Keepig tabs on brake caliper temps at track

[USSEnterprise]

This is after 2 full sessions, ~20 laps or so. MPS4S tires (300TW). CCB calipers but system converted to giro disc steel rotors and DS1.11 pads. It was a cool day with ambient temps in low 50s. WINDY as hell.



The 6 piston calipers must run cool, didn't even register temp both on outside as well as middle of the calipers. Rears run about 280-320 which makes sense since I leave MDM on so its probably traction control working. Rear passenger got hotter than rear driver which must be because of my track's specific layout of left vs right handers.

Interesting data.

[sly1types]

cool

[sc_tr0jan_m3]

Sheesh. I get more temps into my lighter e46! That's a bit weird...

[USSEnterprise]

Originally Posted by sc_tr0jan_m3

Sheesh. I get more temps into my lighter e46! That's a bit weird...

I got 19 sessions out of my previous set of front brake pads (Carbotech XP12s). Rears have 23 sessions on them and worn about half way. Running 2:10-2:11s at ECR. This is with MDM left ON so I would assume pads are seeing a fair bit of use. Pad wear seems to correspond to the low temps in the calipers.

Of course with r-comp tires and on a hotter day when I'm going much faster (hopefully), I would assume caliper temps would be hotter. However, in my experience so far, the F80 brakes are proving to be very well engineered. Out of the box.

[sc_tr0jan_m3]

Originally Posted by xxaarraa

I got 19 sessions out of my previous set of front brake pads (Carbotech XP12s). Rears have 23 sessions on them and worn about half way. Running 2:10-2:11s at ECR. This is with MDM left ON so I would assume pads are seeing a fair bit of use. Pad wear seems to correspond to the low temps in the calipers.

Of course with r-comp tires and on a hotter day when I'm going much faster (hopefully), I would assume caliper temps would be hotter. However, in my experience so far, the F80 brakes are proving to be very well engineered. Out of the box.

Nice! Let's compare next time we're out together. You might be right saying that the e46 brakes just suck.

[DRLane]

Originally Posted by xxaarraa

I got 19 sessions out of my previous set of front brake pads (Carbotech XP12s). Rears have 23 sessions on them and worn about half way. Running 2:10-2:11s at ECR. This is with MDM left ON so I would assume pads are seeing a fair bit of use. Pad wear seems to correspond to the low temps in the calipers.

Of course with r-comp tires and on a hotter day when I'm going much faster (hopefully), I would assume caliper temps would be hotter. However, in my experience so far, the F80 brakes are proving to be very well engineered. Out of the box.

So 8-9 track hours, seems reasonable wear rate. Do you have a speed trace of your faster laps? Pick up some heat paint and mark the rotors, that'll be a good indicator for pad selection.

The calipers looks fantastic and the monster rotors should be a decent heat sink. Running r comps with some more pace will start to highlight their weaknesses, but I believe the caliper will at least start to heavily discolor pretty by that point.

[nicknaz]

Originally Posted by xxaarraa

The 6 piston calipers must run cool, didn't even register temp both on outside as well as middle of the calipers. Rears run about 280-320 which makes sense since I leave MDM

Just my $0.02 but if you are using mdm in the dry, and not heating up the front rotors, is it time for r comp?

Consider Dsc off with street tires for a while and see if there are opportunities to heat up the front brakes with more aggressive threshold braking at entry?

Cool pics, and great looking rotors!

[RSXDC5]

Good stuff man. Next try mdm off, you'll probably knock off a few more seconds. After that get harder on the brakes to find more time, after you are comfortable at that pace...let's talk tires!

What suspension are you on?

[USSEnterprise]

Ran 4 sessions today with Hoosier R7s. DSC completely off. Cold day, was in the low to mid 40s. To put my pace in perspective, I was running about 5 seconds slower than GT3s at my local track.

Got the front calipers up to 320 or so degrees, but still runs much cooler than I would have thought. Very happy with F80 CCB calipers.

[thefilipaneseboy]

How's the noise when the DS1.11s get up to temp? When I was bedding they were squealing so bad that it was unbearable. Specifically the rears since I used DS1.11 fronts/ DS2500 rears and I'd be able to manage with them on for a few days after the track since the squeal was very tolerable compared to now with the DS1.11 rears

[sc_tr0jan_m3]

i run 1.11's in an ap racing kit up front and they have zero noise on the track or even driving around town.

