atb

Chris wrote:
Hey, even if we don't get to go on the track, do we still get to BBQ?

Dave wrote:
It just walked through the door.

Adam C. wrote:
That one will have to wait Adam, I'm not driving the car today. They aren't as pretty, I've had them on for awhile already. Regarding the stroker, I'll start a new thread. I've got some questions to pose to the group.

shaark89wrote:
They are stock twin turbo rear calipers. The second photo shows the machining that needed to be done to fit the rear of the S4. Essentially, its an S4 front caliper that has mounts to fit on the back.

Dennis K wrote:
Thanks for the heads up Dennis. I'm running the 33 now. Garth H. was running the same set up with the 33, and liked the 55 better. We'll see how it goes. If the 55 is too much I can pop the 33 back in. With the A/T, I think I will probably like the 55, we'll see though.

bd0nalds0n wrote:
I don't really ever get into the ABS when I'm on the track. With the Big Reds on the front, running the stock 18 bar valve, I was constantly locking up the fronts with hardly any braking to the rear. It made all of the braking zones quite the handful, front tires howling, fighting the wheel, etc. The 33 cleaned it up pretty nicely. I'm curious as to what the 55 will do.

Ketchmi

The calipers are modified to fit S4's and the rotors are a Porsche stock item for 993TT's. I have run with the 33 bar and much prefer the 55 bar if you are all out gonzo racing. I thought the stock S4 brakes were good until I played with a set of TT's on all 4's with a 55 bar. With stock tires, the 55 bar may be a bit twitchy, with good rubber, WOW do they stop!

blau928

Dave you should try a set of big reds with Pagid Orange and D Compound slicks.... In the dry of course and after warming up the pads...

Anchor come to mind...?

Dennis K

Dave - just be aware that sticky tires will cause a need for less rear bias. The grippier the rubber, the more weight will transfer to the front wheels. With the front wheels more heavily loaded, a greater percentage of your total braking force will be available from the fronts. THe rears will play less and less of a role as tire grip increases.

On a separate note, I hope Miller Motorsports Park in Salt Lake opens as promised this year. That track is going to be a monster and I'd make the trek from CA just to drive it. Maybe I'll see you out there!

Ketchmi

We are looking into having a 928 day in 2006 at Miller Motorsports Park. It will be a serious road course with24 corners and 4.5 miles of fun. We just attended a meeting with Larry Miller & Assoc. last thursday to get the details, simply WOW! It will be one killer track with elevation changes and one off-camber corner just to keep people on their toes. Wide open run off areas to minimize any car damage from off road excursions and 50' wide in most places. It is actually two 2.25 mile courses that can be run at the same time or combined for the monster. It will even have Grand Prix style pits that open onto the grid area but no Formula 1 races will probably be held there due to the lack of golden toilet seats for Bernie E.

I'm sure we can help you get on the track if you are serious. Just let us know when.......

Dennis K

I've been to the track's website and it is going to be an amazing place. I can't wait for it to open. That's so great that you've been able talk to the principals about it. New tracks can be like new software - lots of hype then non-existent.

When you do the 928 day, I'll be more than happy to help out and instruct.

slate blue

Well I also have 993 twin turbo brakes front and rear, so nah nah na nah! Just kidding, but because of that I have cosiderable experience in getting the balance right. Please bare in mind that every car will be abit different due to different weights. So when I talk I talk about my S2, manual transmision (remember engine braking) with bilstein shocks and 225 P Zeros on the front and 285 P Zeros on the rear.

I tried the following combinations, standard S2 master cylinder. This was hopeless, locking the fronts way to early, this was with a 33 bar bias valve.

Then I went to an S4 master cylinder as it has more rear brake capacity, still locks the fronts way too early with the same bias valve.

I then go and get a 23 mm all the way through master cylinder, 33 bar bias valve, still locks the front brakes too early, starting to get pissed off now.

Remove the bias valve altogether, it then locks the rears, huray! Now I know I'm getting close, fit a 55 bias valve, there is a 60 bar one available, and it will lock the fronts first but just feels rock solid. Pedal has great feel, remember larger master cylinder and I have the small booster, also all brake hoses replaced. Pedal is firm and well weighted. 100 to 0 times around 3 seconds dead.

Hope this helps, I really feel you will need another master cylinder though.

drnick

very interesting greg, where does your master cylinder come from?

slate blue

It is a Porsche item I believe it is from the pre S2 cars and was fitted to the 928 when they fitted bigger brakes roughly back in 1980.

Tom in Austin

Interesting to hear of someone using Big Reds on the rear ... everywhere I've seen kits they were for the front.

Anwyay, knowing this is possible, would anyone like my extra 993 TT rear rotors? I bought a complete four-wheel Big Red package (used for 1,500 miles, all very clean and straight) and sold off the rear calipers, but haven't found any takers for the rear rotors. I think these things go for about $150 each new, and I really need to make some space in the garage, so am open to most any offer if someone would like to put them on their shark.

Fastest928

Dennis, wow, you have been running those brakes for quite some time now! I agree ... having first implemented this combination on the 928, as well as using and selling this kit ..

OK engineers, what is wrong with this picture?

Wear Glasses as your eyeballs might pop out under hard braking...

Have fun

aircooler

Hi Mark,

Do you have any damaged S4 front covers, or pieces there of?

I am looking for this small area from the left side.



If you don't have this scrap now, would you be so kind as to keep me in mind the next time you see a damaged cover?

Many thanks,
Mike

fst951

Hi Marc,

As a fellow mechanical engineer, I don't understand the reference to the picture. Give me a little insight.

Thanks.

atb

Maybe that I'm showing a left rotor with a right caliper? (quicker turn in )