Braking and turning in - Trail Braking

[flmkane]

Trail braking is a simple technique to get the rear end of the vehicle to rotate for the corner. For obvious reasons, it transfers more weight to the front of the car thus making the rear of the car light and easy to rotate before turning in for the corner. Hope that makes sense. Basically the technique is used with cars that tend to understeer and/or on real sharp corners.

I'm afraid you dont know what this technique actually is used for.

a) It's not simple. Balancing braking and steering perfectly is damned difficult requires fine co-ordination between steering and braking. The concept however IS simple. Brake hard, slowly let of the brake as you increase steering angle. At the apex, you'll have max steering lock and zero brake pedal depression.

b) It can be used in high speed turns, albeit you'll not brake all the way to the apex.

c) Regarding the weight transfer scenario, you WILL put more weight on the front, but the TRANSFER of weight from front to rear will be more gradual, especially if you trail brake all the way to the apex, thereby causing less disturbance to your car.

d) There is no reason to NOT use trail braking in an oversteery car. However, trail braking makes best use of tyres if the car is NEUTRAL

e) Trail braking is used to go faster everywhere

[Mashed]

Trail braking is a simple technique to get the rear end of the vehicle to rotate for the corner. For obvious reasons, it transfers more weight to the front of the car thus making the rear of the car light and easy to rotate before turning in for the corner. Hope that makes sense. Basically the technique is used with cars that tend to understeer and/or on real sharp corners.

A bit late to the party I see

Yeah sorry, I just didn't feel like reading through 8 pages to see if someone got it right.

I'm afraid you dont know what this technique actually is used for.

a) It's not simple...

Are we talking about trail braking only in F1 or in general for any level of racing?

Your right with point A. My explanation was to get the idea/concept out there while you described it in more detail.

[flmkane]

What is your understanding of the difference between trail braking in F1 and racing in general?

[Jersey Tom]

Trail braking is a simple technique to get the rear end of the vehicle to rotate for the corner. For obvious reasons, it transfers more weight to the front of the car thus making the rear of the car light and easy to rotate before turning in for the corner. Hope that makes sense. Basically the technique is used with cars that tend to understeer and/or on real sharp corners.

I can't agree with this statement. One of the side-effects of trail braking is that it can free the balance up on the brakes (though not always - could just as well put a very aggressive decel ramp on a ramp & clutch diff, or heavy forward brake bias, and get trailing brake understeer). And yes, that can be advantageous.. however, fundamentally the concept is to use the combined capability of the tires to brake later in a corner and make for better lap time, rather than to just use it as a handling/balance crutch. That is true on all levels of racing.

[Belatti]

Regarding the tyres that "can only do one thing at a time" I remember reading an article about Alex Zanardi hard time getting to grips with the Williams. The problem was grooved tyres of the time. They did not admit Alex trailbraking and he could not adapt to a more stop/start "V" shaped trajectory style.

[Jersey Tom]

Regarding the tyres that "can only do one thing at a time" I remember reading an article about Alex Zanardi hard time getting to grips with the Williams. The problem was grooved tyres of the time. They did not admit Alex trailbraking and he could not adapt to a more stop/start "V" shaped trajectory style.

There are times drivers say such things, yes.

[raymondu999]

There were people who have said the same of the 2011 and 2012 Pirellis though - rubbish under compound loading (both axles)

[Lycoming]

Trail braking is a simple technique to get the rear end of the vehicle to rotate for the corner. For obvious reasons, it transfers more weight to the front of the car thus making the rear of the car light and easy to rotate before turning in for the corner. Hope that makes sense. Basically the technique is used with cars that tend to understeer and/or on real sharp corners.

It transfers more weight to the front of the car compared to what, not braking at all, or full braking?

[raymondu999]

I think he means rather than braking early, and then holding a constant wide arc through the speed (ie the F3 carry-speed style, rather than a trail-braked corner)

[thisisatest]

i searched but couldnt find it, but somewhere out there is a great diagram showing a vehicle trail braking into a corner using vectors to illustrate its benefits over the "classical" line and technique. im sure the book i read was big, in-depth, well regarded, popular, if that helps.
traction circle plot over time in a trail braking scenario vs. brake-first-then-turn is very illustrative as well. you basically can spend the maximum amount of time near the edge of the traction circle in trail braking.

[Ciro Pabón]

Excuse me for interrupting, but where is trail braking used in racing? I mean, except in motorcycles, spec races and rallies?

In bikes trail braking is a necessity (you will lean easier). In rallies, well... it goes without saying. In spec races the differences are so small and the power so low that only trail brakers can win.

Please, do not mention the word "drift". Drifting is not racing.

On racing cars there is a huge problem: mistakes with this "technique" are ugly and you will not win more than one or two car lengths if you get it right.

Trail braking and consistency are opposites.

When you get it wrong (and, believe me, it's soooo easy to get it wrong!) you end with a car that has the wrong angle in the entry, so you will get a immediate taste of what the car does when it's understeering/oversteering. Some people call it the "pop quiz" of the car.

You will miss the apex, get the gravel and come back into the track.

May the gods of racing help you.

(Your adversaries will not be happy, btw, when they see you blowing the apex, panicking, hitting the barrier and coming across the track at the exit. That's NOT the place where you want to make mistakes).

When I see people trail braking (except when we're talking of a desperate driver, a biker, a dirty road driver or a spec specialist) I move from my marshalling position to a very protected site. I do not want a car coming for me from any unpredictable angle.

Frankly, I see a lot of BS in this thread, if I'm allowed to put it in this way.

Trail braking is the signature of simulator aficionados, if you ask me.

Real drivers look for rear bias to tap the brakes, not to loosen the rear axle, but to settle the rear axle, á lá Schumacher.

Period.

[timbo]

Excuse me for interrupting, but where is trail braking used in racing? I mean, except in motorcycles, spec races and rallies?

So, is F1 a spec race? Gotta be...

[raymondu999]

Ciro - surely in a series where every tenth counts - they'd trail brake? I mean, they'd probably do it in qualifying. We always see it on pole laps. But not in races? Really?

[timbo]

Ciro - surely in a series where every tenth counts - they'd trail brake? I mean, they'd probably do it in qualifying. We always see it on pole laps. But not in races? Really?

I think if we had a way to see the telemetry of the whole race, we'd see that when they are saving tyres they brake more in straight lines.
One thing to note -- trail braking is not something like heel-n-toe, the extent of trail braking can vary. Just how close to the apex you go off brakes may vary.

[Jersey Tom]

Excuse me for interrupting, but where is trail braking used in racing? I mean, except in motorcycles, spec races and rallies?

Oh I dunno, everywhere. I don't know of any road racing series (or any series really) where you can be fast by braking only in a straight line. Not talking about giving up hundreths here - more like tenths or whole seconds.

Trail braking is the signature of simulator aficionados, if you ask me.

Real drivers look for rear bias to tap the brakes, not to loosen the rear axle, but to settle the rear axle, á lá Schumacher.

Period.

Schumacher himself would disagree, as does his DAQ. Does this not look familiar? Extreme trail braking in action.