Anyone tracked stock rotors with XT970 or other track pads?

[destructure00]

...if so, what was your experience? I have done stock rotors with stock pads (not good), and aftermarket rotors with aftermarket street and track pads. Haven't heard much about XT970 or similar track pads with stock PUP rotors. Wondering about any fade, pad transfer, rotor wear, etc.

 

[kbecks13]

I've used the UP competition pads (the more aggressive compound they have) with stock rotors and they've been pretty good for me, though i've heard from others (@mcbarnet007) that they are relatively abrasive with lots of use - but he definitely tracks more than i do.

Need to swap pads soon and will try to get some rotor measurements to quantify the material loss.

 

[beastmode13]

I've used the UP competition pads (the more aggressive compound they have) with stock rotors and they've been pretty good for me, though i've heard from others (@mcbarnet007) that they are relatively abrasive with lots of use - but he definitely tracks more than i do.

Need to swap pads soon and will try to get some rotor measurements to quantify the material loss.

You beat me to it. @mcbarnet007 is on the complete stock brake with upgrades in fluids and pads. Not even sure if he upgraded to SS lines. However, IMHO two factors contribute to the stock caliper/rotors working for him. 1. He doesn't track the full 15/20min session. He is out there for fast lap time with optimal SOC. Once SOC dips below a threshold, he is done for the session. 2. He is fast. Fast driver is fast because they carry more speed through turns. Which typically means he uses less brakes than us slow driver.

 

[mcbarnet007]

I've used the UP competition pads (the more aggressive compound they have) with stock rotors and they've been pretty good for me, though i've heard from others (@mcbarnet007) that they are relatively abrasive with lots of use - but he definitely tracks more than i do.

Need to swap pads soon and will try to get some rotor measurements to quantify the material loss.

I've tried the UP pads and they put deep grooves on my stock rotors which required a replacement. I think the UP pads maybe OK with upgraded rotors that has better cooling but it doesn't really work on stock rotors. I tracked XT910 on stock rotors as well and while they don't abuse the rotors, they do overheat after 1 fast lap. I think XT970 will do much better.

 

[destructure00]

I've tried the UP pads and they put deep grooves on my stock rotors which required a replacement. I think the UP pads maybe OK with upgraded rotors that has better cooling but it doesn't really work on stock rotors. I tracked XT910 on stock rotors as well and while they don't abuse the rotors, they do overheat after 1 fast lap. I think XT970 will do much better.

Yeah 910 are no good for tracking. Are UP pads more aggressive than 970? I can try the 970s on stock rotors, just trying to get an idea ahead of time if I'm signing myself up for a crappy track day lol.

 

[mcbarnet007]

You beat me to it. @mcbarnet007 is on the complete stock brake with upgrades in fluids and pads. Not even sure if he upgraded to SS lines. However, IMHO two factors contribute to the stock caliper/rotors working for him. 1. He doesn't track the full 15/20min session. He is out there for fast lap time with optimal SOC. Once SOC dips below a threshold, he is done for the session. 2. He is fast. Fast driver is fast because they carry more speed through turns. Which typically means he uses less brakes than us slow driver.

I typically run 1 out lap, 2 fast laps, and one cool down lap when I am chasing personal bests so you're right I don't need the best cooling on brakes. Although fast drivers carry a little more speed through the turns, they also end up at a higher speed at the end of the straight which mean you have to brake pretty hard as well. The stock caliper even though is not forged, it is a one piece with really beefy bridges which gives you very little flex under heavy braking. Unfortunately the rotor thickness is undersized and does not have vanes for optimal cooling. However, they are relatively light and very cheap to replace.

I did get SS lines =)

 

[mcbarnet007]

Yeah 910 are no good for tracking. Are UP pads more aggressive than 970? I can try the 970s on stock rotors, just trying to get an idea ahead of time if I'm signing myself up for a crappy track day ahead of time lol.

I am not sure if UP pads are more aggressive or not. They do have good bite when in optimal temp range. I have only driven 970 for a lap and they seems to stop OK but the brake force isn't linear. Beastmode13 have more experiences with them and has a good review for anyone needing more insights.

 

[MasterC17]

Does anyone know what company is manufacturing the pads for UP? The price is steep.

I believe Carbotech/Martian Wheels have the most compound options for a reasonable price at this point. The XT970 on the rear has worked well for me but I have not tried them on the front.

 

[destructure00]

I already have the 970s, so that's why I'm asking about pairing them with stock rotors. Totally open to trying something else when the time comes.

Basically I've got my eye on the upcoming MPP BBK at some point, wondering if I could or should sell my RB rotors, if I can get by with stock rotors and track pads for a bit I'd consider it. I guess I'll just have to give it a shot, whenever tracks open back up. Probably fall at the earliest at this point, it's too hot here now.

I guess one other consideration is whether or not I drive hard enough to even need anything other than stock rotors and track pads. After destroying my stock pads I went all in with pads and rotors, so hard to say what just upgrading to good pads would have done.

 

[MasterC17]

I already have the 970s, so that's why I'm asking about pairing them with stock rotors. Totally open to trying something else when the time comes.

Basically I've got my eye on the upcoming MPP BBK at some point, wondering if I could or should sell my RB rotors, if I can get by with stock rotors and track pads for a bit I'd consider it. I guess I'll just have to give it a shot, whenever tracks open back up. Probably fall at the earliest at this point, it's too hot here now.

I guess one other consideration is whether or not I drive hard enough to even need anything other than stock rotors and track pads. After destroying my stock pads I went all in with pads and rotors, so hard to say what just upgrading to good pads would have done.

