Brake Balance Question

Perhaps a cockpit brake bias control.

 

Nope, you are spot on.

 

I suggest running, not walking, away as fast as possible.

The reason you want brake power biased to the front is because that is where all the weight is under braking.

More Weight on the front wheels = better grip on the front tires, which results in a greater amount of brake pressure needed before locking up = more stopping power = ability to go even deeper into turns = time saved.

Also, when your brake bias is adjusted to the rear, the weight of the vehicle is unable to transfer as far forward, which reduces the relative grip on the front tires, which means you cannot turn in as effectively, which means you have to slow down more under braking, which means you have to back your braking zone up, which means... etc etc.

Having brake biased to the rear is not only slowing you down, its just not safe.

 

1+

You never EVER want the rear brakes to lock up first except when doing J turns in a wet parking lot. Becuase of the wieght transfer most of the braking is done with the front wheels. Becuase of that the rear end of the car wants to swap around. Fortunatly the rear tires are still in contact with the road to keep the rear end steering straight. As soon as those rear tires lock up they are no longer steering the back end of the car and the ass end will go out in whatever direction it wants without much warning. Under hard braking the rear wheels are barely touching the ground as it is.

I'm sure you have seen the guys in the movies driving the car in reverse and spinning the car so they can throw it in drive and go? Almost all cars have much bigger front brakes since the front does most of the work. When you are traveling backwards you now have these big brakes on what is now the back of the car and they will lock up first causing the car to swap ends. If you find a good open space and get up some speed in reverse, pop the car in neutral, then slam on the brakes the car will pretty much spin around by itself. If you don't put it in neutral the trans will be very unhappy. I don't think this will work with an ABS equiped car.

Racers will adjust the brake bias according to track conditions. On a wet day for instance you will not have as much transfer under braking so we will dial the brake bias towards the rear a little. We start out with the bias on the front brakes and slowly adjust more to the rear brakes until the rears start to lock up under hard braking. At that point we adjust it back to the front a little and stop there.

 

I run ABS cars and my scca class I don't even thing allows brake biasing. But I see it a bit different. I want the front to lock first if given a choice but ABS always prevents that. I want as much rear bias as I can get but absolutely no lockup there. You may voluteer to buy the brake pads for your team and then do something like run carbotech xp10's in front and xp8's in the rear which will give you more front bite and more even brake temps since the rear never get as hot as the front. You could find such a mismatch very pleasant since race pads like to work at the right temps and feel real good when they are at the right temp. You can use the templique paint from pegasus racing to experiment with what temps you can get your pads to.

 

Tell that guy to have some confidence in the car and take his foot of the brake and the car will steer through the turn instead of plowing straight into the wall. I know this is easier said than done but it is very often the case. Get to understand the "Friction Circle" and how it comes into play in a situation like this. Take your foot off the brake a little and start turning the wheel. You'll have so much loading from the wieght transfer the car will turn in very nicely. If your using all the available traction for braking you have none left for turning.

 

2nd that. This is not a team you want to be part of. You never EVER want the rears to lock up first.

 

Everyone here responding has it spot on. In general, if a car has ABS, you can play with pad compounds but that's about it(well unless you buy a programmable motorsports ABS unit, but then you need to know how to tune it!). With no ABS you almost always need to pull the factory prop valve and run an adjustable. Lowering, sticky tires, spring rate changes, tire diameter changes, track temps and moisture etc etc all change how much rear brake the car can handle. Plus 30 year old prop valves are probably not as sensitive as there were when new. Alfa's pass under braking, gotta make the most of it, unless you've got the 400hp South African 3.7l stroker monster...
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wow, amazing photo

 

There are good reasons for brake proportion fore and aft. The ideal feel is to have the front and rear threshold lock at the same time every lap. While a track is rubbering in and fuel is burning off the only way to manage this is with an onboard bias control.

Premature lock in the front requires shorter a braking distance and is easier to control but after a few laps it can make for too much front tire wear and adversley affect initial turn in.

Premature lock in the rear is a good way to conserve front tires but makes swapping ends very easy.

http://www.youtube.com/watch?v=VMugB5TZ0BI

Too much rear brake!

 

That's one bada$$ V-6 motor...

 

Agree you are spot on. Play with brake pad grip coefficient if you can not manually bias.

 

I think you people can find the best answers on many after market upgrade parts providers and at several websites.