Quattro4lifeAus

I'm posting this hear as it is a good bet many of you tacke you car to the track and have been doing so longer than i.

Do we need a Mater Cylinder Brace?

When braking if i'm not feeling the abs then i know i'm not braking hard or late enough for a corner and after a couple of hot laps i'm standing on the thing for the thing for the corners.

Yes i have upgraded brakes and yes when they need replacing i will upgrade to something porsche.

What i am concerned about is the firewall flex (if any) for the B5's. Surely repetitive had braking is going to place strain on the firewall.

Correct me if i'm wrong - which i hope i am.

Has anyone ever had the need to fit one of it is just dead weight?

Thanx in advance.

urS4guy

I run 993tt Big Reds front and rear on my urS4. The rear calipers are sized a little smaller than the fronts as are the pads. The front rotors are 323x32 drilled 993tt 2 piece. The rears are 314x30 drilled 2 piece with custom hats. The set has stainless steel lines all around and uses a WRC dedicated master cylinder for emergency brake activation. The braking on this 3685lb, actual dry weight corner balanced car, is awesome. Fade is also nonexistant at the track. You will not need a master cylinder brace. HTH.

Hap, talkin da kine brakin from Evahboost

ryoung

It's easy enough to check. Start the car, have someone watch the nose of the M/C, and push as hard on the brake pedal as you would when braking for Road America's Turn 5.

On the A8/S8, the master cylinder will move forward about 1/2". With more than a 4.5:1 pedal ratio, that means the brake pedal does absolutely nothing while moving about 2-1/2". Whether street or track, <a href="https://forums.audiworld.com/a8/msgs/38595.phtml">The Block</a> makes an absolutely huge improvement in pedal feel.

<img src="http://pictureposter.audiworld.com/17157/TheBlock.jpg">

ModifiedA4

it sounded like that the real problem was lose bolts/nuts holding the cylinder down?

ryoung

From the engine compartment side, I can see the top two nuts for the pedal assembly bracket, and they're tight. I can't check the bottom two without either removing the master cylinder and vacuum booster, or disassembling part of the underside of the dash to check from the inside, but ...

With every '01 or later A8 and S8 I've checked, the master cylinder moves a bunch with heavy brake pedal effort. I think the pedal assembly, master cylinder, and vacuum booster are just bolted to a flimsy firewall.

AntiSocial

Problem solved.

ryoung

Weld the M/C or pedal assembly to ... what?

AntiSocial

Never have to worry about it again.

:-)

ModifiedA4

ahh ok...the linked thread is confusing on that issue.

ryoung

I can't easily get at (or even see) the two bottom firewall/pedal assembly bolts, but I can't imagine that these are loose on every A8/S8 made since 2001 (or at least every A8/S8 that I've sat in and pushed the brake pedal).