Brake questions

[Splatter]

Hi was wondering if any of the racers could help me out on some brake questions for my 2012 Boss 302. I have the Ford Racing ducts, braided brake lines, ATE blue brake liquid and rear dust covers off. Back on stock PFZ pads and ordered some Castrol SRF brake fluid.

Question 1)... My shop recommends I get Iron SRF discs with Hats from WILWOOD instead of the other Hatted alternatives from BAER or DBA with alloy rotors. Because of better cooling properties.

Question 2) Would getting a bigger rear disc from the 2013 GT500 help the cooling for the rear?? I have read that the lack of air to the rear and the small stock rear disc size is leading to overheating (link below).

S197 Mustang 13.8" GT500 Rear Brake Upgrade Kit - Vorshlag LLC

I am over heating and boiling my brake fluid on one track that has a steep down hill straight away with a 90 corner at the end. Almost all the heavy cars are having the same problem (except cars like the GT-R, ZL1,,, and the dam Porsches).

 

[racebronco2]

Do you have cooling ducts? Are you boiling the fluid in the fronts or rears?

 

[wheelhopper]

You say the other heavy cars are having problems. Porsches are not heavy.

You mention that you are boiling your fluid, are you over heating the pad compound as well? If you are just over heating the fluid I would install some better fluid, not that ATE is bad I would just use a fluid with a higher boiling point. Also make sure you are bleeding the brakes before each event. I would also consider installing some fans in the brake ducts pipeline or a second set of brake ducts. I would also be using iron rotors over an alloy as well.

A larger rear rotor may help if you have increased the spring rate reduce weight transfer to the front during braking.

 

[BlackBolt9]

Do NOT waste your money on that rear brake upgrade. If it was necessary it would be on the car from the factory. I've worked on Grand Am, World Challenge, and NASA S197 mustangs and have never seen a reason for that rear brake upgrade. The only time I've seen those rear brakes used was with the 15" front brakes they were designed to work with by Ford.

For the race track run PFC01 front pads with PFC97 rear pads. That's the most common combination I've seen used by "the pros" on this car. Obviously street pads would be different. If you are still having trouble with the pad and fluid change then work on getting a little more ducting. Safety wiring a hose to the front of the rear control arm and pointing it at the caliper will help alot with the rear.

As stated above make sure you bleed brakes before every event, sometimes in between sessions during the event if the track is really rough on brakes. If you are still having trouble, I'd be curious of your driving experience. I know I was ALOT easier on brakes once I learned to brake properly.

 

[wheelhopper]

^Good point on proper brake use. I have had a lot of good students, that had were fast and had the proper line, that would tend to start braking early with light pedal effort and then at the proper point brake hard. They did this to have confidence that the brakes would work. The problem it created was the light pedal effort just a few brake markers early creates some heat. So instead of the pads being 500d. at the start of the braking zone, they may have been 800d. due to the early brake ride. So instead of the brakes being say 1000d. at the end of the brake zone they would be 1300d. This heat, of course, transfers to the calipers/fluid.

I hope this makes sense. Keep in mine the above numbers are theoretical and may likely be higher.

 

[David Hester]

^ I agree. Riding the brake pedal in happens alot. I was watching a Miata with instructor at a SCCA TT event this past weekend at Barber in B'ham.
He was on the brakes early, but not really slowing. Later sessions he was stomping brakes later. Still not a good idea, as you could see the front go down and then he would release before he got to corner, and then reapply. You want controlled but firm application and then slow release as you turn in..trail braking.
I like Wilwood stuff. I used Wilwood rotors with PBR calipers on A/Sedan car and now use complete Wilwood rotors/calipers/ and pads on the SPU car.

 

[sn95Cobrakai]

I run 13" wilwood rotors and SL6R calipers and use wilwood 600+ for fluid right now. Polimatrix pads front. Stock calipers/rotor setup with hawk blues in back. Im in at 3400 lbs im guessing. The setup seems to handle most of what I throw at it. The wilwood 600+ doesn't cook like other fluids do when trail braking. The best fluid I have used is Castrol SRF, but at over $60 a pint, I couldn't justify it over the wilwood fluid ($20). But I can tell you with the Castrol I haven't had any stories of brake fade, even at road America.

 

[MFE]

Do you by chance have big feet, or wear wide-soled running shoes when you drive? I once blew threw a set of front pads in one track day, a ridiculously, record-breaking cold day in the upper midwest. I initially thought it was something to do with the cold, and the brakes seemed strangely weak all day. Only later did I realize it was because I was wearing hiking boots trying to stay warm, and I was constantly catching the brake and gas a the same time.

