Hm, just a thought. Multiple brake pedals?

[lark_demon]

I was thinking about if there were multiple brake pedals on a car, a person circuit racing with very fine precision could specifically brake certain rotors to optimize the turning capacity of the car? More effective brake distribution I suppose?

For example:
There would be 2 pedals instead of just one, and lets say the left controlled the left side and the right controlled the right side.

Making a hard left turn, instead of completely braking all of the wheels, you could brake the left side harder so that the right would have more grip on the outside.

Or maybe, it could be more precise with pedals on a swivel in the middle going forward and back, controlling all four rotors independently.


Hm, they already have eletronic programs that do all this stuff I'm sure, I just thought I'd propose something interesing.


Who doesn't like a challenge?




-mav

[caddydaddy]

Kind of like how the Rally car racers use the e-brake to corner better. I guess you could rig that up to a pedal!

[curtis73]

On a four-wheeled car, that would just induce instability and spinouts. You want equal braking, or the car will just lose control. True, if you brake just on the left, the car will pull to the left, but it should never be assumed that it would help cornering.

In a race turn, you need to enter it at a speed that maximizes weight transfer without losing control. You maintain a steady-state max speed turn and then accelerate exponentially as you exit the turn. Braking is a waste. The bottom line is that you are attempting to push the chassis and tires to the limit. Brakes won't do anything but screw you up. If you are at the limit of a turn, braking the inside tires will cause the car to yaw which will do two things; increase the slip angle of all four tires, and offset the weight balance to the inside. Increasing the slip angle (since you're already at the tire's limit) will induce a loss of traction. Removing weight from the outside tires will also reduce their peak grip. In a nutshell, what you would be doing is achieving max cornering velocity, then applying the inside brakes would be the equivalent of a PIT maneuver like you see on COPS where they just tap the rear fender sending the coke-addict into a wall.

I think you're confusing how individual braking can help things turn in a closer arc; like tractors and off-road rock crawlers. On a race car, it would just be suicide

[Polygon]

This is exactly what stability management systems do. While it is great for helping morons stay out of a ditch it will not make a professional faster. An unskilled driver could use it as a band aide I suppose. Also, a computer is much better at controlling that then you could. It would be an interesting idea, but it just isn't feasible.

[GreyGoose006]

since i dont feel like reading curtis' post, i will say what i want and hope it isnt exactly what curtis said.

when making a hard right turn and braking at the same time, especially braking hard, the front left wheel will be the first to lock up.

the inner front wheel will always have the least grip, breaking wise, because it is also trying to turn the car. when this happens, you will begin to understeer.

the inner rear wheel will lock up next, and when this happens you get lots of oversteer.
in the case of a car with anything other than an open differential, this will tend to cause the outer rear wheel to lock up, worsening the oversteer condition.



ideally, you would have a computer that allowed you to mash the brakes as hard as you could and the computer would distribute braking force to each wheel individually, preventing each wheel from locking while allowing for the fastest possible turn, which would probably mean some braking induced oversteer.

however...

this does tend to take the challenge out of racing, so i cant see it being implemented on anything other than possibly F1 applications




edit:
this all applies to a situation where the driver brakes while the car is contiuning straight, then begins to turn the car while the brakes are still being used...
A.K.A trail braking

[Polygon]

Like I said, what you're referring to is ASC. It is great for tool bags that don't know how to handle a corner but you can be faster without it. A great example is the SRT-4 Caliber. It uses a system like this in place of an LSD. Let's just say I've yet to hear one good comment about the system. The only car I can think of that uses ASC very well is the EVO.

[KiwiBacon]

I have seen pictures of a racing cars pedal box with two brake pedals. But nowhere did it mention which way the braking was split (i.e. left/right or front/back).

Many rally cars have adjustable brake bias on the fly, but I've never seen one on TV pull the handbrake into a corner. I do however know people who've rolled their cars attempting such a maneuvre.

[Moppie]

Originally Posted by KiwiBacon

Many rally cars have adjustable brake bias on the fly, but I've never seen one on TV pull the handbrake into a corner. I do however know people who've rolled their cars attempting such a maneuvre.

Watch some in car footage from any WRC tarmac rally.
They have the handbrake level specially extended so it's with in finger reach from the steering wheel and yank on it at every slow speed corner they get to.