Trail Braking?

[dtype38]

Originally Posted by Austinspace75

Anyway, regarding straight line braking, its by far the most efficient way to scrub off speed because you are using all of your potential.... you're just using it all for braking that's all (as long as you're braking to the threshold of course).

Yup, agree with that. I think the flaw in the argument in favour of trail braking over straight line braking is that it assumes the speed at the end of the braking zone is the same in both cases. In actuality, straight line braking is shorter and ends at a higher speed because at turn in all of the available grip is being passed to cornering.

Of course, the skill with getting the best out of the straight line method is to minimise the time between getting off the brakes and turning into the corner. That very much depends on how much the car dives under braking and how smoothly you can transfer the weight off the front end. As previously said, this would favour a stiff car as the transition can be much quicker.

Overall I think possibly the two techniques both have advantages and disadvantages, but it very much depends the setup of a particular car and the areas of confidence of the driver as to which will ultimately give results on the time sheet.

One thing's for sure, it makes for interesting racing when you're bumper to bumper with someone using the other technique!

[tristancliffe]

I can't believe that anyone waits until their foot is off the brake pedal before moving the steering wheel. I'm sure that even 'straight line brakers' still start to turn as they come off the brakes, overlapping the two ever so slightly - and that is trail braking. Some cars need to be braked in a straight line for a lot longer before the overlap occurs, whilst others can start turning whilst still quite heavily into the braking zone (driving style will also play it's part too of course). But both are trail braking.

I'd love to see some datalogging from someone who states they never do that!

[davyboy]

Originally Posted by tristancliffe

I can't believe that anyone waits until their foot is off the brake pedal before moving the steering wheel. I'm sure that even 'straight line brakers' still start to turn as they come off the brakes, overlapping the two ever so slightly - and that is trail braking. Some cars need to be braked in a straight line for a lot longer before the overlap occurs, whilst others can start turning whilst still quite heavily into the braking zone (driving style will also play it's part too of course). But both are trail braking.

I'd love to see some datalogging from someone who states they never do that!

Kart racing's probably the purist form of driving... we modulate the brake, throttle and steering to get through a corner. The concept of 'finishing your braking before beginning your turn in' is not something I'd ever consider in the dry.

[dtype38]

Originally Posted by tristancliffe

I'd love to see some datalogging from someone who states they never do that!

If you classify starting to turn the wheel just before getting fully off the brakes as trail-braking then yes I do that sometimes, but certainly not always. I guess I do it more when I've left my braking later than intended but even then I'd be just as likely to over-rotate the car and scrub speed off that way instead. I'm also not saying that I never trail brake. It's particularly useful when overtaking up the inside into a tight corner, but then the objective is track position, not minimum lap time.

I'm struggling to describe the feel of it, but the best example I can think of is the first corner at Snetterton. I line up on the left on approach and brake hard, short and dead straight, just inside the white line. I then come fully off the brakes and turn in aiming to miss the first visible apex by a good car width. The turn in is at quite high speed, and from that point I use my finger tips and bum to gently encourage the car to rotate gradually more as the corner progresses. So for about the first third of the corner I'm not braking or accelerating, I'm just using all the grip available to rotate the car. As soon as I'm satisfied I've got the position of the car right I start easing back on the power, and by the middle of the corner I'm aiming back towards the inside of the track and firmly back on the throttle. The objective is to be on full throttle well before the true apex near the end of the corner, with a view to maximising exit speed onto the short straight. The second corner is then just a mini version of the first, with the emphasis always on getting on full power as early as possible, and on a line that means it can be kept fully on right through the exit of the corner.

All that said, it doesn't work for the first corner at Donnington. Ok, I admit it... I trail brake that one!

[tristancliffe]

Riches (the first turn at Snett) is a funny one, as is Sears to an extent. For Riches in my car (a trick I learnt watching onboard footage of British F3) I brake in a straight line, and then open the throttle as I turn - by the first apex I'm already back at full throttle if everything has gone to plan.

At the other end of the lap - Russell chicane - everyone trail brakes into that, and shouldn't be off the pedal until they're on the first apex, using the brakes to rotate the car allowing a much earlier throttle application onto the pit straight.

It does depend on the corner!

[terence]

I would agree with most of whats been said,apart from Trailing into Russell.
Why should braking technique differ from one corner to the next? All of the preparation for any corner is the same.The usual mistake for many drivers is to attack Russell,trail braking often is the cause of the corner being totally cocked up,with the car being only just under control,often out of!
A very good friend asked where they might find another 1.5 seconds,after watching his progress in practice I suggested that he get his braking done before turning in and not running either side of the kerbing,a habit that many seem to be taking up thanks to the poor driving seen in BTCC these days!.His result from Russell alone found him his 1.5 plus a little extra from using 4th instead of changing into third for Riches.Trail braking,as I have already said,is fine for those who cannot get it all done before they should have and have a.b.s fitted.[I should add that said friend is no novice]

[tristancliffe]

Originally Posted by terence bower

Why should braking technique differ from one corner to the next?

Because every corner is different, and requires different techniques and compromises, and different cars have different braking, accelerative and cornering abilities.

Russells - The first part (the right hander) is actually bloody quick - the only reason it's a slow corner is because of the really tight left. So it makes sense to brake for the left hander up to the left hander, and as such trail braking through the right hander works well. This applies to both the F3 car I drive, and the Lancia Fulvia I used to drive (on trackdays).

What about the Esses - a certain place for trail braking if ever there was one. Slowing from over 100mph whilst turning left...

[Chris Y]

Certainly with racing a 2CV around Snetterton (and we do it for 24hrs so we get time to practice these things ) you trail brake into the first part of Russell. If you don't, then you're off the brakes and just slowly plodding through it until you reach the turn-in point for the left hander. With a low-powered car, you just can't afford to spend too much time off the loud pedal.

However, for Riches corner, you tend to brake in a straight line until turn-in. Mind you, we don't do too much in the way of braking for that particular corner.

At the Esses, the tendancy is to brake all the way up to the turn-in point for the right hander, but it depends so much on the set up of the car. A lot of the cars carry some trailing throttle through the left hander in order to keep the back end from overtaking the front end! Some brake in a straight line before the turn-in, then 'square up' the corner before braking some more for the right-hander. Again, all depends on stability of the setup, and confidence of the driver.

[GORDON STREETER]

Come of it Chris, I wouldn't have thought you need brakes on a 2 CV !

[terence]

Originally Posted by GORDON STREETER

Come of it Chris, I wouldn't have thought you need brakes on a 2 CV !

You beat me to that Gordon.

[JamesH]

I find myself sort of agreeing with tristan (now there's a first).

The Esses are a prime example of trail braking potential. Not so sure about Russells though.

[JamesH]

Originally Posted by GORDON STREETER

Come of it Chris, I wouldn't have thought you need brakes on a 2 CV !

Team Stinky could have done with them at Russells - would have stopped then smashing in to me and b***ering our race!

Amazing that just a caved in rear arch pushing on the wheel could not be over come by the engine. Not much power there!

[Chris Y]

I wasn't driving at that time, so I can't really comment on what happened there. Sounds like you got an extra bit of trail braking from the rear though!

[wordup]

Hi Guys,

I've managed to find a great little article on trail braking on the track day drivers website.

I hope this helps!

[NJH]

Sorry to bring this one back up from the dead but there is a superb article by Mark Hales on this subject area in this months Track Driver mag.