Hi Chuck. You're right on. As if Porsche would sell their cars with
marginal brakes... The stock brakes are able to lock up all four tires
on dry pavement at any speed. That's why they have ABS to *limit*
the power delivered by the brakes.
To improve street braking you need to first ensure the wheel
alignment is close to optimal, so the tires are level under braking,
especially the front wheels. The other main factor is the stickiness
of the tire.
Bigger brakes will do *zero* in the street except the placebo
effect and the fact that the brakes were bled and refluided when
they were changed. Bigger brakes (in the case of most Porsches)
will only help under high heat repeated braking like at a track
event, and it's often cheaper and just effective to just get more
cooling air to the stock disks.
Joe

 

Joe I agree on some of that but when you have 700plus HP the stock brakes don't seem quite so hot anymore. There are a lot of "street" level kits that really are just that. The GTR's are a SERIOUS step up both in terms of repeated braking at the track but even in terms of slowing a heavy 996TT down that's travelling way quicker than a stock TT. We've got two shoot outs that show teh GTR's are far better on the track but also in general 100-0 or 60-0 stops.

 

can you post the numbers? or do i have to dig up the archives?

when i stop by, i'll try your GTRs....

- chuck

 

I'll go home and find 'em in excellence... basically, fred's with GTR's was top, mine was 2nd or 3rd (I forgot?) with GTRs as well (but no ABS/PSM lol).

 

stop tech SS lines

 

Thanks for all the info guys, it is appreciated. it's important to me to have independent opinions before I go to my dealer.

 

Maybe its just me but no car I ever drove on the track with stock brakes lasted more than 3-4 laps before they started fading.....

200+ miles on the last track day and the GTR's were bulletproof...I faded long before the brakes ...

 

I can't honestly compare the stock to to the Stoptechs because I switched them out when I did the engine mods...all I know is the stoptechs were noticably better dealing with 600+ HP than the stock brakes were with 415. If you don't want to spend alot of money but want to upgrade they are definately a good option.

Good brakes are almost as much fun as more HP

 

Ajax, I'd agree.. the more HP you throw at a car you have to have some balance with suspension, brakes etc... Seriously, ask anyone that's driven my car, as impressed by the acceleration that they are they are just as impressed by the GTR brakes stopping force....

 

Sure. On the track the repeated braking is so hard that the brakes
never get a chance to cool so the fluid boils. Bigger brakes (and/or
better air delivery to the discs) allows the heat to dissipate quicker
so there's no fade. No one can put that level of thermal stress on
the brakes however hard they drive in the street.
The first good cheap step if you're going to track a 996tt is to get the
GT3 plastic air diverters that attach to the front lower control arms,
instead fo the smaller stock ones. I know of track junkies that never
have problems with their 996tts on track after that.
Having a fresh fluid and bleed is also a good idea. If the bigger brakes
are also lighter than the stock ones, that's a good benefit in more than
one way.
I still contend that for any single max-brake stop from 190mph to zero,
the stock brakes will never be any problem, and if you want to stop
better in those circumstances, focus on the traction between tire and
road. If there is thirty seconds or more of driving before this is repeated,
the stock brakes will have cooled enough to repeat the performance.
In any more challenging situation like track events where there's hard
braking every 5-10 seconds, you need more cooling, whether by more
air and/or more surface area. Air is much cheaper.
You can make the system feel firmer by removing flex/expansion in
the hoses by using stiffer steel-braided lines, but often the feel
improvement is from fresh fluid.
Joe

 

Joe since you're local you're welcome anytime to try out a set of GTR brakes with 245/335 RA-1s. At least on my car you can and I'm sure some of the other local folks would oblige on their rides. Theories are sound but again in this instance you just haven't tried these. There are about 5-6 GTR-based cars (yes with a lot of power) that stop better than any 996TT with stock brakes on the street. They obviously all have brake cooling ducts. Again, in both shoot outs every single car that had GTR brakes out-stopped any stock brake system period. Whether it was on the track, during 90-0 or 0-100-0 tests.... 5-6 laps with Cort Wagner at Buttonwill at the first shoot out I remember two cars with stock brakes fading and then the car scooting off into the dust. The PCCB's were on fire too- which wasn't funny (GEN 1s). Not so the GTRs... And the basic tests going from 90-0 also showed otherwise.

If there was no way to improve upon the 996TT brake system why did Porsche try the ceramic way? They also used a larger caliper (from Brembo) housing more pistons and a larger rotor. I'm not saying those PCCBs are my cup of tea but there is always room for improvement- beyond the weight savings too.

The NorCal bunch who all have around 700HP and those GTRs certainly didn't do it for looks or bling... there are plenty of other "big red" calipers etc... one could use for that purpose. These are light weight and true racing brakes that could be considered overkill for the street but they do also work and work well in that situation.

