Braking and turning in - Trail Braking

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andylaurence
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Re: Braking and turning in - Trail Braking

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Ciro Pabón wrote:That's why people that knows better do not use trail braking unless:

a. You race bikes
b. You race in the dirt
c. You're in a spec series
d. You're in dire need of a car length and you don't mind if you ruin the weekend
e. You want to win.

It's faster. Books on racing techniques tell you to do it, racing instructors tell you to do it, the best drivers in the world do it and my data logger says it's faster when I do it.

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Ciro Pabón
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Re: Braking and turning in - Trail Braking

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http://phors.locost7.info/phors23.htm
...

- it's a small effect compared to the big-picture basics, like carrying speed out of a corner, that everyone must learn early on
- it's difficult to learn
- mistakes with it are ugly

... exceeding the limits at trail braking has some of the worst consequences one can invite on a race track, typically worse than those from mistakes at corner exit. It's definitely a big risk for a small effect, justified only because it accumulates. Blowing it results in too high an entry speed... However, when the cars are equalized, as in spec races, showroom stock, or in a lot of Solo II car classes, trail braking takes a prominent role.
Some cars just hate trail braking. Like Formula Type cars, at least in real life. They tend to understeer when the brakes are on.

Trail braking is not the fastest technique, but all do it.
Ciro

timbo
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Re: Braking and turning in - Trail Braking

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Ciro Pabón wrote:Some cars just hate trail braking. Like Formula Type cars, at least in real life. They tend to understeer when the brakes are on.
That would depend on brake bias, don't you think?
Ciro Pabón wrote:Trail braking is not the fastest technique, but all do it.
I fail to see how it isn't fastest, for example the link you provided says otherwise. It might not provide enough benefit if you have a car with a very forward brake bias and tyres which don't work well at combined loads.

Jersey Tom
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Re: Braking and turning in - Trail Braking

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Ciro Pabón wrote:Trail braking is not the fastest technique, but all do it.
Do tell then.. why does every professional driver do it if it's slow.
Grip is a four letter word. All opinions are my own and not those of current or previous employers.

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raymondu999
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Re: Braking and turning in - Trail Braking

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Interesting feature in Autosport about Super Touring. Here's an excerpt from an interview with Alain Menu
Q: What's the technique in fast corners? Is a front-wheel-drive Super Tourer different to a single-seater?
A: I would say it's not that different. In a single-seater you don't want to turn in on the brakes, and the same in a touring car. You have to have it all sorted out before you turn in.
失败者找理由,成功者找方法

marcush.
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Re: Braking and turning in - Trail Braking

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I think the discussion is based on wrong assumptions -
first of all you cannot and will not need to build instant cornering force .
second cornering is not about maintaing the highest g-forces but corner with the car "flat" as long as possible..So why not aim the car towards the turning point under brakes ?
Needless to say a car under full braking force will not turn in ,but this is not trail braking .
as i understand the real specialists have a very special ways to attack corners ,using the brakes also to position the car for a no sideforce corner exit surely not good for apex speed but that is not so important with high power ratios .
You also gain an advantage by covering less distance over a lap with that approach.

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Tim.Wright
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Re: Braking and turning in - Trail Braking

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Alain Menu wrote:Q: What's the technique in fast corners? Is a front-wheel-drive Super Tourer different to a single-seater?
A: I would say it's not that different
Have to say, I stopped paying attention at this point.
Not the engineer at Force India

Jersey Tom
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Re: Braking and turning in - Trail Braking

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Tim.Wright wrote:
Alain Menu wrote:Q: What's the technique in fast corners? Is a front-wheel-drive Super Tourer different to a single-seater?
A: I would say it's not that different
Have to say, I stopped paying attention at this point.
It's a pretty blanket statement he makes for sure, but there's some truth to it. Regardless of platform I'd think you would want some precision on entry of high speed corners... wouldn't be bad to have some power-on understeer (either with FWD or RWD) in that case, rather than smashing the brakes on turn-in for a hairpin when you really want some rotation.
Grip is a four letter word. All opinions are my own and not those of current or previous employers.

timbo
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Re: Braking and turning in - Trail Braking

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What is high-speed corner in F1?
If it is something like Copse, than unless the track is wet no brakes are used at all -- just a lift-off and the drag does the rest and doesn't unsettle the car.
If we talk something Stowe-fast, than usual trail-braking is used.

flmkane
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Re: Braking and turning in - Trail Braking

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Jersey Tom wrote:
It's a pretty blanket statement he makes for sure, but there's some truth to it. Regardless of platform I'd think you would want some precision on entry of high speed corners... wouldn't be bad to have some power-on understeer (either with FWD or RWD) in that case, rather than smashing the brakes on turn-in for a hairpin when you really want some rotation.
Trail braking is not the same as 'smashing the brakes'.

Trail braking relies on the driver being able to modulates the brakes such that the longitudinal braking force gradually decreases, as the lateral forces increase. Therefore at max longitudinal force, lateral force is zero and vice versa.

This means that the trail braking technique requires a driver to smoothly bleed pressure of the brakes while turning the steering wheel.

Neither does train braking imply understeer of any form, if the brake balance is set correctly. With proper brake biasing, as the tyres would be at their limit simultaneously, so no under or oversteer would occur if the driver is smooth and precise. In fact, if the brake bias is to far aft, then there would be oversteer due to tyre slip angles at the rear exceeding those at the front

Jersey Tom
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Re: Braking and turning in - Trail Braking

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Sure. Point still is that high speed entry is a different beast than low speed as far as how and when you want your yaw response to be... and that there are at least conceptual similarities to how one would approach a high speed corner in different types of cars.

Much the same as low speed corner entry is the same between different types of cars - you T/B it.
Grip is a four letter word. All opinions are my own and not those of current or previous employers.

marcush.
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Re: Braking and turning in - Trail Braking

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I´d think a formula 1 driver has to be an extreme expert in brake force modulation anyways ,as the grip levels cease dramatically with slowing down as you shed downforce .
Is there even much room for trailbraking under these circumstances or is it simply a case of not early enough off the brakes and your inside front will send a puff of smoke?

timbo
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Re: Braking and turning in - Trail Braking

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marcush. wrote:I´d think a formula 1 driver has to be an extreme expert in brake force modulation anyways ,as the grip levels cease dramatically with slowing down as you shed downforce .
Is there even much room for trailbraking under these circumstances or is it simply a case of not early enough off the brakes and your inside front will send a puff of smoke?
Pretty sure there is. On various real telemetry traces on the web there's very little time a driver is not using either throttle or brake. Can't imagine that'd be the case if people were coasting much.
Although I have to note that on some of the fast laps drivers seem to actually coast, although not for long.

Diff-user
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Re: Braking and turning in - Trail Braking

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I would assume that trail braking would show up as a near circular arc of g-force indicator so often shown with on-board laps. In this context check out any of the laps posted on youtube, as an exapmle see the video below.... fast forward to the braking point of spoon curve to see what i am talking about.

[youtube]http://www.youtube.com/watch?v=VnXt-gBIhWc[/youtube]

Isn't that trail braking?
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engines are there just for the sound
V10.......V8.......V6....... V none
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marcush.
marcush.
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Re: Braking and turning in - Trail Braking

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nah.. wrong driver.He was just not good enough ... :mrgreen:

of course you have ,it was a amateur question really .we do not understand what really talented people can do and coordinate .
I´m sure I could not control this.