 

[Splatter]

Thanks for all the pointers! Ill drop the idea of the larger rear discs and see if I can get another second set of cooling ducts for the front discs. (already have the ford boss racing ducts)

Not sure if the brakes are over heating in the front or rear (how do you tell?). But once they pedel went to the floor a couple of times.. its made me very wary of the brakes which is probably making me brake sooner and longer then I should.

I will try changing my brake points at the track tomorrow, Flushed with new ATE while I wait for my Castrol SRF to arrive.

I still need to drive to the track, so either I swap them there or get something safe for the road as well. Would any one say the Ferodo 2500 are any more track oriented then the HP+ pads??

 

[cobra-boss]

I think you are working the HP+ pads outside of there heat range. The Ferodo 2500 may be a bit better BUT they are still listed as a street pad. Here is a site that i have used to find the difference in pad compounds. Racing Brake Pads - TopBrakes.com - Your source for performance brake rotors, brake pads, brake fluids, and brake hoses

I change my pads at the track. At my last track day I forgot to change them back to the street pads before driving home (about 100 miles). Cold stopping distance was longer and they made some noise.

How big are your ducts? 2"-3"-4"?

Do your self a favor and pick up some pads at are more of a full race pad like PFC 01, Carbotech XP20, Porterfield R4, Raybestos ST-43 , Hawk DTC70. The Hawks are hard on the rotors and if the dust gets wet and left to dry, it is a almost impossible to remove. Be prepared to spend $250-$350 for a set of pads.

I have PFC 01 on my car per the recommendation of Rehagen Racing and LOVE them.

Jim

 

[darreng505]

Do NOT waste your money on that rear brake upgrade. If it was necessary it would be on the car from the factory. I've worked on Grand Am, World Challenge, and NASA S197 mustangs and have never seen a reason for that rear brake upgrade. The only time I've seen those rear brakes used was with the 15" front brakes they were d

esigned to work with by Ford.

For the race track run PFC01 front pads with PFC97 rear pads. That's the most common combination I've seen used by "the pros" on this car. Obviously street pads would be different. If you are still having trouble with the pad and fluid change then work on getting a little more ducting. Safety wiring a hose to the front of the rear control arm and pointing it at the caliper will help alot with the rear.

As stated above make sure you bleed brakes before every event, sometimes in between sessions during the event if the track is really rough on brakes. If you are still having trouble, I'd be curious of your driving experience. I know I was ALOT easier on brakes once I learned to brake properly.

Capaldi & ford racing added the 15" gt500 rear brakes to their 302's. Also Roush runs them too. I saw them at Vir for superfest.

OP, ask a real grand am team what they think. Email [email protected]. They will give you up to date advice. All the grand am mustangs run larger rear brakes now.

 

[BlackBolt9]

Capaldi & ford racing added the 15" gt500 rear brakes to their 302's. Also Roush runs them too. I saw them at Vir for superfest.

OP, ask a real grand am team what they think. Email [email protected]. They will give you up to date advice. All the grand am mustangs run larger rear brakes now.

Maybe you should get your info correct before calling someone out. I work for a Grand Am team also, we won the championship in 2009.

The GT500 rear brakes aren't 15", the fronts are. The big rear brakes are only ran with the 15" front brakes. They are also only ran with the $$$$ Bosch aftermarket ABS system also. These two things are mandated by Grand Am if you want to run the bigger brakes. So obviously Roush follows those same rules.

Of course everyone runs the bigger brakes now. The Bosch ABS system is what makes it the most worth it since you get about 0.4G more force under braking with it. Of course it's also well north of $10,000.

The big rear brakes are not necessary to have a safe, fast Mustang on a road course.

 

[darreng505]

Of course they're not necessary but that wasn't the question really. They're helpful and a worthy upgrade for the reasons I stated. I respect your past knowledge but this isn't 2009. I talk to race teams all the time and follow their advice for my own performance improvements.

I will post the link to the gt500 rears I mentioned. I saw them in person.

 

[MFE]

but not everyone is as eager to throw $10,000 at a problem that can be solved with $250 worth of brake pads.

 

[darreng505]

but not everyone is as eager to throw $10,000 at a problem that can be solved with $250 worth of brake pads.

Huh?

