Rear brake pads for racing

[302FAM]

Any suggestions on rear brake pads for racing events (maybe more on the endurance side, hpde as well). Rear calipers are stock 2012 Boss 302 with drilled and slotted rotors. Something similar in characteristics to Pagid RSL29 (but way less costly) would be great.

 

[Mad Hatter]

Really like the Pagid rsl29 on the rears, they are expensive as hell but they can easily can last a season..... (maybe two??). Also used the Gloc r12, cheaper but last half as long. Always assuming you have traction control all the way off....

 

[Mad Hatter]

Really like the Pagid rsl29 on the rears, they are expensive as hell but they can easily can last a season..... (maybe two??). Also used the Gloc r12, cheaper but last half as long. Always assuming you have traction control all the way off....

Did you say drilled and slotted rotors ... Be careful with drilled rotors. You are going to spend $$$ changing discs all the time as the cracks go from hole to hole. They are more for Bling then track.

 

[302FAM]

Did you say drilled and slotted rotors ... Be careful with drilled rotors. You are going to spend $$$ changing discs all the time as the cracks go from hole to hole. They are more for Bling then track.

Thanks for the info, much appreciated. The overall set up was used for several years before I acquired the vehicle but yes, when I change out the rear rotors I might go with something different, so far so good.

 

[TeeLew]

In general, you're looking for something with relatively low bite and friction level, and a flat to falling temp curve. The Pagid mentioned above is that pad, but it's also not a complete unicorn. Most of the brake companies have a pad compound like this for the rear of GT and Stock Cars.

 

[Mad Hatter]

Agreed, you can even put stock pads in the rear and not suffer very much.

 

[Bill Pemberton]

Question on rear rotors, but have to wonder what you are using up front? Teelew is correct in the aspect of lower bite, effective at lower heat range , etc.

 

[302FAM]

Question on rear rotors, but have to wonder what you are using up front? Teelew is correct in the aspect of lower bite, effective at lower heat range , etc.

Thanks guys, up front is 6 piston 15" two disc Brembo pros, top of the line but with unknown front pads (not Pagids up front, probably Hawks or Glocs which I bought slightly used from Kohr/Dean Martin whose team used to be right down the road from me in Michigan, the front pads are a bit used and worn). I wonder if I can get away with stock rear pads until the next round, or some type of Hawk or Gloc?

 

[Bill Pemberton]

Since you are dealing with unknowns why even bother with even more guesswork. Many will suggest you are compromising the single most important mod for overall speed and safety. Why not get a new, full set, don't cut corners, and like TeeLew suggested get a good balance by using a lower temp pad for the rear so it comes in close to the front. Check with OP Mustang , KNS Brakes, or EBC racing pads for solid suggestions. These are all site sponsors and I will admit to being biased about doing pads all from one company as I have seen drivers pay a penalty with mismatched and unknown pads. Running a set of all season tires in the front and a set of Hoosiers in the rear is not something you would do, so why do something similar with what has to stop your track beast? Just my humble opinion but then I believe many a race is won by solid brake technology and pads are so often a major key!

 

[302FAM]

Since you are dealing with unknowns why even bother with even more guesswork. Many will suggest you are compromising the single most important mod for overall speed and safety. Why not get a new, full set, don't cut corners, and like TeeLew suggested get a good balance by using a lower temp pad for the rear so it comes in close to the front. Check with OP Mustang , KNS Brakes, or EBC racing pads for solid suggestions. These are all site sponsors and I will admit to being biased about doing pads all from one company as I have seen drivers pay a penalty with mismatched and unknown pads. Running a set of all season tires in the front and a set of Hoosiers in the rear is not something you would do, so why do something similar with what has to stop your track beast? Just my humble opinion but then I believe many a race is won by solid brake technology and pads are so often a major key!

Bill, I think you're right on and I've decided not to cut corners on this one. Kohr seems to have the Pagids in stock so I might start with them. Thanks to all who commented and have a blessed summer!!

 

[JAJ]

Bill, I think you're right on and I've decided not to cut corners on this one. Kohr seems to have the Pagids in stock so I might start with them. Thanks to all who commented and have a blessed summer!!

Good call. I've been using Pagid for about a decade now and it's a case of "you get what you paid for".

 

[Mad Hatter]

Truly a magnificent pad.

 

[2012Boss302]

Kinda on subject. My 2012 Boss has the S550 6 piston front conversion and 2013-2014 Shelby rear rotors. I use GLoc R12 front and R8 rear with Michelin PS4S, 275/305 f/r. Sometimes on track, usually when getting into ABS the rear axle will hop violently. Seems like if I stay out of ABS, threshold braking, it doesn't do it.

What could be causing this violent hop? Is brake proportioning handled by the ABS unit or just the different brake compounds?

I'm going to make the move to 200TW tires early next year in the same sizes. Would this help the violence or make it worse???

