hans14914

Stuart: I have a set of those calipers sitting on the shelf - I am very interested in the rotors you used to get that setup. I found that the CP555 series calipers have the same offset as the GTS calipers, so curious if you were able to keep the stock spindle, or if you had to modify it as well.

Frank: 993TT or Big Reds have the same dimensions and are essentially the same casting (different part numbers) as the GTS or big blacks. They are just mounted in a different configuration, so you need to swap the crossover tubes, like rotating tires, on the calipers, so the bleeders end up on the correct side of the caliper for the 928. I have heard from many experts that the 993TT calipers work much better.... because they are red.

Franks928s

NOW - that's "Hot!!" What's on the rear?

Frank

Franks928s

love it Believe it or not...my prefrence for color is actually the black ones

stuartph

Andrew


At todays rate it was $3840

Custom parts are the alloy bells and brackets to hold the calipers plus brake lines

Hans

The disc's used are CP5772 1080GA LH/RH 356mm x 32mm

Stock spindles

Frank

Stock on the rear at the moment but will go for 330mm disc's and 4 pot AP's next year

Lizard928

Frank,
unless you are going radical with tires etc. I would just recommend installing S4 suspension and brakes and be done with it.
Most will have trouble justifying the extra expense of going up to the next size. And the S4 still have more than enough grip

blown 87

I actually found the limit of mine on that last mountain drive we had, Mintex pads, drilled Zimmermans (Will go solid next time) and brake fluid less than 5 weeks old, have the factory dampners installed and about 80% left on the pads.
That was the first time I have ever got brake fade, not sure if it was the pads or the fluid or both.
Not a good feeling at all, and I was not really pushing them that hard or so I thought.
That 993 was hard for me to keep up with though.

Lizard928

Greg,

That is a different limit we speak of.

Boiling the fluid, and overheating the pads is due to a lack of proper cooling.
A real problem on the S4 imo.

The limit I speak of is the ability to engage ABS with a smooth application of the pedal from speed. I have found that the stock S4 setup is good (on street tires up to 245 front) up to and around 75mph.
Past that you could possibly use slightly more.

However if you went to a more aggressive pad (personally find the mintex to be a bad pad), and put in some good brake fluid that problem would disappear. I use Wilwood 575, its a DOT 5.1 and works great.
The other thing to do is to add some more ventilation to the brakes.

blown 87

I have ordered some ATA brake fluid and I know I need better pads on it, I just can not stand squeal.

What can be done about the cooling of them, every thing is there from the factory.

mickster

I thought cross-drilled cooled faster than solid discs, no? You said you wanted to switch from drilled to solid.

blown 87

Lots of discussion on that, it may have been needed when the pads were not what they are today because of gassing.
I am not sure about the cooling, but it does take away from the effective swept area.
I put them on cause they look better IMHO

mark kibort

its not a track car, so you are doing it for bling factor. you might be going a little faster and might want better feel, so the larger diameter rotor is the way to go. you can do this with stock calipers, WHICH by the way, is the same size that most of the top exotic cars, and many race cars use. (ie stoptech ST40s use the same pad as the S4 caliper and that is used on many pro race cars) the diameter is what sucks on the S4, and that is an easy fix as was mentioned. spacers (cheap) and grinding a little on the ends of the caliper to accept the larger diameter rotor.

brake fluid. just use super blue and dont give it too much thought (all the racing fluids are near the same and work well. no big deal if you change fluid often anyway and boiling points are similar. I have NO braking issues and never had with the s4 and stock ventilation and cooling. just recently put on stainless lines, as my rubber ones blew a hole and almost or could have cost me the car. (too old).

drilled vs slotted vs solid. Ive done all 3. slotted will work near best, because the holed rotors crack, during track use. however, if you dont track it, holed is best and look the best in my opinion. solids work find and Im using them now, as I cant find GTS or 964Turbo rotors that have slots. another nice thing, the rotors are cheap. actually , im using someone elses used rotors that I turned. they are the longest living rotors Ive used to date. no cracking or warping after almost a full season of racing.

hans14914

You can always use titanium pad spacers to reduce the ammount of heatsoak from the caliper bodies into the pads. Stoptech and RacersEdge both have 928 friendly titanium spacers.

Also, the Motul fluid is a much higher performing product for not a lot more money, most notable is the high "wet" boiling point. You can get it lots of places, including Amazon if you are lazy:

http://www.amazon.com/Motul-RBF-Raci.../dp/B000AURZ08

Just some quick fixes.

blown 87

I guess you would have to drive the road we were on to know what it was like, pretty much corner into a corner, second gear at most, not really going fast, but a lot of hard acceleration and heavy braking.
I suspect that your road courses are done at a MUCH higher speed.
I really think that 180 in North Georgia is better than the Dragon.

blown 87

Quick and cheap is good, no way am I going to spend thousands on slightly better brakes.
I will get some of that for the next time I change fluid, is that a dot 5.1?
I loved the comment in the add about it is better in the rain.

AO

Greg, I think the problem is the pads you are using. Those Mintex pads do not work well IMO. You need to step up to the Hawk Performance Plus pads. HUGE difference. They don't last as long, makes lots of dust, but don't squeal much and they STOP your car!