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Per the Wilwood rep, I also got some BP-10 pads for the street and BP-20 for the track. Got it installed on Jan 10 and it looked pretty awesome!
Had my first track day with it on Jan 14 and...well...I did set a new PB by 1.5 seconds, so that's good. But it turns out the BP-20 pads weren't cut out for the track, lol!
Yes, those are *grooves* cut into the rotor. It seems the BP-20's were getting too hot and disintegrating! I could get the rotors turned, per my mechanic (they build race cars, so I trust them), but, I opted to just get new rotors. I want to give these a fair shot from "brand new". So, new rotors on the way along with new BP-10 and BP-30 pads for the track (per my mechanic). I should have another track day in a couple weeks, so we'll see how the BP-30's hold up, lol!
So you’re having problems with heat management and you move to smaller rotors?
Well, I'm having what I can best describe as "brake fade", which can be heat issues, pad knock-back, something else? Dunno. All I know is I didn't have any of these issues with my 2019 JCW with the JCW Pro brakes (it had the JB4 plugin so not too far off in terms of HP/Torque numbers). So I'm trying something completely different:
Different rotors that are 2 piece that will hopefully help with some heat management. And they're only 4-ish mm smaller, so not that much.
Vented rotors that might help with potential whatever problems vented rotors help with.
Different calipers that should have better heat management and anti-knock-back springs, which should help with that, too.
Different pad compounds, which, well....not as much luck on that, yet, lol! But I'm not giving up yet.
But yeah, I'm going to try everything I can until I can trust my brakes on the track again.
Well, I'm having what I can best describe as "brake fade", which can be heat issues, pad knock-back, something else? Dunno. All I know is I didn't have any of these issues with my 2019 JCW with the JCW Pro brakes (it had the JB4 plugin so not too far off in terms of HP/Torque numbers). So I'm trying something completely different:
Different rotors that are 2 piece that will hopefully help with some heat management. And they're only 4-ish mm smaller, so not that much.
Vented rotors that might help with potential whatever problems vented rotors help with.
Different calipers that should have better heat management and anti-knock-back springs, which should help with that, too.
Different pad compounds, which, well....not as much luck on that, yet, lol! But I'm not giving up yet.
But yeah, I'm going to try everything I can until I can trust my brakes on the track again.
They are 4mm smaller in diameter, but 2mm smaller in width. Plus, the total swept surface area of the Wilwood brakes is significantly smaller. I also know you were cracking the GP3 brake rotors, you definitely have a heat problem. Wilwood also doesn’t generally have the benefits you’re referring to. The GP3 rotors are directionally vented which is either as good or better than the wilwood kit you have. To make matters worse, the GP3 rotors with steel hats have more heat capacity than the two piece hats with the aluminum. The calipers on the GP3 are so big and heavy they likely have better resistance to knockback and Wilwood calipers are well known to flex (for their given size).
Could there be a software issue here? The car relies on the e-diff pretty significantly (to force the lsd to hook up), and seems like it could be the cause of your issue.
All that might be true, but the GP3 brake setup has given me nothing but trouble, so I'm trying something new because at this point, I'm tired of not being able to trust my brakes. And vented was the wrong word, I meant slotted. Which brings these rotors closer to the 2019 JCW Pro Brake rotors I had before (yes, I know still some differences).
I have a pretty good idea about why you are having problems, and it's your driving style.
I can provide some data to back up my reasoning for my belief, and I would be happy to share the background calculator with you if you would like to explore it further.
My first F56 was an S, and I specifically chose the JCW calipers because they take care of what was actually important, while the Wilwood makes the basic problems worse (so do the GP3 ones). First, all the rear brakes are exactly the same across the S/JCW/GP. For now, I will not go into detail on how I did these calculations, but I would be glad to allow you access to the document to test your own research. I am making some assumptions, and these assumptions can create drastically different numbers but in general, as long as they stay the same between these comparisons, It should be very little problem.
So I will start with the F56 S F56 Cooper S calculations.
