optimum disc sizes

[WabTheKing]

i understand what your saying, all tho i dont beleve my driving to be good enough to warrent such a system, plus i know far to little about the behavor of a car on a track to start playing with it like that, this is basicly for a road set up that is used on the odd track day

[A1QSHIP]

Woha! I did not mean to question your abilities. So sorry if it came out that way, my apologies. I too drive a coupe with the NA 7b engine. What I am saying is the bias valve is used to calibrate the brake bias & that this bias will change with how much fuel is in the tank. I autocross my car with the stock brake system on the vehicle. I have driven it with the anti-lock off & with it on. Right now, I have no reason to want to change the bias but when the brake system is changed to larger components I know how to change the bias if necessary. ANY modifications done to a car necessitate learning how these changes affect handling & braking.
Chris

[WabTheKing]

no no no mate know you werent questoning, sorry just read back what i replyed sorry, i know that you wernt saying that, im gonna have a look where to put this valve tonight, have edited the above so it reads right - sorry again

[auditude]

Woha! I did not mean to question your abilities. So sorry if it came out that way, my apologies. I too drive a coupe with the NA 7b engine. What I am saying is the bias valve is used to calibrate the brake bias & that this bias will change with how much fuel is in the tank. I autocross my car with the stock brake system on the vehicle. I have driven it with the anti-lock off & with it on. Right now, I have no reason to want to change the bias but when the brake system is changed to larger components I know how to change the bias if necessary. ANY modifications done to a car necessitate learning how these changes affect handling & braking.
Chris

As for the dynamic valve that changes the ratio based on axle load/position, I call those proportioning valves. I don't know if that distinction is one between the adjustable but fixed ratio bias valve, and the variable ratio (somewhat adjustable) proportioning valve, or if they are considered the same thing.

Anyway, when we/you are discussing adjust the bias for modified brakes, would a car have both types of valves installed, the original one (if it exists) that changes based on axle position, and the new one to be used to compensate for the brake system mods?

[WabTheKing]

as i understand it, this replaces the "standard" setup

[auditude]

as i understand it, this replaces the "standard" setup

Hmm. Ok, so do the Wilwood and similar replacements also take into account the axle position, or does it go from an automatic system to one that would require manual adjustment for full tank/passengers/luggage/etc?

In other words, would it actually be a downgrade to replace the stock one with the Wilwood one, as far it would no longer compensate for changes in load distribution/axle position? (Aside from the idea that the stock bias/range is not optimal for modified brakes.)

I'm just curious, so if I'm not making sense, feel free to ignore me!

[WabTheKing]

dont know that the standard one would take that into account, i think its just a pre-set bias valve set by audi, which would explane why pembo's rally car has a very twichy **** end when braking, the loss of weight from the car being stripped out has not been compensated for, there fore making the rear wheels lock up prior to the front ones, often resulting in a spin!!!

[kwlw]

dont know that the standard one would take that into account, i think its just a pre-set bias valve set by audi, which would explane why pembo's rally car has a very twichy **** end when braking, the loss of weight from the car being stripped out has not been compensated for, there fore making the rear wheels lock up prior to the front ones, often resulting in a spin!!!

Making your rear brakes more sensitive - you get more stopping power. Also you get more risk. I have several friends, who moved balance more to the rear. One of them rolled his rally car when testing the settings ... Another - is very satisfied with the settings, and claims, that his car tiny brakes never fade. Maybe its also related to driving and braking style.

In my plans there is also adjustable brake bias valve, however I think, that I will start to mess with in on the brake stand first.

Sau