[USSEnterprise]

I agree with SC_Trojan above. I have zero squeal and dust seems very manageable also. I run Girodisc rotors so not sure if that contributes.

[NYG]

That's weird af.

Those are my temps with AP 9660s at the Glen 55F.

[USSEnterprise]

Originally Posted by NYG

That's weird af.

Those are my temps with AP 9660s at the Glen 55F.

How big are your rotors (they look kind of small?) One possible answer is the 400 mm F80 rotors have a much larger area to dissipate the heat (as well as extra cooling vanes built into the girodisc rotors - im not sure thats the case but im speculating?)

Piston design and diameter also contribute to heat in the caliper. On my race bikes, I upgrade the aluminum Brembo pistons to aftermarket stainless pistons (Braketech) that cool better and allow for more fluid in the system. We'd have to compare the F80 CCB caliper's pistons to the AP caliper and its pistons.

[NYG]

Originally Posted by xxaarraa

How big are your rotors (they look kind of small?) One possible answer is the 400 mm F80 rotors have a much larger area to dissipate the heat (as well as extra cooling vanes built into the girodisc rotors - im not sure thats the case but im speculating?)

Piston design and diameter also contribute to heat in the caliper. On my race bikes, I upgrade the aluminum Brembo pistons to aftermarket stainless pistons (Braketech) that cool better and allow for more fluid in the system. We'd have to compare the F80 CCB caliper's pistons to the AP caliper and its pistons.

372X34MM AP 2-pc Rotors with vented stainless steel pistons.

There is a larger surface area on 400MM rotors but because the F8X has zero airflow to the brakes, it'll also hold more thermal mass.

My stock iron calipers reached 700-800F - it's why I had to change them.

I ran DSC Off with DS3.12s.

Do you threshold brake? Toyo RRs were definitely putting more heat into my brakes than MPS4S would but not registering even 250F in the front is highly sus. The stock calipers/lack of airflow are a heat loving combo. Even if the girodiscs helped cool the rotors, the caliper will have a hard time dissipating that heat. They're terribly designed for track use.

[USSEnterprise]

Originally Posted by NYG

372X34MM AP 2-pc Rotors with vented stainless steel pistons.

There is a larger surface area on 400MM rotors but because the F8X has zero airflow to the brakes, it'll also hold more thermal mass.

My stock iron calipers reached 700-800F - it's why I had to change them.

I ran DSC Off with DS3.12s.

Do you threshold brake? Toyo RRs were definitely putting more heat into my brakes than MPS4S would but not registering even 250F in the front is highly sus. The stock calipers/lack of airflow are a heat loving combo. Even if the girodiscs helped cool the rotors, the caliper will have a hard time dissipating that heat. They're terribly designed for track use.

I can't speak to regular F80 calipers or rotors, I'm only sharing experience and data related to CCB calipers. Tires and brake pads I'm using are in my posts above. 370mm to 400mm is a huge difference in surface area regardless of the specific caliper in use.

I'm not the fastest driver out there by a large margin, however, those temps are from a car running within 5 seconds of GT3s on a 2+ minute lap so I'm not put-putting out there either and car sees a good workout.

I don't subscribe to the zero airflow hypothesis. Sure it has no ducting but there are functional vents at the edges of the bumper that direct air to the outside of the rotor/caliper. I don't imagine my CS front bumper is unique and even base/comp M3s have the same vents, but I could be mistaken?

Keep in mind my data is also from winter time track days with temps in the 40s. On a 90 degree Texas summer day, I'm sure the calipers will heat up more. And as they do, I will share in this thread. Please continue sharing your data as well including your specific setup as you did, helpful for folks to get more data.

[DRLane]

Originally Posted by xxaarraa

I can't speak to regular F80 calipers or rotors, I'm only sharing experience and data related to CCB calipers. Tires and brake pads I'm using are in my posts above. 370mm to 400mm is a huge difference in surface area regardless of the specific caliper in use.

I'm not the fastest driver out there by a large margin, however, those temps are from a car running within 5 seconds of GT3s on a 2+ minute lap so I'm not put-putting out there either and car sees a good workout.

I don't subscribe to the zero airflow hypothesis. Sure it has no ducting but there are functional vents at the edges of the bumper that direct air to the outside of the rotor/caliper. I don't imagine my CS front bumper is unique and even base/comp M3s have the same vents, but I could be mistaken?