When compared to the widely loved JCW brakes... the JCW brakes actually provide less piston area than the S, this makes the brakes feel better, it makes up for that with significantly larger rotors. This means the front brakes produce an additional 17% for a massive increase in heat capacity by 13% in brake diameter, not to mention increasing the width from 22 to 30mm (width increases don't translate 1to1) F56 JCW calculations
So now, I will provide you with the GP calculations... The rotors and pistons are both larger, resulting in a massive...22% increase in braking torque, with a minor 7% increase in brake diameter in capacity compared to your favorites.
F56 GP calculations
I don't have the whole calculations for your Wilwood kit, but initial calculations suggest that at 14" rotors, you're producing 3550 in.lbs with less pad volume, less rotor mass, and less performance. That's a problem.
What we are seeing here is that the GP3's brake torque (ability to create heat) far outweighs its ability to remove heat. It is my belief that your driving style overuses the brakes and doesn't rely enough on the GP3's ability to carry speed through the corners and you're overdriving the car.
I haven't ruled out that it's my driving style. I'm constantly working on my braking and "carrying speed" through the corners. Comparing my cornering speed to others shows me not that far off from faster cars with higher grip tires, though. Anyway, it's always a work in progress. However, I'm also not the only one experiencing brake issues with the GP3, so for now, this is the route I'm taking.
bp30 are what I use on the street... might want to look at dtc 70 or st43 / st45 / st47
I use st43 with my wilwoods and I get 8 trackdays out of them
also get some color changing paint, are you using ducts? Without ducting your rotors are going to get nuclear hot, like off the chart most brake companies use, on top of that doesnt the gp3 use that shitty brake fake lsd ? that adds a ton of heat on corner exit where the rest of the cars are already starting to cool off.
ignore anyone that says you brake too much from entry to apex, they are probably failing to use all grip (they are failing to trail brake)
After this particular track day, I went to visit Todd at TCE. Like, literally after. I still had the pads and rotors on the GP3. Told him what was going on, he inspected the car and suggested the BP-30's. I'm assuming it's because it's not a dedicated track car (it's my daily-driver as well) and I wanted to be able to swap pads easily. I will be paying *very* close attention on my next track day, though, lol!
The GP3 has a mechanical LSD, but I'm not familiar with how it interacts with DSC and everything else.
I had the Wilwood temp stickers on the original GP3 calipers. They didn't show the calipers getting too close to the max temp on the sticker, though. What kind of heat do you mean by "off the chart"? I do have ducts, but I'm honestly not sure how useful they are. I've had 2 performance shops tell me they should work well, but...This is the one I have: https://advancedautofab.com/p/jcw-mi...rake-duct-kit/
After this particular track day, I went to visit Todd at TCE. Like, literally after. I still had the pads and rotors on the GP3. Told him what was going on, he inspected the car and suggested the BP-30's. I'm assuming it's because it's not a dedicated track car (it's my daily-driver as well) and I wanted to be able to swap pads easily. I will be paying *very* close attention on my next track day, though, lol!
The GP3 has a mechanical LSD, but I'm not familiar with how it interacts with DSC and everything else.
I had the Wilwood temp stickers on the original GP3 calipers. They didn't show the calipers getting too close to the max temp on the sticker, though. What kind of heat do you mean by "off the chart"? I do have ducts, but I'm honestly not sure how useful they are. I've had 2 performance shops tell me they should work well, but...This is the one I have: https://advancedautofab.com/p/jcw-mi...rake-duct-kit/
you need rotor paint it's the rotors that are getting too hot, not the calipers. The paint changes color I would paint at the rotor edge and also near the hub
I daily drive my track car too but I have to change pads before a track day, street pads simply do not work on the track unless you are slow/suck at driving.
those ducts have too many bends, I tried ones like that and they did not work for me at all, no change in pad/rotor life and testing with a airflow meter showed they were awful, every bend is a drastic drop in flow I think it's basically inverse square law. I ended up removing the backing plate and making a very short duct that goes from the front bumper just into the wheel area to point at the hub from the front of the A arm. Very short with less bends. Resulting change was twice as much pad life and less cracking on the rotors. Pads were and unfortunately still are my #1 consumable cost on both my mini's and my bmw track cars
