I have already made the decision to go with 18" HRE 540Rs (due in about 2 weeks) so that I can run race rubber. Unfortunately, that limits me somewhat in terms of available brake upgrades. Here are some options:

1. Brembo 14" rotors F/R, 4 piston calipers. They cost about the same as the 15" upgrade, or $6500 or so. (The LeMans kit does not come in a 14" rotor.)

2. GT3 front rotors. 350mm up front vs. 330 mm for the turbo. Same at the rear. Not sure off hand what the cost is.

3. 1" larger diameter rotors from perfect power, which utilize the stock calipers. They run about $1,570 for the set.

Ideally, I'd like to improve braking power to the extent possible, retain the ABS functionality, and also reduce unsprung weight. Any ideas for which of the above options is best? Alternatively, I'm open to other ideas?

One other idea worth considering is whether there is a lighter weight, and equally durable, rear rotor... again, for reduced unsprung weight.

Thanks in advance,
-Donn

 

Are you absolutely sure that you cannot fit the 15" Brembos on the front? As I posted earlier I did it with 18" Fikse wheels.

John

 

Well, not absolutely certain. Todd at EVO is going to do some measurements for me once the wheels arrive. There is some chance that the 15s will fit.

Did you go with the LeMans kit or the Evolution kit?

-Donn

 

I believe it was the LeMans kit.

 

On this topic, I wonder if a modified 996TT even needs a brake upgrade. For example Ruf does not appear to have modified the stock brakes one iota...

 

John - pics of your brakes please...I am interested in seeing how the le mans looks on a car....what color is your TT anyway?? TIA

 

The 14" evolution kit from Brembo and the 15" LeMans kit will fit under 18" wheels but the 8 pistion 15" kit need 19" wheels but I am not 100% sure, you might just might be able to squeze them under a 18" wheel. I am wouldn't try though. IMHO. But also the stock brakes are equal to 1100 HP.

 

Your last sentence kind of speaks to one of my concerns. Does anyone have any hard data that says that the Brembos improve braking performance over the stockers in non racing applications? The larger rotors should help to dissipate heat better in road racing applications. But, I don't intend to road race the car. So, will the Brembos actually stop the car any quicker in street and or back roads driving? Basically, does anyone have data that says Brembos stop the car from 100-0 in x.xx seconds vs. the stockers which do it in y.yy seconds?

-Donn

 

Racer 63
I'm not sure I understand what your looking for.

Stopping faster is only a funtion of getting the brakes into ABS zone. Once this happens, your car will not stop noticably faster with bigger or smaller brakes. The stock brakes will certainly do this.

I know you know this but, if you wanted to track the car, (without ABS) there would certainly be modulation differences and feel, and very big difference with cooling, thermal absorption and dissipation, etc. but these things are irrelevent on street driving (in the US, anywhere near legal speeds).

There is no pressure factor with the stock brakes and thermal fade should not be a factor if your sane, and even then, more cooling would be preferred the answer, not bigger pistons or disks.

 

btw, does anyone here actually did a comparsion between the turbo stock brake, GT3's (PCCB is not my option ) & the aftermarket brake like Brembo upgrade?

the stock is good enough IMO. i just want a yellow look up to this point.

i was pleased even with the C2 brake when i was in Porsche Driving Experience. they never give up.

 

Don't have any hard data, but suspect the answer to your question is NO. I believe the limiting factor affecting the shortest distance (fastest) stop for a one-stop trial would be the tires. In situations of sustained and frequent hard braking, the upgraded systems will tolerate more heat (and transfer less heat to the brake fluid) resulting in longer fade-free/confidence-inspiring braking. Of course, the floating hat two-piece rotors on the upgraded systems save a significant amount of unsprung weight, which is a good thing.

 

the biggest reason to change to the Le Mans series (or PCCB - if they were worth a crap) is to reduce unsprung weight. fwiw, i noticed a decrease in braking when going to the tt brakes on my c2 since the brakes were designed for the larger contact patches of the tt. iow, my limits of adhesion were being reached earlier thereby triggering abs earlier. i moved up to a tire with more traction (bf goodrich kd) which remedied that problem. given i increased unsprung weight, i now realize it was the least productive and most detrimental performance modification i've thus far made.

 

Definitely an advantage. I was talking to several brake suppliers and it sounds like the primary weight savings is in the rotors themselves - not the calipers. So, that's why I'm considering replacing rotors only...

 

if i'm not mistaken, you can't just replace the rotors (which are indeed most of the weight savings). i wanted to do the same thing, but brembo said it can't be done without replacing the calipers too. i wonder if putting on the lighter brakes reduces the heavy feel of the awd?

 

I'm trying to get more info on this. But, here's what I know so far.

Perfect Power claims to have 1" larger diameter rotors which utilize the stock calipers. They run about $1,570 for the set. Trying to find out the weight though...