MarkDFW

I have several HPDE under my belt and I'm now as addicted as everyone reading this post. I estimate I will HPDE my daily driver about 6 or so times a year. I've experienced enough brake fade that I'm ready for a BBK. For budget purposes, I'm going to start with 4 piston calipers on front only and leave the stock calipers on the rear. I'm told these generally stop as good as 6 piston calipers which are only needed for serious racing or car shows. I know I can get 6 piston front calipers later and then move the 4 piston calipers to the rear. I've narrowed down my choices to the following:

1 - Used 4 piston brembo being offered by a local shop
2 - AP Racing T1
3 - StopTech ST-40

I will most likely use either Carbotech or Cobalt pads with this setup. I'm leaning towards ST-40 as it seems StopTech is pretty popular with Corvette owners. Any thoughts on which way you would go based on long run costs and what I provided?

Oh... I have a 2012 GS A6.

Rob Willis

very happy with my Hardbar/AP Racing T1 setup on my 2011 GS. I use oem rear Z06/GS calipers. Carbotech pads all the way around (one piece, not padlets in rear). Wear rates on rotors and pads seem great so far.

MarkDFW

How much are carbotech pads for this setup and which carbotechs are you running?

crease-guard

I have 4 piston Brembos on my track car with 355 rotors. I'm using PFC 01 compound in the front and PFC 97 in the back. I get no brake fade at all. Pedal and stopping ability are consistant from start to finish. My biggest issue is learning how to brake properly and to quit thinking I have F1 brakes on the car and can take it deep-deep-deep into the corner.

I spent a pretty penny over the spring having all 4 calipers rebuilt and new front race rotors, but it's worth it to have the stopping ability on the track.

Jay

fatbillybob

Mark,

I'm racing T1 with ST front and rear. ST designed the T1 kit on my car. They work on the stock master and you can just run the front and keep rear stock with no problem. They might have other kits available using the aero 2 piece rotor but the T1 kit uses real floating rotors called the trophy rotor which is a real race rotor. Brakes are awesome and very difficult to wear out rotors. I'm still on 1st rotor,
3rd set of pads, almost 2 years of racing. Great stopping power wear like stone.

As another datapoint OEM rotors I cracked on the 3rd trackday and killed carbotech xp12 pads in 1 weekend, spread out the calipers and replace in 1 year.

Buttermore is a front running T1 racer seeded to win the runoffs and he is running the full ST T1 kit. A lot of T1 racers use the AP's but there is no rear caliper kit for them. One advantage is the ability to run 17" or 18" wheels

dvandentop

hardbar ap t1 kit with the j hook rotors, unbelievable longevity

JDIllon

Since you are running HPDE's, I would suggest you go to 6 piston to start with. You don't save that much on the price and if you are thinking of doing it later anyway?? Most of us that are running HPDE's have gone to 6 piston when going to BBK. And the Stoptech is a great choice, and you can do just the fronts and leave the rears stock. I may be wrong but but I think the T1 guys are going to 4 piston because of the rules?? I think they would go 6 piston if they could. Doesn't the grand sport already have the Z06 brakes?? if so those brakes, with the newer style one piece pads by Carbotech or Cobalt do very well for HPDE's. I personally don't think going to 4 pistons on the front is an upgrade. I would go to the Stoptech ST60s with there 2 pc slotted rotors on the front and leave the rears stock for now. and when you are ready, if needed you could go to Stoptech ST40s on the rear later. The nice thing about the Stoptech setup is the front and rears rotors are the same 14" rotors. The other thing you may want to consider it upgrading to 2pc slotted rotors front and rear and staying with the stock calipers and just upgrading the pads to the newer one piece design. Just my .02 JD
Note: the operating cost of the Brembo's are much more than the Stoptech's.

r.hillenbrand

I would also look at the willwood SL6 for the front. You can get the comeplete set-up for about or under 2K and the last time I checked the StopTech's were more than that for a 6piston set-up.

MarkDFW

Stoptech says there is no measurable difference in stopping power beteen the st40 and st60. The main advantage to the 6 piston seems to be longevity from larger pads if you are racing, and not stopping power. I'm thinking starting with st40 would keep pad cost down a bit for now.

The grand sport does have the z06 brakes, but I can tell you from experience if you are on a track that is hard on the brakes, you are going to experience noticeable fade. I'm told by several HPDE instructors that the GS/z06 setup is good for a while but once it gets really hot, they can't dissipate heat very well.