Keep in mind my data is also from winter time track days with temps in the 40s. On a 90 degree Texas summer day, I'm sure the calipers will heat up more. And as they do, I will share in this thread. Please continue sharing your data as well including your specific setup as you did, helpful for folks to get more data.

The 400mm is huge, do you know the thickness of the rotor? I wouldn't necessarily say it's a night and day more effective heat sink than the AP 370x34. But I have no experience with girodisk. I know a lot of m2c at my track run into constant trouble with those yellow calipers.

Also, in the spirit of sharing meaningful data would be helpful to see a speed trace from your faster laps.

[USSEnterprise]

Originally Posted by DRLane

The 400mm is huge, do you know the thickness of the rotor? I wouldn't necessarily say it's a night and day more effective heat sink than the AP 370x34. But I have no experience with girodisk. I know a lot of m2c at my track run into constant trouble with those yellow calipers.

Also, in the spirit of sharing meaningful data would be helpful to see a speed trace from your faster laps.

Sure. Here is the equivalent of a speed trace from the Garmin Catalyst. I can't find a better way to export a speed trace so if anyone knows let me know.







To gauge a 2:08/2:09, you can simply search on youtube for "Eagles canyon gt3" so you don't have to take my word for it. Majority of the fastest road cars around ECR now happen to be GT3s/GT3RS/GT2RS, hence the benchmark.

Regarding thickness of the rotor, I can't seem to find it on girodisc's website. I know it doesnt mean much but minimum thickness stamped on rotor is 34mm. Here's a weight comparison of them when I replaced the CCB rotors (they are ridiculously heavy).

[DRLane]

Originally Posted by xxaarraa

Sure. Here is the equivalent of a speed trace from the Garmin Catalyst. I can't find a better way to export a speed trace so if anyone knows let me know.

[IMG]https://lh3.googleusercontent.com/pQ...tLqWXgkI=w2400[/IMG]

[IMG]https://lh3.googleusercontent.com/60...GWV74p7o=w2400[/IMG]

[IMG]https://lh3.googleusercontent.com/6_...s1WIcu54=w2400[/IMG]

To gauge a 2:08/2:09, you can simply search on youtube for "Eagles canyon gt3" so you don't have to take my word for it. Majority of the fastest road cars around ECR now happen to be GT3s/GT3RS/GT2RS, hence the benchmark.

Regarding thickness of the rotor, I can't seem to find it on girodisc's website. I know it doesnt mean much but minimum thickness stamped on rotor is 34mm. Here's a weight comparison of them when I replaced the CCB rotors (they are ridiculously heavy).

Those rotors looks awesome! Yeah not the best view for a speed trace but without a Solo type lap timer that might be the only option. Honestly it's hard to discern much from those squiggles. 😬

A look at NASA time trials at ECR last November in the TT2 and TT3 which is where the f8x would likely land. The fast laps are 1:53, 1:55 respectively. Looks like anything sub 2 mins is cooking... So you likely have a lot of room to progress with that setup.

[USSEnterprise]

Originally Posted by DRLane

Those rotors looks awesome! Yeah not the best view for a speed trace but without a Solo type lap timer that might be the only option. Honestly it's hard to discern much from those squiggles. 😬

A look at NASA time trials at ECR last November in the TT2 and TT3 which is where the f8x would likely land. The fast laps are 1:53, 1:55 respectively. Looks like anything sub 2 mins is cooking... So you likely have a lot of room to progress with that setup.

Can you show me where you are looking?

Here?

https://racehero.io/events/nasa-texa...aceway/results

Not seeing any 1:53s, the fastest laps I'm seeing are 2:02s.

[DRLane]

Originally Posted by xxaarraa

Can you show me where you are looking?

Here?

https://racehero.io/events/nasa-texa...aceway/results

Not seeing any 1:53s, the fastest laps I'm seeing are 2:02s.

https://nasatx.com/wp-content/upload...s_2020-Jan.pdf

[RSXDC5]

Hey all,

I have these 400mm Girodisc rotors as well, the radial depth is 3in for those who asked...massive thermal batteries! These rotor's vanes cool exceptionally well compared to the carbon rotors & the bulk of the cooling gains we are seeing are from the rotor vanes acting as air pumps.

The massive pads are also a benefit for brake temp management!