Rear brake wear

[steveespo]

I posted this in the parts for sale section in response to Ken from KNS Brakes inquiry on how my XP 20 rear pads performed.
Would like to hear and see others rear brake performance issues and likes/dislikes for pad selection.

Quote from: KNS Brakes on June 24, 2014, 10:43:30 AM
What is your view on the XP-20 back there?

It's not common to have the high rear pad wear at least we have not gotten that feedback before. As noted - we also suggested that high friction rear pads may not heat up enough for some users.

It is a small pad back there. Seems like there should be some caliper upgrade to get more surface area back there.

-Ken

Ken
Here are the results from 3 1/2 hours on track with the XP-20s at Summit Point;
http://i1108.photobucket.com/albums/h416/steveespo/photo42_zpsf177ea0d.jpg
http://i1108.photobucket.com/albums/h416/steveespo/photo38_zps91895252.jpg

As you can see the pads wear unevenly and this has been consistent no matter which compound I've used. The outer pad wears much faster than the inner (piston side). I swapped them out to in to get the most life out of them.
Also cracked the right rear rotor so some cooling solution needs to be found which will hopefully help all areas for durability.
http://i1108.photobucket.com/albums/h416/steveespo/photo112_zps87febabe.jpg
Performance is excellent, I love the feel of the Carbos and the XP 24/20 set is my favorite.
Steve

 

[Black Boss]

I have also been experiencing fast wear on rear brakes, especially with the 302S ABS module in.

Have returned to stock ABS to get a baseline:

Front pads (Pagid RST2) lasted 3 days (5 hours of track time)
Rear pads (Pagid) lasted 8 days (12.5 hours of track time)

Wear on rear left outer pad is the highest (1.5mm higher than inner)

Rears only lasted 4 days or 7 hours with 302S module.....

Have a set of XP24/10's that I will install after I burn through my last set of Pagids.......

 

[steveespo]

OK so I'm not alone or crazy. I do know that I have checked and all components are working properly. It's not the end of the world, will be looking to add cooling hoses to get air to the caliper/rotor and axle bearing area.
Steve

 

[Black Boss]

OK so I'm not alone or crazy. I do know that I have checked and all components are working properly. It's not the end of the world, will be looking to add cooling hoses to get air to the caliper/rotor and axle bearing area.
Steve

Yea, but those rear pads are a real pain to change .

Also burnt through the rear caliper dust shields with the 302S ABS and you can't buy them without buying the replacement calipers.....

 

[ford20]

OK so I'm not alone or crazy. I do know that I have checked and all components are working properly. It's not the end of the world, will be looking to add cooling hoses to get air to the caliper/rotor and axle bearing area.
Steve

How would you do that?

Yea, but those rear pads are a real pain to change .

Also burnt through the rear caliper dust shields with the 302S ABS and you can't buy them without buying the replacement calipers.....

Haha you can say that again. I would almost rather just buy new calipers than change the pads

 

[cloud9]

I know you guys aren't Hawk fans, but I run the DTC60s in the back. I have 5 track days on new pads this year and I'm not 50% through them yet. I'm on the second season on my rear rotors and you guys know I'm not exactly easy on the car. I don't feel like the rear end is "loose" under heavy braking at all. I am on the stock ABS module though and everything I've heard is that the rear engages much more with the 302R module. I've heard second hand that some of the racers feel there's maybe too much rear bias with it, but I haven't used it so cannot express an opinion personally. I'm not sure how the DTC60s would play with your front Carbotechs but I have been very happy with them.

For comparison I do go through front pads in 2-3 days on technical tracks and one and a half days at Road America! Also I get from 3-6 track days on front rotors.

 

[steveespo]

Might talk to Pete about Pagid rears. I am not afraid of mixing components if they work. Plus I can do a rear pad swap in 20 minutes so if it's bad then I could switch back. Wish there was an easy 4 piston rear caliper solution. The best way would be a Ford 9 inch conversion, not anywhere the axle end play of the 8.8 but then the driveshaft, caliper brackets, brake lines and hoses, diff cooler would all have to be custom fabricated. Big $$$$$ for minimal performance gain. Cheaper to just keep buying consumables.
Steve

 

[cloud9]

I know you guys aren't Hawk fans, but I run the DTC60s in the back. I have 5 track days on new pads this year and I'm not 50% through them yet. I'm on the second season on my rear rotors and you guys know I'm not exactly easy on the car. I don't feel like the rear end is "loose" under heavy braking at all. I am on the stock ABS module though and everything I've heard is that the rear engages much more with the 302R module. I've heard second hand that some of the racers feel there's maybe too much rear bias with it, but I haven't used it so cannot express an opinion personally. I'm not sure how the DTC60s would play with your front Carbotechs but I have been very happy with them.

For comparison I do go through front pads in 2-3 days on technical tracks and one and a half days at Road America! Also I get from 3-6 track days on front rotors.

Correction 7 days on these rear pads this year..... Yea not saying you can't mix brands just that Hawk 60 rears and 70 fronts are a proven match on a Mustang. There's almost certainly a Pagid rear compound that would work with your Carbotech fronts.

 

[2012-Boss]

Yea, but those rear pads are a real pain to change .

Also burnt through the rear caliper dust shields with the 302S ABS and you can't buy them without buying the replacement calipers.....