 

[67GTA]

Kinda on subject. My 2012 Boss has the S550 6 piston front conversion and 2013-2014 Shelby rear rotors. I use GLoc R12 front and R8 rear with Michelin PS4S, 275/305 f/r. Sometimes on track, usually when getting into ABS the rear axle will hop violently. Seems like if I stay out of ABS, threshold braking, it doesn't do it.

What could be causing this violent hop? Is brake proportioning handled by the ABS unit or just the different brake compounds?

I'm going to make the move to 200TW tires early next year in the same sizes. Would this help the violence or make it worse???

Which hole are your rear trailing arms set in the relocation brackets? I had the same issue and the fix was reducing anti-squat (required a change in relocation brackets from Whiteline to J&M, now CorteX). This change, along with reducing the rear pad compound. I was having issue with R16f/R12r. Dropped the rear to R10 and all was well. Now running R18/R12 and still balanced. Based on this, I think your R12/R8 combo should be good - which is why I’m curious about the anti-squat setting.

Here’s a thread about this specific issue:

Thread 'Rear axle hop during track braking'
https://trackmustangsonline.com/threads/rear-axle-hop-during-track-braking.15395/

 

[stevbd]

@2012Boss302 perhaps you will find this a helpful comparison regarding brake pads and geometry: I have an '11 GT, same GLOC 12/8 brake pads as you, 4 piston 14" front Brembos and GT500 rear conversion, MM LCA brackets set in the top hole and .5" pivot hole difference (slight downward slope on the LCA from chassis to axle), stock UCA, should be about 70 percent anti-squat according to MM worksheet, zero issue with axle hop under braking.

https://www.maximummotorsports.com/assets/install/pdf/rear_susp/Mm5RLCA-57.pdf

Other things to consider, have you tried increasing the rebound on your rear dampers and do you have any worn control arm bushings?

 

[docs302]

After I bought my Cortex JRi coilovers, I was talking with Rick who also happens to work with Kohr at the track. I was asking him about adjustments and limiting the front dive/rear lift I was experiencing at the time. He asked me what rear pads I was using. I think at the time I may have been using stock pads and he told me to ditch them and get a more aggressive pad. He said the increased bite would help keep the rear end down so I made sure to get track-worthy rear pads after that. As for compounds/brands.....that's another story.

 

[2012Boss302]

he told me to ditch them and get a more aggressive pad. He said the increased bite would help keep the rear end down

I had R12's on the rear. It was a lot worse.

Other things to consider, have you tried increasing the rebound on your rear dampers and do you have any worn control arm bushings?

I do need to check my UCA bushing. The bushing in the upper differential is less than a year old. I just replaced it with a rubber one. The LCAs are new BMR w/poly bushings set on the second/middle hole. My struts and shocks are still OE 2012 Boss set on 5.

Thanks for reading.....

 

[TeeLew]

Kinda on subject. My 2012 Boss has the S550 6 piston front conversion and 2013-2014 Shelby rear rotors. I use GLoc R12 front and R8 rear with Michelin PS4S, 275/305 f/r. Sometimes on track, usually when getting into ABS the rear axle will hop violently. Seems like if I stay out of ABS, threshold braking, it doesn't do it.

What could be causing this violent hop? Is brake proportioning handled by the ABS unit or just the different brake compounds?

I'm going to make the move to 200TW tires early next year in the same sizes. Would this help the violence or make it worse???

It sounds like you're right on the edge of brake hop normally, but as soon as the ABS intervenes, it sets it off a full axle tramp. I bet a clunky downshift will set it off as well? There are a couple things to do, but reducing the anti-squat and reducing rear bias will both help. You might find a little softer rear in general gives better grip over the ripple bumps we see in a lot of brake zones. A little better braking grip may help delay the skip-slip-grip cycle which sets off the axle tramp.

 

[Mad Hatter]

I had R12's on the rear. It was a lot worse.


I do need to check my UCA bushing. The bushing in the upper differential is less than a year old. I just replaced it with a rubber one. The LCAs are new BMR w/poly bushings set on the second/middle hole. My struts and shocks are still OE 2012 Boss set on 5.

Thanks for reading.....

Just a thought, Started out with the BMR relocation setup and we used the lowest hole, that made the car quite nimble in slow, tight tracks but traction was not great and braking was nervous.. Ended up taking out the BMR setup and replacing it with the Ford racing kit as we found that the upper BMR relocation setting still added too much LCA angle. Now we use about 2.5 degrees on the LCA and the car is much better behaved.

About the UCA, went through three different units with spherical or poly bushings and all combos in-between, and all I can say is that I like the OEM one the best. Not to mention that the spherical ones last a few races before wearing out and made all kinds of problems.

 

[TeeLew]

In the dark ages, I had Paul Brown's rear control arm kit on my Fox. It dropped the axle pickup point several inches. The thing wouldn't put power down, it'd get brake hop and the rear steer would try to spit you into a ditch at every opportunity. I had decided it was faster, though, so off we went!