Willard Bridgham 3

I run a modified turbo S with stock brakes and stock cooling ducts and have not had any problems braking even on fast tracks.

You have a problem other than brake size that should be fixed.

Giacomo

In line with some of the other commentary, the S4 brakes should be more than adequate, even at the stock weight and at a track like WGI. If you are requiring daily flushes I would investigate fluid, pads and cooling prior to investing in a brake upgrade or you may have the same result with the new setup. I have gone to the S4 fronts on my 968 F class (these were the M030 option) with no problems and I have yet to duct in cooling. This advice presumes you are building a relatively mildly boosted 951, if you plan to build a 400+hp monster then that changes things. If you plan to PCA race in the stock classes, also consider that any brake caliper set that was not available as a factory option on that model will put you up a class and in my opinion, not do anything to help your lap times. Larger brakes also add unsprung weight so there is no advantage to installing more brakes than necessary.

HansB

Interesting.
When I bought my car in 2002, the PO had put on them Big Red Front, and Big Blacks Rear. I stripped it down to sub 2400.

All of my racing buddies told me what many people here say: this was overdone, and the standard brakes should be enough. They would maintain this, until they would enter a turn together with me during a race: They got outbraked. Over and over again.

Now everybody drives BR/BB or BR/BR and alas, I have lost my advantage.

RICHVIZZ951

I ran a pretty highly developed 951, 400rwhp, lighter than yours, etc etc, 928 brakes or big blacks just did Not cut it for me. halfway thru a 30min sprint race they would get spongy and required a double pump at times.

Went with early cup brakes, AWESOME, For a 90 minute enduro has Zero fade and can just about out brake everything. Takes a bit of getting used too cause you can go so much deeper, kinda like throwing out a boat anchor when you stand on them.

Pricey but one of the best mods I did to car..

renvagn

Amen Hans +++++1

Thanks for all the constructive advice. For those who don't know, this is a meticulously maintained, strong car. Drover needed. As stated earlier, new rotors, Motul, rebuilt calipers, fresh pagid Blacks and pedal travel all over the place, sometimes pumping up with my left foot.
Trying to hang with the contemporary fast metal out of Stuttgart, with my 3,235pound package, the brakes and heat generated just aren't cutting it.

I have access to a used nose to cut up for the ducts and big blacks look like the option to go with.

Rich.....Out of curiousity what cup brakes did you go with? And you are smoking fast by the way.

Oddjob

You having fading problems after 15-20 minutes into the run sessions, or nearly right away? Fading/pedal travel the only symptom?

Shouldnt have major braking issues with your setup. I would look for a problem, before upgrading.

Have you replaced the master cylinder? Have the problem before and after rebuilding the calipers? The car does not have ABS? So no ABS hydraulic unit, right? When swapping out brake components, and with as much bleeding as you have tried, its real easy to trap a lot of air in the system, and you need to ensure that its all flushed out.

renvagn

Jim,
Fading pedal is the situation. I agree with the traped air and have gone through 5 quarts of fluid this season since March. Master cylinder is untouched and we haven't noticed any external leaks. I do understand that the internal failure is often a problem. Didn't notice the problem prior to this year. The rear were rebuilt over the winter and the fronts done a month ago. I use a pressure bleeder and often have someone put some lite preasure on the brakes to get a better bleed. My ABS is still installed and working.

Oddjob

Is the pedal softer than it should be even when the car is shut off? On track, do you have fade right away? Or is the pedal effort/travel, and braking power fine for the first 15-20 minutes of a session, and then starts to fade?

If the pedal is always soft/fading, and if you didnt have the problem prior to this year, then that would indicate something is not right.

The seals on the master cylinder pistons can wearout/fail, allowing blow-by, so the symptoms would be a soft pedal, a lot of pedal travel, and not a lot of brake force. But I would not go swapping that out right away.

Due to the ABS hydraulic unit, and less direct brake line routing, ABS cars are a lot more prone to trapping air in the system. Do you get any lock-up with the ABS? If you do have some lockup, somewhat more than just a chirp at low speeds, that is likely air in the hydraulic unit.

smankow

Mark, are you certain that you've gotten ALL of the ATE out of the system? that also could cause a problem

smlporsche

I have the 928 S4 binders on the front of my car and have never had a problem braking.
I do have the original OGracing ducts that fit into the driving lights and go to the Broadfoot racing adapter at the rotors.
One of the best mods I've made on the car.
I can post a pic tonight when I get home if you'd like to see them.

renvagn

Eddie,
Thanks in advance for the pic. I am making plans for ducting as this excess heat has allways been an issue. This year at Mid ohio a session was black flaged and we had to sit on an uneven surface in pit out, which required me to have my foot lightly on the brakes. I smoked my fluide and had to pit. I am good for 3-4 laps and I start to get a long pedal. Also 6 days on pagid blacks and I am cooking them pretty good. I would guess 3 more days and there gone.

renvagn

Steve,
2 quarts of motul. Not SRF but more $$$$$ than Type 200.

daigo

I'm running Big Blacks (928 GTS) on the front. I've also nade my own backing plates as I didn't like the Broadfoot units. They don't contain the air into the eye of the rotor where its most effective.




I'm going to feed the backing plates with the OG intakes that replace the original brake ducts in the bumper. These are 3" as opposed to the units that replace the foglamps as they are only 2"

renvagn

very nice Daigo. the design looks more efficient than the adaptor Lindsey racing sells. How hard were they to make? Do you have the measurements available.

Lemming

Agreed, those backing plates look great