333pg333

The new setup will be similar to some of you guys:

All OEM parts pretty much gone. Replaced by Tilton pedal box w/ dual m/c and adj bias ****.

Front brakes will be 350mm Giro disk with floating 2 piece CEP hats and adapters. 997 Cup Callipers.
Rears brakes will be 298mm (I think) Giro floaters CEP hats / adapters. Mo30 Callipers.

I'm going to stick with PFC 01 / 97 for now but am curious about how this is all going to react. ie Much lighter stiffer car with more mechanical grip and power. Not sure if this is going to be more prone to lockup or not? Guess loosing the booster should help eliminate lockup?

disasterman

That is a pro setup. Looking forward to hearing your experience with it.

xschop

I just finished the prototype adapter that mounts the billet Dynapro's to the rear of the 944 and 928 to match the Wilwood front Cayenne 330 rotor kits for both cars. Pads and piston sizes galore....

Lemming

Agreed, the DTC-70's are great, albeit very noisy. I run DTC-60's on the rear, 70 would be too much bite for me on the back. I'm still running Turbo S fronts and turbo fronts, in the rear. Master cylinders are 5/8F 3/4 rear.

333pg333

So when I last drove the car it was about 3000lbs. It had Big Reds front with PFC 01's and Mo30 rears with PFC 97s.
Had all the OEM hardware plus s/s lines, SRF fluid, floating slotted rotors.
As this was in a non ABS car I found that I was getting lockup and flat spotting tyres from time to time. As anyone who has done this, it's a real pain in the ***. Both financially and can ruin the day at the track.

So now with some obvious changes being the new brake system as mentioned above and the car down to what I guess will be around 2600lb with half a tank of E85 I am wondering if the extra lightness means that with the same brake setup as before, would I have experienced a higher chance of lockup or lower? In my mind I think that the lighter car needs less brakes...but then the car will be travelling quite a bit faster out of turns therefore faster down the straights and faster coming into the braking area. Thoughts?

Dubai944

You will have to drive it to see what your new combo produces. If it's is setup properly, the dual master and lack of booster should allow you a much more precise pedal for controlling lock up. You will probably need to push a lot harder though!

Front to rear bias will have an effect on how controllable lock-up is as well. You might have had a tendancy to lock fronts previously because your pads biased things too far to the front using the softer 97s in the back. When I had stockM030 calipers all round I found the bias with the same pads front and rear, and 5/33 proportioning valve to be pretty good. You need to make the rears work and the stock M030 rear calipers are small enough to need to run the same pads as the front. Different story for those bolting old front calipers to rear. Now you have bigger piston area in the back relative to the front and may have to use a softer pad back there, as in Tim's example. Relative pad grip front to rear plays a big part in bias and controllability as well.

Lemming

Patrick,

Make sure that you give yourself enough time to dial in the setup before your first important event. Getting the bias setup properly takes time, as will getting used to the manual brake setup. Just remember, if you are not stopping PUSH HARDER!

The other thing you will have to work on is your heel/toe. The fact that you are putting more force into the brake pedal means that h/t is not as simple. For me it is curing the bad habit of downshifting too soon under really hard braking. But it also means that your pedal setup needs to be spot on (should be easy with the tilton setup).

Dubai944

Ideally you need some time doing some repeated straight line braking practise with an older set of tyres that still have even wear but that you can afford to risk flat spotting, gradually adjusting the bias to the rear till you just start to lock the rears then backing it off a bit. Helps to have someone trackside to tell you visually what is happening.

333pg333

Some great advice there guys. When in doubt..."PUSH HARDER!!" lol...

In context with all this of course I was a very interested onlooker to see what Tony experienced from his new brake and Boxter ABS setup. (I'd love the Bosch M/sport abs but each time I go back to the tree and shake it, less leaves seem to fall.)
I was discussing this with the engineer (when he stops work to talk he has a lot of experience and is fascinating to listen to) and he thought there might be some potential considerations vis a vis the Boxter abs, but conceded that if it works it's very tempting dollar wise. However he made me feel more assured by explaining one of the features of all the electric whizzbangery that we've installed is that you can gear a pre-set % of wheel speed differential into the Motec SLM and then you can have it light up in a certain position on the display (even either side to mirror the car) when you are going into lockup. This gives you a warning that you can modulate out of and still make the upcoming corner. Instead of the past where I've come into a particular turn, suddenly started to lock..then flatspot my way through the corner and into the sand/dirt/grass etc... So I'm stoked to have this early warning system available. Of course it will be another thing to setup and learn but at least it's there. The same wheel speed differential (except on acceleration) will be used for traction control also.

More than just a shift light: http://www.motec.com/slm/slmoverview/

Not the perfect video but gives you some ideas of what it can do.

Dubai944

Hmm, sounds good in theory...

Does it have a light to tell you you are just going way too #$%@ fast to make the corner locked or not?

333pg333

Yes, that's the lights from the Ambo!!!

MC 968CS

Pat, happy to help you out as an observer or whatever. MAC

333pg333

Thanks Mark. There's still a way to go yet but it's getting closer each week.

disasterman

Ditto Lemmings comments about about bad habits while downshifting. I know that will be my first challenge. If you look at data from most club drivers you will find a slight lift when they blip the throttle.

That Motec system also affords you traction control!

333pg333

Just trying to figure out quite what you mean about lifting while blipping the throttle? Do you mean brake pressure? Obviously part of the heel and toe is blipping with the accelerator which of course moves down and up. So I guess you mean during the blip, the pressure is coming off the brake instead of it being a more continuous motion?

Yes, traction control noted in #54. That will something else to figure out.