I don't go to the track as often as I should or would like to- instead I actually end up driving way too many modded GT2s and TTs. Some have stock brakes and some have GTRs etc... Honestly, in my humble experience of driving these everyday I'm not kidding you when I say there is a very noticeable difference between the two in terms of stopping...

 

I also felt my Brembo Gran Turismo 14" brakes were alot better then my stock 996TT brakes as well, but different car and totally different setups. Even my turbo with Pagid Yellow's and motul superblue fluid was a huge difference from stock, so many different setups you can do ranging from just changing fluids, brake lines and pads with stock rotors and calipers, upgrading rotors and everything keeping stock calipers or fully changing everything out, you have tons of options!

Goodluck.

 

[quote=sharkster]Joe since you're local you're welcome anytime to try out a set of GTR brakes with 245/335 RA-1s. At least on my car you can and I'm sure some of the other local folks would oblige on their rides.
[\quote]

You are always a generous man, and I would love to visit some time to
experience better going and stopping.

[quote]Theories are sound but again in this instance you just haven't tried these. There are about 5-6 GTR-based cars (yes with a lot of power) that stop better than any 996TT with stock brakes on the street. They obviously all have brake cooling ducts. Again, in both shoot outs every single car that had GTR brakes out-stopped any stock brake system period. Whether it was on the track, during 90-0 or 0-100-0 tests.... 5-6 laps with Cort Wagner at Buttonwill at the first shoot out I remember two cars with stock brakes fading and then the car scooting off into the dust.
[\quote]

Interesting. I might have expected lap-running to show stock fade,
but if alignment, suspension, tires, and vehicle weight were the same
I would have guessed that single XXX=0 runs would not have differed.

[quote] The PCCB's were on fire too- which wasn't funny (GEN 1s). Not so the GTRs... And the basic tests going from 90-0 also showed otherwise.
[\quote]

PCCBs on fire? Yow. Never heard that before. I guess the stock
iron brakes are equal to the GTRs in flame resistence...

[quote]
If there was no way to improve upon the 996TT brake system why did Porsche try the ceramic way? They also used a larger caliper (from Brembo) housing more pistons and a larger rotor. I'm not saying those PCCBs are my cup of tea but there is always room for improvement- beyond the weight savings too.
[\quote]

Well, yes, the GTRs are certainly better than stock. I'm just thinking
that for most people, the added capability will never be tapped. Porsche
and all of us are always interested in improving things. The PCCBs
main promise were weight reduction and durability. They do wonderfully
at the first bit, and overpromised on the second.

[quote]
The NorCal bunch who all have around 700HP and those GTRs certainly didn't do it for looks or bling... there are plenty of other "big red" calipers etc... one could use for that purpose. These are light weight and true racing brakes that could be considered overkill for the street but they do also work and work well in that situation.[\quote]

Some day I would like lighter brakes myself. I understand that most folks
who upgrade their brakes do it intending to improve braking safety or
performance. Just count me as a crank that still harbours the notion that
most of them get the main gains in the placebo area.

[quote]
I don't go to the track as often as I should or would like to- instead I actually end up driving way too many modded GT2s and TTs.[\quote]

I feel for you, man. Something to do with your lifestyle.

I can't argue with your experiences. And if/when the brake fairy offers
me a wish, you're local so I know where to get them. If I had all the
money, I'd ask you to retrofit me with gen II PCCBs. If I had some of
the money, a bigger+lighter set would be cool too. I have to prioritize
stuff, and tires are my main money-sinks nowadays. Maybe I just don't
drive fast enough to need better brakes (no joke), and I'm over generalizing.
You know I specialize at the street-speed stuff.
Joe

 

My pleasure Joe- seriously if we could convince you then we know they work

Lap running did show a lot of fade- now not every car was the same in terms of power and suspension but the tires were all PSC for the first shoot out and RA-1 s for the second. You can see Cort's comments on the brakes in the article. As for the fire comment.. Cort pulled in jumped out of the car to get into the next one and we all saw smoke billowing out from the wheels of the ByDesign car (with PCCBs) that he just got out of. The editor then shouts, "Hey Cort, did you know that car is on fire?". I have no idea what pads they chose to run but no kidding...

I couldn't agree more- hence not my cup of tea. Interstingly enough, the GTR caliper (both 8 and 4 piston) are super light and way lighter than the PCCB ones. The rotors aren't as light but not much heavier so any reduction in weight is almost matched by the GTRs. I also agree for most people stock is a-ok...


Doing what you do it wouldn't be a bad idea actually... I'm not sure what the rules/regs are for that sort of thing though. Being cranky is just fine- I am that way too. I don't believe anything till I see, try and test it- or have others that are better drivers test it for me (since I'm a wuss).


I know man it's ironic I don't get to go more but hey.. I do live vicariously through some of these nutters cars we work on On your car and scenario there are plenty of cheaper, more efficient ways of ekeing more performance out of it. In terms of the PCCBs, no joke but there might be a set soon available because the owner of a TT wants to swap to GTRs.... Might be a month or so but I'll keep ya posted!