The other thing working against AP is they don't have rear calipers yet for my car from what I can tell. If/when I'm ready to upgrade, I don't have anywhere to go with them because I only see front calipers on their site.

JDIllon

Are you running the one piece pads on your GS? I instruct for several clubs here in Fl. and there are quite a few guys that are running the stock calipers with 2 pc rotors front and rear for HPDE's and are having pretty good luck with that setup with the one piece pads!!!. Also the 4 piston may have as much stopping power, but due to the size of the pads, they will not dissipate the heat as well as the larger 6 piston pads and in turn not last as long. And in this case you may end up spending more on pads in the long run. I have been running a C6-Z06 for 6 year now and have use several BBK combinations, along with many students and friends that are running them also. As you have mentioned, there are many combinations that will work fine, however I think that most of us prefer 6 piston fronts over 4 piston. And we are just trying to help you from making some of the same mistakes that we made. I personally don't think that the 4 piston with the smaller pads are going to be that big of an improvement over what you have. If you read many of the past threads on brakes, many have found that going to the 2 piece slotted rotors and upgrading pads have helped improve the braking and the fade problems. That's just my opinion. I have run Brembo's fronts 6 piston and stock rears and Stoptech fronts 6 piston and stock rears, along with several others over the years. I am currently running Stoptech's all around, St60s front and ST40s rear. I have been running them this way for almost 3 years, if you look at the cost of pads and replacement rotor disc's the Stoptechs are not quite half the cost of the Brembo's. I am not saying that is the best setup!!! There are many BBK's that work great, just besure to check the pad, rotor disc, and the hdwe to mount the rotor disc COST!! Some manufactures charge extra for that hardware. JD

Adam@Amp'dAutosport.com

Mark, do you have cooling ducts? What fluid are you using?

MarkDFW

I was running the Carbotech xp10/xp8 setup but that isn't going to work anymore. I plan on running the xp12/xp10 setup and yes, I use the 1 piece pads.

I'm leaning away from Brembo because the pads and rotors cost more than if I go with StopTech or AP, and I'm not racing the car so I won't miss the performance difference much. I'm already spending more on our mutual addiction than planned and have to keep cost under control!

How does the Brembo 6 piston front and stock rear setup you ran compared with the StopTech ST60/ST40 combo you're running now? I think the ST60/ST40 setup is what I'm eventually going to shoot for.

MarkDFW

Hey Adam,

I actually PM'd you earlier and you gave me prices for StopTech and AP.

I run Motul 600 which seems to be very solid and bleed the brakes before events.

I don't have cooling ducts yet but plan on getting them with my BBK as it is a very inexpensive mod that everyone says is well worth the money.

KNSBrakes

Carbotech has VERY friendly pricing for the ST-60 calipers as compared to most other race pads.

Anthony Stark

I have a set of Wilwood SL6 LG Edition Calipers/Lines and Pads FOR SALE if your interested.

These Calipers allow you to use Stock Rotors and provide fantastic stopping power.

I am no longer participating in HPDEs and that is the reason these have come off of the car.
I also have a set of Wilwood Sl4R Calipers/Rotors, but I see your only looking to upgrade the fronts.

Adam@Amp'dAutosport.com

Mark, I would get the cooling first. And upgrade to SRF fluid and we can talk about some compound variations and see how that works for you. I see no reason to spend money on a 4 piston BBK at this point. Give me a call 2167808825.

JDIllon

As I mentioned, the cost of running the Brembo's is almost twice that of the Stoptech's. As far as stopping, I think they were about equal. I have had great performance out of Cobalt XR1s and they last a long time. I have run other pads but the Cobalt's seem to be working the best of me. I have been very happy with the Stoptech's. JD

MarkDFW

Good info. Thanks!

RedLS1GTO

PM sent...

UstaB-GS549

Both the AP T1 and LG/Wilwood calipers use the same 20 mm thick pads (Wilwood 7420 profile). They are the least expensive pads you can buy and they are substantailly thicker than stock.

I decided on the AP T1 basic kit and use it with stock NAPA type rotors. Pad taper is nil and they seem to last forever. I do not have ducts and run either Prestone or Valvoline synthetic brake fluid (cheap and 500F dry BP). I bled brakes once this season... maybe twice.