jaholmes

I recently steped up to some Hawk HP Plus brake pads for track use and I am running P-Zero Roso's. The rear tires are almost gone so I will be looking for new tires soon, fronts still have a lot on them. I would like to do another set of rear's before I change all 4 out. This is on a C4S. Not sure how to ask the question but it seems that the brakes are over-braking the tires to the point where the grip from the tires is gone. I am not loosing control but it seems the stoping distance is longer now with this combination. Obviously the ABS is kicking in. Before I was running OE brake pads with the P-Zero's.

Is this the way it is for high performance street tires. Is there a better track tire / track pad combination then what I have or am I smokin something.

Would there be a difference between the P-Zero's and say Michelin Pilot Sport (RIB). I can't do the PS2's because they do not come in 285's. Unless 295's will fit on 10 inch rims. The MPS-Cups are another option but I am not sure I am ready for DOT-R and the other issues that come with them. I also don't think I can get the negative camber for the MPSC's to work right. I still have the stock SUV suspension.

Thanks,

techno99

How old are your tires? Are the fronts and back the same age? If they've been tracked before, how many heat cycles to the tires have?

DJF1

So you noticed the change when you changed the pads? It is true that this is the feeling you get when the ABS kicks in. You are going to feel exactly the same way with race tires on and full on racing suspension...I feel it exactly the same way with my race car. The key here is to learn threshold braking, when you feel the ABS kicking in, back off slightly to the point of max deceleration just before the ABS kicks in.
I would suggest spending money on your suspension before you move to the MPSC's.

jaholmes

Thanks for the help. Maybe I noticed it more now then before. I think when you do any mods you are hyper sensitive to the changes. I need to find the right threshold braking. I think I am pushing it more with the new brakes then before with the OE brakes.

My tires aren't that old. They were brand new when I got the car a year or so ago and I have maybe 3k miles.

I do have a set of JIC Coilovers ready to go but I can not decide on the proper spring rates. The ones I have are 10k and 14k. Definately a stiff suspension. I would like to lighten it up but can't find good advice on what to do. I would like to start with 7k and 10k springs. Maybe something a little more firm then and M030 setup. I also have to replace the front control arms. Some say press them out and put in ERP's, I would rather go with RS arms.

Funny thing the MPSC's are cheaper then the damn P-Zero roso's.

Bill Verburg

JIC 7/10 are definitely much firmer than M030

I have JIC 7/10, TRG bars, RS rotors & calipers, Pagid RS19 pads, MPSC 225/40 & 265/35. It's a very nice setup especially on rough pavement

For street use definitly use the RS A arms

jaholmes

Bill,
I keep referring back to your build and your use of 7k and 10k springs. I got the JIC's for the price of a Bilstein setup so it was a no brainer to go with the JIC's. Also, from what JIC says, the 7k/10k is their soft setup. And I only need to get the 7k springs.

BTW, what are the differences between RS rotors and normal Big Reds. I would like to get away from the drilled rotors I have and get slotted ones.

Bill Verburg

7/10 are JIC's softest but are far from soft

stock 993 uses 1 piece 304x32 & 299x24 drilled & ventillated rotors, w/ the med large front and small rear Brembo 4 piston calipers

993RS uses 2 piece front 322x32 and 1 piece rear 322x28 drilled and vented rotors w/ large front and med large rear calipers(aka Big Reds)

To get away from drilled rotors use the 993RS/tt hats w/ an aftermarket rotor, nothing you can do about the back unless you are willing to give up parking brake.

More brake info here

Greg H.

Bill -

That is interesting: The rear disk of a 993 TT/RS/C4S is larger than the front disk of a 993 C2, but the same pad is used.

Greg H.

Bill Verburg

That's correct, the 993RS/TT/C4S all use the same rear pads as a normal 993 uses on the front, the rotors are taller but thinner than the normal 993 front

CWay27

Slightly OT

Just like my buddy's Cayman S front calipers are same as a 996 GT3 rears.