If you are referring to the rubber dust boot that goes over the rear piston, you can buy them from Rock Auto. The boot is part of a caliper rebuild kit from Centric that costs $3.77.

To replace the boot, remove the caliper, action the parking brake lever until the piston comes loose, remove old boot, install new boot, screw the piston into the caliper, remount caliper and bleed the brakes.

 

[Black Boss]

If you are referring to the rubber dust boot that goes over the rear piston, you can buy them from Rock Auto. The boot is part of a caliper rebuild kit from Centric that costs $3.77.

To replace the boot, remove the caliper, action the parking brake lever until the piston comes loose, remove old boot, install new boot, screw the piston into the caliper, remount caliper and bleed the brakes.

Thanks ordered 4 sets!

For comparison I do go through front pads in 2-3 days on technical tracks and one and a half days at Road America! Also I get from 3-6 track days on front rotors.

Gary, you might want to check out Girodisc front rotors. I'm seeing similar pad wear rates, but am getting 18+ days out of the front rotors and replacing for heat checking rather than wear. This was on a combo of the less and more aggressive Pagids.

 

[Black Boss]

Here are the results from 3 1/2 hours on track with the XP-20s at Summit Point;
http://i1108.photobucket.com/albums/h416/steveespo/photo42_zpsf177ea0d.jpg
http://i1108.photobucket.com/albums/h416/steveespo/photo38_zps91895252.jpg

As you can see the pads wear unevenly and this has been consistent no matter which compound I've used. The outer pad wears much faster than the inner (piston side). I swapped them out to in to get the most life out of them.

Steve

Here are my Left rear pads after 12.5 hours of track time. Wear is extremely un-even, but Right rear pads are even.



Have replaced guide pins and springs to see if there's any improvement.

 

[wwilde001]

Mine looks the same with the 302S ABS and Pagid pads. When I first started learning the car, the wear wasn't as great, but as soon as I started pushing it, I am getting about 4 to 5 days out of the left rear set. Same uneven wear. Must be a characteristic of this caliper setup. Has anyone tried the PFC pads on their car? I think once I am done with the Pagid's I have, I'll try a set of PFC's.

 

[steveespo]

End play in the axles also is a factor. We turn mostly right so the left wheel is pushing the hub and rotor in against the inner pad. More wear on the inside left rear pad for me always. We are just pushing harder than most so wear is accelerated. I flip pads in to out to maximize life now. I have also made sets out of the less worn ones. Stuff is to expensive to throw away.
Steve

 

[dmichaels]

I'm also experiencing fairly high rear pad wear. I'm going through rear pads more quickly than fronts. The rears seem to heat up much more quickly than the fronts too when driving around town, so I'm getting lots of rear pad engagement under light braking levels.

The brakes are stopping really well (for the first couple laps at least) at track days. Then I get a little bit of soft pedal, but I am switching to SRF soon to support my next outing at Watkins Glen.

I am also getting uneven pad wear, although mine seems to be the piston side pad that is wearing more quickly.

I got a lot of rotor wear over the past year too, primarily on the inside (consistant with inside pad wearing more). I will note I have been running the Pagid RS56's on the street too since I don't put many miles on the car on the street. Just replaced the rotors, although unfortunately I ran the brand new pads last week at Thompson and wore them a bit oddly due to the worn rotors I had to run there (didn't have new ones arrrive yet...)

I've also been thinking about rear brake cooling. Thinking a NACA duct setup with some sort of backing plate. I need to draw something up and see if I can get a friend with a 3D printer to make me a scoop that I can test fit. Maybe this weekend....

If I do end up coming up with something, are there some others who are interested?

 

[drano38]

I guess I'm lucky because my rear pads are lasting a long time.
I put XP8 on the back when I got the Boss, have done about 13 track weekends total, and they're not even 1/2 gone. They are also wearing fairly even.
I leave them on for street use, and have about 13,000 miles total. I drive pretty mellow on the street, so minimal wear there.
When I come off track, my rear rotors are a little cooler than the fronts.

 

[Roadhouse]

I get tons of mileage out of my CT XP10s in the rear. I'm also on the stock ABS module.

 

[Black Boss]

I get tons of mileage out of my CT XP10s in the rear. I'm also on the stock ABS module.

Once I burn through this last set of Pagids, I'm going to try the XP10's on the rear.

 

[cloud9]

Here are my Left rear pads after 12.5 hours of track time. Wear is extremely un-even, but Right rear pads are even.



Have replaced guide pins and springs to see if there's any improvement.

Nothing like getting every last lick of pad life out of those Nick! ;D

 

[KNS Brakes]

Espo asked me about trying a set of the Carbotech RP2 pads on the back.

Technically the RP2 is a endurance pad, made specially for smaller, lighter, less powerful cars. But since this is going on the rear of the car I think it would be a good experiment to test out.

The RP2 is equivalent in bite to that of an XP10, so we still run the risk of overheating it and melting it because you people drive so freaking fast

If anyone is interested in giving it a shot, I don't mind doing some "experimental" pricing for the rear in RP2.

-Nick

 

[wwilde001]

I picked up a set of the Performance Friction pads with the 12 Endurance Compound. We'll see what they do on Labor Day.