Racing Brake XT910 vs XT970

[beastmode13]

FWIW. I did order a set of Endless EX90 to try. If it shows up in time, I’ll run it at Laguna in December. For 2020 season, I plan to try some CarboTech pads, had good experience with them in my MiniCooper S. CT and RB pads are more reasonable priced compare to Endless. I am close to giving up on the idea of the unicorn pad that works for street and track. Endless is my last try at this unicorn pad. If it doesn’t work out. I will go with RB XT910 for street then a CarboTech for track.

 

[Lunares]

FWIW. I did order a set of Endless EX90 to try. If it shows up in time, I’ll run it at Laguna in December. For 2020 season, I plan to try some CarboTech pads, had good experience with them in my MiniCooper S. CT and RB pads are more reasonable priced compare to Endless. I am close to giving up on the idea of the unicorn pad that works for street and track. Endless is my last try at this unicorn pad. If it doesn’t work out. I will go with RB XT910 for street then a CarboTech for track.

I've been running the XT910 for autox and that's definitely better. I should probably check them for glaze at some point.

 

[destructure00]

970 is doing fine after two days at BRP and one day at LS. In between I drove it on street for two months, which caused more wear on the pads than the 3 track days combine. XT970 provides huge amount of bite and progressively increases as the pad heats up into a braking zone. Its not as linear as I expected and experienced from other pads. So I end up over braking at end of long straights. With XT970 you can go a lot deeper into the braking zone before braking. The pad also has a soft feel at the pedal, but the stopping force is there. I attribute the soft pedal to slight brake fluid boil from the rear calipers, a bit disappointed at 3 month old Motul 660. I had rear caliper boil at end of the track days I had so far in M3. I think it’s just the way I use or over use the brakes. I will switch to Castro before Laguna in December. If I still get fluid boil issue with Castro, I will consider to upgrade the rear to one of the RB rear BBK.

@mcbarnet007 drove a few BRP laps in my car. Perhaps he can chime in on a comparison of XT970 with Endless EX90 pad on his car. Not quite Apple to Apple, as my pedal was already soft from fluid boil, and my car was around 60-50% SOC.

Very informative, thank you. I think I'll pick up a set of 970s and pair them with the RB rotors for the track, and use the 910s with the stock rotors for street. There's still plenty of pad left on the 910s, even after I just sanded off the glaze. I missed my 2nd session working on these, hopefully they will hold up so I can finish 3rd and 4th sessions today.

Thanks for your thorough explanations about your experiences.

 

[destructure00]

I've been running the XT910 for autox and that's definitely better. I should probably check them for glaze at some point.

FWIW the 910s did great for the first 2 of 3 sessions my last time out. 3rd session was dicey. I should have checked the pads for glaze prior to today's session, but I figured it was brake fluid boiling or something else.

 

[destructure00]

FWIW. I did order a set of Endless EX90 to try. If it shows up in time, I’ll run it at Laguna in December. For 2020 season, I plan to try some CarboTech pads, had good experience with them in my MiniCooper S. CT and RB pads are more reasonable priced compare to Endless. I am close to giving up on the idea of the unicorn pad that works for street and track. Endless is my last try at this unicorn pad. If it doesn’t work out. I will go with RB XT910 for street then a CarboTech for track.

Which CarboTechs would you run for track? Seems like they are popular, but I'm a bit overwhelmed by the number of compounds they have.

 

[beastmode13]

Which CarboTechs would you run for track? Seems like they are popular, but I'm a bit overwhelmed by the number of compounds they have.

From my conversations with Drew of Martian Wheels, he said CT recommends XP12/XP10 f/r based on weight of the car. This was back in September when M3 pads was under development. I had ping him to check if he has gotten any Tesla user feedback on CT pads. From my own track experience, our cars have higher reliance on the rear brake then typical 4000lb cars. Having the same pad material front/rear is a better choice.

I have brake temp paint that I plan to apply to my rotors. Knowing what temp my rotors and pads are facing will be one data point to make an informed decision on XP10 or XP12.

Martian Wheels

 

[Dangerous Fish]

Just to add my experiences so far.

I've tried XT910 all round and XT970 all round at the same track on two different days. The track is not particularly hard on brakes but is about 1.8 miles long with 1 heavy braking zone and 3 other medium braking zones.
I'm driving in ambient temps. around 50 deg. F which I'm sure helps cooling somewhat. I'm still using stock rotors currently.

