SGwick

thx 5.monster, I've decided on dtc60 fronts but torn between hps+ or hps 5.0 for the rears. I'm concerned about noise when using it mostly for street and 4 trackdays. I want to leave the rears in for track and daily. What do you think?

SGwick

What do you think about dtc60s upfront and xp8s in rear?

redonblackpony

I run xp10/xp8 with dedicated rotors for track days. For street driving I change out only my front pads and rotors to Hawk hps, leaving the Carbotech xp8 in the rear. And they have been squeaking just a little bit as of lately during Street driving.

SGwick

Thx redonblackpony :-) ordered DTC-60 (f) & XP8 (r). Both operating temps are great just hope XP8 friction doesn't mess with brake bias (causing oversteer) oh well

5.M0NSTER

Yup, same here as redonblack. I leave the XP8s permanently. They squeak a little, but its really no big deal, and like they say: "brakes squeal because race car"

So what made you go with the DTC60s? From what I hear they are a pretty serious high grip pad. The reason I ask is because of brake bias like you mentioned. XP8s are grippier than stock, but isn't the DTC60 very grippy? Or is it a medium grip compound? I'm afraid you may experience what I did. But it wasn't oversteer, and it was controllable, just annoying.

My car would brake dance in high speed brake zones. The tail would swing left and right a few inches. I ended up putting a few degrees of steering to compensate. That's not supposed to happen though. But that was because I was running XP10 with stock rear pads for the first 2 seasons. The brake bias was too far forward, and I ended up under braking the rear. So the rear of the car would "run into" the front, and cause this wobble.

After I returned the bias to normal by properly matching the front to rear bias it went away. Give it a shot, but if you run into similar issues you know what to do.

SGwick

I bought permatex extreme brake parts lubricant to help with the squeal putting on backing plate.

I was looking at dtc-50/60 and xp10 for the fronts. Really I based most of my decision on operational range of pads (matching them) = XP10 close to DTC60 (actually DTC50 was closer in temp but friction was closer to DTC70s, weird), considered mustangs 3.6k weight, and I already have hps in front I went with DTC60.

For the rear I looked at XP8, temps, HPS, HP+, HP 5.0 but the only rear hawk pad to match XP8 was hawk street/race pad (mostly reviews for noise/dust) and that was considered mostly a dedicated race pad for track only. So with no suitable substitute I went with XP8s (easier on rotors and a softer initial bite)

5.M0NSTER

Hopefully it works out. I don't anyone running that combo, so we'll see. I'm interested to hear back what your experiences are!

SGwick

I was thinking I wanted to maintain front brake bias so I didn't have oversteer (rear brake lock) under full braking. I figured that would be easier to control verses the rear dancing. Never considered "too much front bias", would lead to front lock/slide. We'll see, man so many variables to think about :-)

Was also considering tracking with TC off but not sure. Last time with sport mode, abs was kicking in (shaking felt through steering wheel) :-)

SGwick

Running dtc60s up front and possible more front brake bias I think I'll have to stiffen front struts to slow harder brake dive

5.M0NSTER

ABS and EBD (electronic brake force distribution) are enough to prevent wheel lock. Locking was not the issue for me, but the tail wag was uncomfortable. More friction in the rear fixed it though, so if you run into issues you can either increase rear friction or reduce front.

I wouldn't worry about over steer with higher negative brake bias unless you're in a habit of trail braking

Bert

I always wondered about that with respect to bigger rotors on the rear. The rear brakes on these cars do work pretty hard and I have had more issues with the rear getting hot than the front. Some guys put the bigger GT500 rotors on the rear; wouldn't that cause the same issue?

5.M0NSTER

If you're worried about over-braking/locking the rears, main issue is actually with the compound.

When you change to a larger diameter rotor the arm of force chages, and multiplies your brake torque vs. brake pressure chart by a constant factor. That means that the gradient of brake torque change stays the same (delta tq vs, delta pressure), though the values are elevated compared to stock.

But if you switch to an aggressive pad, that changes the rate at which brake torque ramps in. So there is lot steeper gradient in how fast torque is changing compared to haw fast pressure is changing. The sudden change in gradient causes the issues with early locking/abs entry.

Hope the makes some sense!

SGwick

It potentially could but it would depend on the rest of your suspension setup. It's not like race cars you've seen where they have a brake bias dials they can adjust on the fly (due to fuel weight change, rain, suspension setup, tire condition). I say its harder for us because we're basing it on other people experience, manufacturer recommendations, and forum comments/recommendations. And because ours is fixed once set (install brake pad) purchasing the correct pad combo is vital (no room for mistakes because of limited funds) :-) So long story short: It potentially could but it would depend on the rest of your suspension setup

SGwick

Go with above Bert, it's factual verses mine, opinion :-) We can always count on you 5.Monster :-)

redonblackpony

What causes the rear brakes to overheat on the track is running with traction control on or running sport mode. The only thing that works for me is to disable traction control and stability track altogether.

5.M0NSTER

Ah, that's a good point redonblack.

I have no rear over temp issues with my setup, but I run in Advancetrack Off, or Sport mode. If you do keep sport mode TC is still on, and so is vdc. I've gotten rear pad deposits from that before. You have to be really smooth in Sport Mode to avoid excessive TC/VDC hits.

Bert

Yes I do believe that is what caused it for me in the past -- using sport mode. Lately I have been turning it off completely. Sometimes the TCS fights me, sometimes it has saved me . . . with it turned off, I'm on my own.

But I know others have had rear brake overheating issues, for example dmichaels went to both bigger rotors and a rear brake cooling set-up.

SGwick

Well I finally got my DTC60 and Carbotechs XP8, I'll find out if this combo works when I run Gateway and get it my brakes sorted before running Road America

dmichaels

Chiming in...

First you'll likely enjoy the DTC60's. Aggressive pad that brakes HARD. Hope you're running R comps cause that pad is far too much for street tires. I think it'll work fine with xp8's in the back

I discovered very late last season that one of my rear caliper banjo bolts was ever so slightly too long and was rubbing on the piston inside the caliper. This was causing it to not retract enough and thereby rub the pad and create excessive heat. It's fixed now and at my last event, I had no brake issues to speak of. That said, my rear brakes still get super hot and I'm glad I did the gt500 rotors and read cooling. The other aspect of the gt500 rear rotors I e noticed is they seem to resist surface cracking much more than the GT rear rotors. Likely cause they are staying cooler, but I see almost no wear and zero indications of cracking after probably 10 track days on them.

For pads, I've been impressed with my Raybestos setup front and rear. The pricing I found could not be beat either

SGwick

Thx dmicheals for chimming in, now I'm looking at Toyo/Nitto r compound tires :-( the list never ends...