GTRPower

Hmm...

Trail braking...

In the simplest form, trail braking is the classic driver's stubborness to admit that he is braking into the beginning of the turn.

In other words- the standard driving technique is to brake in a straight line, then turn. Trail braking lengthens that "straight line" (in a sense) and how deep the driver trail brakes into a turn depends on how late the driver thinks the tires will stay glued to the ground with both braking and turning forces before it starts to brake away. The reason to use this technique is to maximise the length of the straight line speed and minimise brake time. If done correctly, you should be hitting terminal speeds for that corner/straight/corner all the time, with no available speed left on the track for that car, and if you do that for the entire track, you're probably going a good clip faster than everyone else, Mr. Computer Mind Racecar Driver...

This is also used to overcome handling or driving skill deficiencies...

Some front wheel drive racers use the brake to help the rear end come around but that isn't the fastest- since it requires them to be on the brake- which is more than not on the brake... Some brake even earlier, then drag the rear end around with understeering throttle or maintenance throttle (just enough to maintain speed, not increase or decrease it), then throttle lift to swing it around.

Rear wheel drive racers seem to be mostly "classic" drivers, and use throttle lift to get the rear ends around.

So does this drivel make sense? It's 1.30am where I'm at right now and I'm getting punchy. Or according to Greg, I've been that way ever since...

Dragonx

Good points all, people.

So if most of you are off the brakes at turn in, are you back on the throttle immediately? I'm sure you are rolling into it to keep the rears behind you so are you accelerating through the turn or are you holding moderate pedal until you are straight and then floor it?

I would guess that many of you haven't thought about it before. My track time is limited and not in the S2000 but I don't remember when I get into the throttle.

GTRPower

Dragonx-

You should be making smooth transitions from brake to throttle.

Threshold braking is getting to the point just before locking the brakes up ASAP. You slowly release the brakes and get on the throttle... starting with maintenance throttle, then easing it on. The rate of throttle/brake input is directly proportional to the traction circle limits. In theory, you should be trying to stay on those limits as much as possible- it means you are using all the available traction. In practice you'll find that everyone else seems to have higher limits than yourself...

dbrower

My time at Bondurant with the Mustang encouraged a lot of trail braking to get that understeering pig around a turn. Cars that need trailing brake really need it. On the other hand, the S2K is not an understeering pig, so use of trail braking is a questionable technique -- it probably means you went in to hot and are trying to save it at the risk of induced oveersteer. I can't think of a corner I drive where I'd want to trail brake this car, if I went in correctly.

I'm given to believe that MR2s were cars you really didn't want to trail brake, even more so than the s2k.

Now, there is a mode of trail braking that isn't braking som much in the turn as settling the front end; it's a more gradual release of the brakes before the apex than would be called for by strict straight line braking. There's still some value to this, I think, in some cars under some conditions. You certainly don't want brake release to be so jerky that the front end bounces up and reduces contact pressure.

-dB

Clark

There have been some really excellent points made here about trail braking so far. One use that hasn't been mentioned is for relatively slow corners where the turn is significantly greater than 90 degrees (somewhat hairpin like, though doesn't have to be that extreme).

In cases like this, since the corner is very slow, you aren't carrying a ton of speed THROUGH the corner, and by using trail-braking you can rotate the car (be careful) through the corner so that the car is better positioned (i.e. pointed in the right direction) to use more throttle on exit.

Clark

Allan Haggai

By the way Allan, how many understeering pigs do you know?

I had a 1996 Integra that I ran numerous track events with. It had a Type "R" rear sway bar, stiffer rear springs, Konis set at full firm in the rear, and 5 lbs more air in the rears than in the front....and it still understeered! The car was pretty good in med/high speed corners but required a LOT of trail brake in tighter corners.

With the S, I do maybe 90% of the braking in a straight line and gently trail the brakes at initial turn in to keep the fronts loaded, pick up even throttle immediately, and if I've set the corner up right the throttle is on the floor as the car passes the apex. Yee haa, a fast exit with just a hint of power oversteer and VTEC screaming.