I found the XT910s had good feel but I got the temperature warning message after only a few laps and the pedal starting to go further to the floor. That's not fluid, as I've replaced the stock fluid with SRF. Measured rotor temperatures weren't excessive - around 400 C front and 250 C rear. All in all I didn't feel they were a significant enough improvement over stock, but would be fine for for 'fast street' driving or tracks without lots of heavy braking.

A couple of days ago I went back to the track with the XP970s in and this time no warning messages even after long runs. Temperatures were up to 500 C front and 390 C rear but no sign of fade or a long pedal and I think they had a much better feel all round. In comparison, there was another P3D+ running at the same time (completely stock) and he had front rotor temps >600 C and a long pedal after a few laps.
On the street, I'm more than happy with their performance as well. Even when stone cold, they stop the car well and so far I've heard no noise from them. I'm going to leave them in now for a while just to see how they do after more normal driving.

I'm not particularly worried about wear rates, I just want pads which work well and give good feel.

I can't easily get the Endless pads over here, so they aren't an option for me right now but TBH the XT970s seem to do the job and are a good price.

 

[destructure00]

From my conversations with Drew of Martian Wheels, he said CT recommends XP12/XP10 f/r based on weight of the car. This was back in September when M3 pads was under development. I had ping him to check if he has gotten any Tesla user feedback on CT pads. From my own track experience, our cars have higher reliance on the rear brake then typical 4000lb cars. Having the same pad material front/rear is a better choice.

I have brake temp paint that I plan to apply to my rotors. Knowing what temp my rotors and pads are facing will be one data point to make an informed decision on XP10 or XP12.

I'll keep an eye out for your experience and feedback. I pulled all my 910 pads today, front and rear, and they are all glazed over again. Fronts after 2 sessions yesterday, rears I have not checked since I put them on...they have 6 HPDE sessions on them. XT910s are definitely not sufficient for the track IMO.

Sanded the glazing off the pads, hit my stock rotors with an 80 grit flapper disc to get any old stock pad material off and reinstalled. Brake pedal feel is much firmer already. Still need to go bed the 910s into the stock rotors.

I also hit the RB rotors with the flapper disc, I think they were glazed as well. Those are cleaned up now and ready for whatever track pads I decide to go with.

I found the XT910s had good feel but I got the temperature warning message after only a few laps and the pedal starting to go further to the floor.

My experience so far is that this is a sign of glazed pads. Fresh pads don't heat up enough to set off the message, but once they glaze over, you are harder on the pedal, which causes more heat, which causes more glazing, on and on. At this point there's enough heat in the system to set off the warning. Mine got so bad on my first session yesterday that track mode shut off and I started getting warnings for stability control disabled, AEB disabled, hold mode disabled, auto pilot disabled, etc. Once everything cooled down it was back to normal.

If you get a chance, pull the pads and look at them. Here's one of my glazed ones today next to one that I sanded down.

 

[Dangerous Fish]

Oh yes, my 910s were glazed too. Haven't pulled the 970s yet but they were as good at the end of the day as they were at the start so I reckon they'll look OK.

 

[Lunares]

I'll keep an eye out for your experience and feedback. I pulled all my 910 pads today, front and rear, and they are all glazed over again. Fronts after 2 sessions yesterday, rears I have not checked since I put them on...they have 6 HPDE sessions on them. XT910s are definitely not sufficient for the track IMO.

Sanded the glazing off the pads, hit my stock rotors with an 80 grit flapper disc to get any old stock pad material off and reinstalled. Brake pedal feel is much firmer already. Still need to go bed the 910s into the stock rotors.

I also hit the RB rotors with the flapper disc, I think they were glazed as well. Those are cleaned up now and ready for whatever track pads I decide to go with.



My experience so far is that this is a sign of glazed pads. Fresh pads don't heat up enough to set off the message, but once they glaze over, you are harder on the pedal, which causes more heat, which causes more glazing, on and on. At this point there's enough heat in the system to set off the warning. Mine got so bad on my first session yesterday that track mode shut off and I started getting warnings for stability control disabled, AEB disabled, hold mode disabled, auto pilot disabled, etc. Once everything cooled down it was back to normal.

If you get a chance, pull the pads and look at them. Here's one of my glazed ones today next to one that I sanded down.

View attachment 477998

RB does specifically say that the 910s are not for track. Disappointing they get glazed so fast though

 

[zhu-]

If I'm looking for some additional bite just for street use, could I get away with only XT910 in the front or should I get it for all four? Does aftermarket pads affect the traction control systems at all? Thanks for the helpful info here!

