GT PP brakes for the track

[D K]

Hi

are the pp brakes up for the task?
I'm talking about changing fluid and replacing the rotors with 2 piece rotors - are the calipers up for the job??

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[Crowd Hunter]

I would also like to know.

 

[strengthrehab]

Simply....yes

 

[D K]

not simply?

Simply....yes

 

[fatbillybob]

The PP1 brembos in my 2019 GT racecar work OK. I'm running big brake deflectors like Vorschlag ones, 295 square hoosiers, XP20 carbotechs, 2 piece rotors I forget the brand and SS brake lines. This car is heavy! I do not have the initial bite I like nor the modulation I had with Stoptech 4 caliper SCCA T1 kit that stoptech developed on my C5Z06. I would not want the S550 brakes to be any worse. I'm on the limit of what I would consider acceptable. I hope that going to XP24's will improve the braking performance a bit. I'm glad that I'm racing an A10 thus left foot braking. I do not think I would like these brakes with my style of heel toe downshift and sliding over to LFB. I think the best heeltoe is done with precise pedal positions...at least it is easier for me. The brake pedal on the S550 is unpredicatable in feel. I like high initial bite, controled weight transfer, and then pedal to hit a wall at threshold (a reproducible poistion) that allows precise throttle blip. Then when I slide my left foot to brake my braking does not change vs. having to fiddle with a somewhat mushy S550 peddle as I transfer feet and maintain brake pressure...and no there is no air in my lines nor boiling of fluid. But yeah the car stops OK

 

[Grintch]

not simply?

Depends on the track, the driver, and your setup.

If you have slicks, a blower, a pro driver, and need to slow from 190 tp 30 at the end of a long straight you will need more brakes than a stock car, driven by a average driver, on a tight course.

Stock brakes have proven adequate for me (club racer) even running R compounds (NT-01s) at tight tracks like Barber and TGPR with good & fresh brake fluid. For a faster track like Road Atlanta or Road America I would probably want track oriented pads or extra cooling (or I might have to just be easier on the brakes in my driving technique). Similarly if I switched to stickier Hoosier R7 tires and a more aggressive suspension setup, I would expect I would need to upgrade over stock.

Caliper and rotors seem to be fine for most track rats, with just pad and cooling upgrades for even serious cars, drivers, and tracks. 2 piece rotors are a useful upgrade, but are not really needed IMHO for HPDE and significantly increases your consumables cost.

 

[D K]

When I mentioned ‘stock’, I was only referring to the calipers.
rotors and fluid would get replaced no matter what.

I am not a pro driver, but I am always on the limit of brakes seems like.

I definitely want the option of running 18” wheels, so gt350 brakes are out.....

The pp calipers look stout, but I anted to hear from track people.

I dont know the mounting arrangement, but if there was room to move the calipers out a little and use bigger rotors, that would help also but then again, im. Not sure how much space there is before you hit the wheel..

If pp calipers with good, 2 piece rotors and aggressive track pads and fluid along with ducts are good enough, I will be very happy...

Does anyone know if the gt350 master cylinder is bigger in diameter, *and* if the abs calibration is different?

Thank you

Depends on the track, the driver, and your setup.

If you have slicks, a blower, a pro driver, and need to slow from 190 tp 30 at the end of a long straight you will need more brakes than a stock car, driven by a average driver, on a tight course.

Stock brakes have proven adequate for me (club racer) even running R compounds (NT-01s) at tight tracks like Barber and TGPR with good & fresh brake fluid. For a faster track like Road Atlanta or Road America I would probably want track oriented pads or extra cooling (or I might have to just be easier on the brakes in my driving technique). Similarly if I switched to stickier Hoosier R7 tires and a more aggressive suspension setup, I would expect I would need to upgrade over stock.

Caliper and rotors seem to be fine for most track rats, with just pad and cooling upgrades for even serious cars, drivers, and tracks. 2 piece rotors are a useful upgrade, but are not really needed IMHO for HPDE and significantly increases your consumables cost.

 

[NeverSatisfied]

Hi

are the pp brakes up for the task?
I'm talking about changing fluid and replacing the rotors with 2 piece rotors - are the calipers up for the job??

GLOC R18/R12 Front/Rear Pads
Titanium pad shims
OEM Rotors
Motul 660
SS lines
Vorshlag air deflectors

On 305mm square Cup2's or 200TW RS4's with stock power, once I addressed all the drivetrain cooling issues, I've found the limit is overheating the tires. If I really crack the whip, the tires go greasy before I can induce brake fade.

I could see potentially finding OEM brake limit on race rubber.

If you're sticking with street rubber, I wouldn't stray from OEM rotors. Just throw a set on every time you burn through pads (which this car is pretty good at doing quickly). On slicks, I'd still give the OEM setup a shot before upgrading. It's not the best but it's pretty darn good.

 

[nbjeeptj]

They do a good job, however I find the life of the dust boots to be low ( I have found that those are available at Rock auto). I dont know what other options you would have that did not cost $7,000.00 for front and back. Looks like AP racing makes a caliper that would not have the dust boot problem, but I dont know that it would do any better for a track day guy.

 

[fatbillybob]

We racers let the dust boots burn off or delete them. They are of no use to us.

 

[TeeLew]

At some point, the biggest shortcoming of the stock package is the ABS tuning. I wish we had a way to address that. The caliper & disc sizing is more than adequate for most people with stock GT engine power and street tires as long as pads & fluid are up to snuff. I think putting 2-piece discs and real brake ducting on the car would be a substantial gain.

 

[fatbillybob]

I think putting 2-piece discs and real brake ducting on the car would be a substantial gain.

Vorschlag proved that the PP1 undertray channel ducting and big brake deflectors works better than tube based ducting. I said great. I don't want to fab those anyway and we always destroy them when tires rub on the tubing. The Vorschlag deflector is under $150 bucks but easy to make. I needed some ASAP for a weekend race so I just made my own from aluminum stock. I would just buy Vorschlags just to save the time. I tested my creation at autoclub speedway last week in a 30min sprint race with the biggest brake zone about 130mph to about 50mph into the infield. Ambient was only about 70F and the big deflectors worked fine. Just like we racers don't use the dust boots we also don't need the protector plate that covers the inside of the rotor and spindle. I (like vorschlag) run without those and that gets more air right to the center of the rotor. I do not see much of an advantage to dust boots or the inside protector plate even on a streetcar.

 

[TeeLew]

I (like vorschlag) run without those and that gets more air right to the center of the rotor. I do not see much of an advantage to dust boots or the inside protector plate even on a streetcar.

I honestly doubt deflectors are better than a well thought out ducted arrangement, but if the deflectors are enough, then the extra work, weight & complexity is unnecessary. They work fine for Porsche Cup cars and it's going to be a rare Mustang that can get around a racetrack faster then one of those.

For me, the biggest issue is getting the vents on the correct side of the brake bell. Venting on the outside of the disc is just ridiculous.

 

[fatbillybob]

Vorschalg did all kinds of testing. I forget where you can read about it. The splitter channel ducts showed cooler brake temps. They even combined 4" hose ducts with the splitter channel ducts and that did not reduce brake temps over the channel ducts alone! That was a huge surprise. Airflow is a strange thing. Personally, I'm happy to have one less thing to fix and maintain.

 

[fatbillybob]

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