EdwardGT

I'm upgrading my front brakes to a Stoptech 355mm setup with 2-piece rotors; and I thought I might upgrade the rears as well.

FWIW, I totally burned through my rear stock pads with 12,000 miles on them in 4 20-minute lapping sessions Saturday night - down to the backing plate on one pad. The fronts are maybe 50%. WTF? Of course, TC was disabled. How did these go so quickly. What was odd was they didn't seem to wear as much as just melt away. There is tons of pad deposit on the rear rotors. I guess I"ll have to clean that off with my race pads. I really didn't expect the stock pads to do so badly since I was running on street tires - not R-comps.

Sleeper_08

I am not surprised you burned through the stock rears so quickly.

The rear brakes seem to heat up pretty quickly under hard braking, which can get up to 1 G with high performance street tires, and you need good pads in there.

It also seems to depend on whether you are running a track that allows the brakes to cool between corners and one where you are hammering them repeatedly corner after corner with only short straights between them.

I've even considered trying to add rear brake cooling but that is starting to get pretty hard core for a DD

Philostang

Sorry, no experience with Performance Friction pads, but I'll second Sleeper's comment on the rear pads (he's more hardcore than he lets on...c'mon, do it and then write it up!). The S197 Mustangs are finally using their rear brakes. I've seen this on my car and others as well, so hey at least you're not alone!

If someone has an actual technical explanation of why the new platform is more aggressive on the rear brakes, I'd love to hear it. For now, I just stock a spare set of pads and rotors in the tool box and keep running.

Best,
-j

Sleeper_08

Now that I'm getting up enough nerve to hit 130+ MPH on the back straight I'm fnding that when hauling it down hard, +- .75 G,from that speed that the rear end likes to hop sideways. I suspect this is becaause the rear is getting light due to aero lift at these speeds. Any thoughts?

RodeoFlyer

Were you getting into the ABS?

Sleeper_08

I was not getting into the ABS. I find at Mosport that the corners are so fast, most entry speeds are around 80 MPH, I don't get into the ABS. This may be me just being too cautious.

EdwardGT

I haven't really haven't felt the rear end getting squirrely. This past weekend I was braking from 125+ plus at two areas on the track. However, at those speeds, straight-line braking is a must if applying full braking pressure.

SlideWRX

The closer we get to 50/50 weight distribution, the more braking can be sent to the rear. Porsche's are infamous for the braking they can do because of their rearward weight balance. On braking, weight transfers forward so the rear brakes on a mustang likely still only handle ~30-35% of the braking. A Porsche is likely near 40-45% rear braking bias. I'd like to hear from someone who has test results.

Also, the ABS and traction control are getting better calibrated to brake at peak performance versus previous mustangs. I know a guy that has worked on mustang stability control and they do a LOT of development work to get the best out of the system. The Mustang has Electronic brake force distribution, which means it can change the bias front to rear for peak performance even without the abs kicking in.

Philostang

Thanks SlideWRX! I had heard that Ford spend quite a bit of time in developing their traction control, but they seem to have done much more behind the scenes.

I hadn't thought of the static weight distribution contributing to this (could this mean I hadn't really thought much at all ? ). Do you think this means that those of us with stiffer springs and less nose dive are likely to push the rear brakes even harder? I'm thinking that the electronic brake force distribution is not a static system, but tied into some array of sensors. If so, then the better we do on the suspension side the system should be utilizing the rears even more. Just a thought.

Best,
-j

EdwardGT

Here's my opinion. I don't think that these cars have any sort of weird rear brake bias. Instead, I think that the rear pad compound is just much "softer." The reason I say this is because my track setup had been Hawk HT10's on the front and HP+'s on the rear. I only use these pads on the track. However, I wore down the front pads much more quickly than the rears. Yet one trip to the track wears the stock rears to the backing plates while the fronts have about half the pad left. This leads me to believe that the stock rear pad compound is the culprit.

Also, the I was inquiring if anyone had used this setup, not PFC pads.
http://www.hrpworld.com/index.cfm?tp...action=product