 

[beastmode13]

If I'm looking for some additional bite just for street use, could I get away with only XT910 in the front or should I get it for all four? Does aftermarket pads affect the traction control systems at all? Thanks for the helpful info here!

910 has better bite than stock pad, read post #1. Front only is sufficient for your need. No, it does not impact TC.

 

[Dangerous Fish]

Before changing from the stock pads, make sure they are properly bedded in. This is the main reason new Model 3 owners complain about the brakes from what I've seen.

I didn't find properly bedded OE pads were much different from the 910s for street driving, especially when cold .

 

[zhu-]

910 has better bite than stock pad, read post #1. Front only is sufficient for your need. No, it does not impact TC.

Read the whole thread

The 970s sounded great until I heard the part about the squeaks. Has anyone tried pads from other companies like MPP, Unplugged, etc. ? I don't mind dust or short pad life since I don't use the brakes often but when I do I'd prefer them to have a much more aggressive bite - as long as squeaking can be controlled. I'm used to having to do some hard brakes to clean the dust off in my previous cars from time to time to get rid of the squeaks.

 

[beastmode13]

Read the whole thread

The 970s sounded great until I heard the part about the squeaks. Has anyone tried pads from other companies like MPP, Unplugged, etc. ? I don't mind dust or short pad life since I don't use the brakes often but when I do I'd prefer them to have a much more aggressive bite - as long as squeaking can be controlled. I'm used to having to do some hard brakes to clean the dust off in my previous cars from time to time to get rid of the squeaks.

You were asking about 910, which is a great pad for street. 970 is more track oriented, not intended for daily, it doesn’t have the bite at the low temp encountered for street driving.

 

[beastmode13]

This past Saturday, I tried Porterfield R4 with the front Racing Brake RB460 caliper. The weather ranged from overcast and mid 50's at 9am to partially sunny and low 70's by noon. I got three sessions before the drizzle started to fall. It was not the most challenge weather for brake by any means.

Feel wise, the R4 is more linear compared to XT970. XT970 has a progressive feel that I've yet to master, the friction level increases as the pad gets hotter in the braking zone. The friction bite of R4 is slightly less than XT970 but a bit more than XT910.
Below is a photo of Porterfield R4 after three sessions, not looking so good with lots of pitting and some glazing. About 1.5mm of the material was used. XT970 wears lot better than the R4.

Another big negative in my book about R4 is the brake dust specifically, how it sticks to the wheel. R4 was on the car for two days, one street day before the track, then the track day. The brake dust required some major scrubbing with a brush and green scotch pad to get it out.

Next season, I plan to try RB XR70, Endless, and some CarboTech.

 

[Lunares]

This past Saturday, I tried Porterfield R4 with the front Racing Brake RB460 caliper. The weather ranged from overcast and mid 50's at 9am to partially sunny and low 70's by noon. I got three sessions before the drizzle started to fall. It was not the most challenge weather for brake by any means.

Feel wise, the R4 is more linear compared to XT970. XT970 has a progressive feel that I've yet to master, the friction level increases as the pad gets hotter in the braking zone. The friction bite of R4 is slightly less than XT970 but a bit more than XT910.
Below is a photo of Porterfield R4 after three sessions, not looking so good with lots of pitting and some glazing. About 1.5mm of the material was used. XT970 wears lot better than the R4.

Another big negative in my book about R4 is the brake dust specifically, how it sticks to the wheel. R4 was on the car for two days, one street day before the track, then the track day. The brake dust required some major scrubbing with a brush and green scotch pad to get it out.

Next season, I plan to try RB XR70, Endless, and some CarboTech.


View attachment 486687

Another one bites the dust!

I'm a bit nervous at this point to track on the 910s. They work just fine for autox with the lower heat load but wondering if I should upgrade before buttonwillow/ streets of willow next year

Need to learn how to swap brake pads and bleed brake fluid anyway

 

[Dangerous Fish]

Next season, I plan to try RB XR70, Endless, and some CarboTech.


View attachment 486687

Which Carbotech compound are you going for?

Are you resurfacing the rotors each time you try a different pad?

 

[destructure00]

Another one bites the dust!

I'm a bit nervous at this point to track on the 910s. They work just fine for autox with the lower heat load but wondering if I should upgrade before buttonwillow/ streets of willow next year

Need to learn how to swap brake pads and bleed brake fluid anyway

After my experience I would not track the 910s. Not worth it, if you're aggressive at all they won't last the day before glazing over, which will ruin your fun.

 

[Dangerous Fish]

I agree about the 910s. Not a big enough improvement over stock.