I would run the XT970's with stock rotors and see how they perform. It will be worth it to spend a little extra and get the MPP BBK as opposed to using the stock calipers with RB rotors. The issue with the stock rotor sizing is that the thickness just isn't there. Even with true two-piece rotors and improved vanes the lack of thickness is the weak point. I don't think the RB rotors are going to offer much more thermal capacity. Fortunately, the in-car brake overheat warning is actually pretty reliable, so you will know if you exceed the limit.

 

[beastmode13]

I would run the XT970's with stock rotors and see how they perform. It will be worth it to spend a little extra and get the MPP BBK as opposed to using the stock calipers with RB rotors. The issue with the stock rotor sizing is that the thickness just isn't there. Even with true two-piece rotors and improved vanes the lack of thickness is the weak point. I don't think the RB rotors are going to offer much more thermal capacity. Fortunately, the in-car brake overheat warning is actually pretty reliable, so you will know if you exceed the limit.

Funny thing about that in-car brake overheating warning. I don’t recall triggering it at all during any of the seven track days I done. All with the RB 380x32mm front BBK.

I am still on RB rear rotors. With the rear, I didn’t have much problem with it. I do prefer the front, rear match, however that will require a custom job. I don’t see an AP Racing rotor ring with matching rear Tesla M3 or MS dimensions.

 

[MasterC17]

Funny thing about that in-car brake overheating warning. I don’t recall triggering it at all during any of the seven track days I done. All with the RB 380x32mm front BBK.

I am still on RB rear rotors. With the rear, I didn’t have much problem with it. I do prefer the front, rear match, however that will require a custom job. I don’t see an AP Racing rotor ring with matching rear Tesla M3 or MS dimensions.

With that setup I would not expect you would trigger it. I only triggered it once and it coincided with brake fade on stock M3 calipers. If you haven't had brake fade, you should not get the warning. I ran several track days with MS front rotors and calipers without any issue.

I currently have the AP Kit front, MPP rotors in the rear. The rear worked even with stock pads and rotors. They went quick though (maybe last 2 events if you're lucky). The XT970's have been on there for 3 events now and still have decent life left.

 

[destructure00]

I do prefer the front, rear match, however that will require a custom job.

This is why I like the MPP. Looks like the front BBK rotor will visually match their stock replacement rears.

 

[destructure00]

I don't think the RB rotors are going to offer much more thermal capacity. Fortunately, the in-car brake overheat warning is actually pretty reliable, so you will know if you exceed the limit.

I've triggered the warning with stock pads and rotors, and with XT910 pads on RB rotors. Never got it with XT970 on RB rotors.

 

[MasterC17]

I've triggered the warning with stock pads and rotors, and with XT910 pads on RB rotors. Never got it with XT970 on RB rotors.

Good to know. What was your biggest speed differential? I got it with MPP Rotors & Carbotech Pads going from 140-50mph starting my third lap on VIR Grand.

You can see it here at 3:33 when the front brake temp exceeds 1200f:

 

[destructure00]

Good to know. What was your biggest speed differential? I got it with MPP Rotors & Carbotech Pads going from 140-50mph starting my third lap on VIR Grand.

You can see it here at 3:33 when the front brake temp exceeds 1200f:

The tracks I run on are quite a bit smaller....a fast straight here is maybe 105-110 tops, so the speed differentials are quite a bit lower than what you'd see. I'd say my largest on stock setup was probably 100-40, and on the XT910 with RB rotors was probably 90-30? Those are just guesses though, I don't have any actual data to back it up.

What I did notice though is that my brake temp warning was correlated with brake pads glazing over.

 

[beastmode13]

This is why I like the MPP. Looks like the front BBK rotor will visually match their stock replacement rears.

@MountainPass any pricing and release date info for MPP/StopTech BBK?

 

[MasterC17]

The tracks I run on are quite a bit smaller....a fast straight here is maybe 105-110 tops, so the speed differentials are quite a bit lower than what you'd see. I'd say my largest on stock setup was probably 100-40, and on the XT910 with RB rotors was probably 90-30? Those are just guesses though, I don't have any actual data to back it up.

What I did notice though is that my brake temp warning was correlated with brake pads glazing over.

Good data to have on-hand though. People may want to consider local tracks and braking speed differentials before investing in a BBK. I think the Model 3 would be fine with stock calipers and supporting mods as long as speed differential isn't higher than ~75mph. Beyond that, a BBK may ultimately be cheaper in the long run. Unfortunately, there are a lot of factors to contend with, so it's hard to say for certain.

 

[mcbarnet007]

MPP told me there isn't a temp sensor for the brakes. I think it's just clever modeling of brake pressure, amount of time under braking and speed differential under braking. So any brake pads with higher bite will probably trigger the brake temp warning less. Of course they modeled the whole system for the stock config so any aftermarket parta will likely throw the equation off.

 

[AltLogic]

The tracks I run on are quite a bit smaller....a fast straight here is maybe 105-110 tops, so the speed differentials are quite a bit lower than what you'd see. I'd say my largest on stock setup was probably 100-40, and on the XT910 with RB rotors was probably 90-30? Those are just guesses though, I don't have any actual data to back it up.

What I did notice though is that my brake temp warning was correlated with brake pads glazing over.

In my experience speed doesn’t make a difference in overheating brakes. The problem is where the braking zones are located. I have a car that has run at Autoclub speedway, Buttonwillow, Willowsprings, streets of willow and all of the Arizona tracks except bondurant. I can run on all of those tracks except one without modification. At WHP East I have to remove my turn signals to allow more air to get to the brakes. That track has three good braking zones back to back to back after short straights. This is much worse than Autoclub with high speeds and only two braking zones that are back to back. (I don’t count a short tap of the brake as a braking zone)
My previous car ran yellostuff brakes and stock everything including brake fluid at Mid-Ohio, Miller Motorsports park, all the AZ tracks except AMP and bondurant. I had to upgrade the fluid for WHP East.