

You don't want to disengage the clutch until you are ready to blip and downshift. Pushing in the clutch will allow the engine revs to drop to idle and it will be much harder to match revs on the downshift. If you have a long braking zone, you are probably going to have to drop down a couple of gears, so you may be using the clutch early in the brake zone as you downshift.

Karl

MJR911

I clutch in/ clutch out during braking, before turning in. HeelnToe

MJR911

I clutch in/ clutch out during braking, before turning in. HeelnToe

Brian Morris

After I wrote the question I wondered if "engine braking" would throw people off. Karl got the question and answer right. What I was really wondering was when to push the clutch in. As Karl said and what I think is right (but isn't what I do) is to brake, decelerate, then push in the clutch only long enough to downshift.

Right now my clutch foot and my braking foot are a little too connected.

--Brian

SundayDriver

Do everything smoothly and as needed. Brake, then downshift when you need to and use the clutch when you do the downshift. I would not let the engine idel down by depressing the clutch early. You will get some engine braking, but it is not significant and not really what people mean when they talk about engine braking.

OR - you can just skip the clutch part altogether. One less pedal to worry about but probably not the best idea for a synchro transmission.

late apex

My transmission (hewland)does not require the use of a clutch except to get started in first, and from then on just matching revs and avoiding "power shifting" are all the skills required. Coming off a long 5th gear straight to a tight 2nd gear bend, I I go from fifth to 2nd and it's back on the loud pedal. I do not believe in engine braking as properly cooled pads are cheaper than all those moving gizmos in the driveline that hate violent inertial changes.

mitch236

I go with the clutch/brake in and then the blip/clutch out when going to gas. That way, there is less unsettling of the car.

Joel

Brian,

Brake first and then when you are ready to downshift press in the clutch and complete the shift. If you only have a couple of track days I suggest you don't worry about heel and toe shifting just yet. If you complete a smooth downshift I wouldn't worry about hurting the car (obviously you wouldn't want to go from 4th to 2nd at Tremblant, but I digress!)

I'm sure everyone has different levels of driving skill and coordination. I found in my first few (quite a few actually) DEs that there was too much to do to worry about heel and toe. I ended up modifying my gas pedal to add a tab at the bottom. The new gas pedal plus the experience of several track days led me to heel and toe almost instinctively. I still have to work at a bit to get to that "2nd nature" level.

As always, Your Mileage May Vary!

mark kibort

As was said, dont even worry about heel toe. Also, do all your braking first, and then any shift should be a quick action. engine braking is not needed as we are talking about 10-20hp of braking forces, compared to 1-2000hp of brake braking forces!! So, as you get more and more skilled , your blip of the throttle can be done with continued application of the brake. if not, do all your braking in whatever gear the straight required, slow to a speed before turn in, blip shift and power through the turn. Never brake with the clutch in, as the rear wheels can lock u with no engine (even as slight as idle power is), and kill the engine and toss yourself into a tail slide, then you are really in bad shape!!

I cant tell you how many race guys I run up on, going into turns while they are messing with touching every gear on a down shift or heel toeing, and not braking anywhere near the car's capability.

first work on threashold braking,then trail braking during turnin, then later you can practice the heel toe method.

mk

StanSoph

In this video http://gscdownloads.com/leh/sebring/...bringHIDEF.wmv the driver downshifts through multiple gears instead of skip shifting. Is there an advantage to this? I think the heel toe execution is nice but it seems to be a lot of extra downshifts involved. I am a novice and wonder about his technique. If the link no worky, the driver goes from a long straight 5 or 6 gear to second or third on the decel prior to a turn and goes from 6 to 5 to 4 to 3 to 2. Why not brake and go from 6 to 2 ?