$479 for the bigger gt500 rear upgrades....see the first post.

Lets try to help the OP and not throw zings...

 

[MFE]

Because you need the big-bucks ABS upgrade to make it work properly and not just be blingy added weight. Follow along.

Meanwhile, some of us ARE trying to help him with things that will actually do something for his particular situation other than lighten his wallet.

 

[David Hester]

^ ah, there's the rub.

I respect your past knowledge but this isn't 2009.
I will post the link to the gt500 rears I mentioned. I saw them in person.

First off I'm just a club racer, but I've been doing it for a bunch of years. I probably did my 50th SCCA competition race back 12-13 years ago. I started time trials in 1994, and road racing about 10 years ago.
Let's look.

2011 BARBER
GS 1 Foster / Maxwell Multimatic Motorsports / Mustang Boss 302R 1:36.906 85.443

2013 BARBER
GS Atterbury, J
Blackstock, S
Roush Performance
Mustang Boss 302R GT
1:36.627

Lot of money to go 3/10ths faster in a Mustang...
Unless I was a pro making money, I'm thinking I'd spend my bucks on track time. ;-)
When I was doing my SCCA comp school years ago, my instructor raced (still does) TransAM. He followed me and would fill my mirrors on both sides. Told me later he was trying to show me how much track I was not using and therefore, not driving to the car's potential. If you aren't using ALL the asphalt and then some, you aren't driving what your car can do. He convinced me I could (and did-a few times) flatfoot down the hill at VIR into 17.
Now go back and look at the video. Are you using all the track?

 

[BlackBolt9]

Of course they're not necessary but that wasn't the question really. They're helpful and a worthy upgrade for the reasons I stated. I respect your past knowledge but this isn't 2009. I talk to race teams all the time and follow their advice for my own performance improvements.

I will post the link to the gt500 rears I mentioned. I saw them in person.

HA! Dude. Really? Guess what, the team I work for still raced in Grand Am this year. Guess what, we tried to run the 15" front brakes with the Shelby big rear brakes without the Bosch ABS at Daytona 2013. Grand Am made us go back to the 14" brakes before the race because we weren't running the Bosch system which was against the rules. In the race, Roush won with a best lap time of 1:57.171. We finished a lap down because of a pinched air line during our pit stop but on the 14" brake system and Ford Racing ABS we managed a best lap time of 1:57.631. We ran with the leaders but were a lap down because of the pit stop.

I talk with many Grand Am teams frequently, since I've worked with/against them for the last 5 years (guys at Roush/Capaldi/and many other teams that don't have Mustangs). I'm more than well aware of the current state of things in Grand Am. I'm also well aware that the big rear brakes ARE NOT NECESSARY to have a great mustang race car. Did we switch to the 15" big brakes after Daytona? Yes. Did we spend a crap load of money to get the Bosch ABS? Obviously. Was it really worth it? Depends on who you ask.

The whole reason Grand Am started to allow the big brakes and Bosch ABS was because the mustang teams were pissed the Camaros could out brake them. They used Jack Jr.'s crash at Laguna Seca the year before (which broke both of Jack's wrists) as the reason they needed them. Realistically, it was because we weren't competitive with the other cars because they were already allowed the Bosch ABS system.

BTW, don't waste your time posting the link. The link in the opening post is the correct kit if you really are looking to add them. But they are an expensive upgrade, when all that's really needed are some real track pads, and at the worst tracks, such as Mid-Ohio, some ducting to the rear brakes. Done. For alot less money.

Because you need the big-bucks ABS upgrade to make it work properly and not just be blingy added weight. Follow along.

Meanwhile, some of us ARE trying to help him with things that will actually do something for his particular situation other than lighten his wallet.

You don't need the Bosch ABS for them to work properly but they won't stop you any faster without it.

And FWIW, the Grand Am 15" brakes only use the stock Shelby rear parts, the fronts are still aftermarket.

 

[Splatter]

Well, really not going to spend north of 10 grand on the brakes!! Dropping the larger disc idea and going to Pagid RS29/RS 56 pads with Castrol SRF and the installed 3 inch ducts. Removing the rear dust shields did seem to help a little. That and more seat time will be the short term goal. I am having some trouble keeping keeping up to some freinds in a stock automatic ZL1 and a fixed up SS with coil overs and 550hp!. Hope I can gain time in braking with the new setup. Will see in a few weeks!!

 

[darreng505]

You're doing it right, but sorting out all the opinions out there will take some time.