Stoptech C43 front BBK

[M3tro81]

I remember a short thread discussing the C43 kit as a good option for the e46 M3 back on m3f. Has anyone had experience with it? Seems like a good upgrade from stock even if only 332mm rotors. The guys at BW explained that the whole system has significantly more thermal capacity even though the general consensus is that 355mm rotors are what this car needs for track duty.

I never experienced overheating of my stock brakes (PFC DD V3 rotors, PFC 11, ss lines, brass guide bushings) once I installed the cooling ducts. In fact I’m pretty sure that I was overcooling during a cooler track event on the long straights - pads were def below op temp after the straight and encountered some big chunking only after a couple sessions. Point is, I don’t think I’ll have an issue cooling the fronts.

There’s a great deal on the C43 kit right now and I’d like to move into something more dedicated to track use. Any thoughts, for or against are appreciated.

[Slideways]

It looks like a solid kit. I know that their painted street calipers are not great for dedicated track use. 332mm should give more choices for wheels and are probably lighter than the 355mm. What is the difference in cost versus a 355mm Brembo or AP Racing setup?

[M3tro81]

With the special they are running right now it’s about $1000 less than an AP kit

[Slideways]

With the special they are running right now it’s about $1000 less than an AP kit

That is a pretty good savings. After looking more at the spec though, my only concern is that the pad shape is unique. Pad selection might be limited with these. One of the other kits with a common pad shape might be cheaper in the long run.

[eacmen]

I remember a short thread discussing the C43 kit as a good option for the e46 M3 back on m3f. Has anyone had experience with it? Seems like a good upgrade from stock even if only 332mm rotors. The guys at BW explained that the whole system has significantly more thermal capacity even though the general consensus is that 355mm rotors are what this car needs for track duty.

I never experienced overheating of my stock brakes (PFC DD V3 rotors, PFC 11, ss lines, brass guide bushings) once I installed the cooling ducts. In fact I’m pretty sure that I was overcooling during a cooler track event on the long straights - pads were def below op temp after the straight and encountered some big chunking only after a couple sessions. Point is, I don’t think I’ll have an issue cooling the fronts.

There’s a great deal on the C43 kit right now and I’d like to move into something more dedicated to track use. Any thoughts, for or against are appreciated.

I ran the old 332mm ST40 kit and was cracking rings way too frequently. And they aren't cheap. Braking was solid though.

Not sure what they changed with the C43 kit. But personally I would opt for 996 conversion so the rotors are cheap or get a bigger front rotor.

[elbert]

After looking more at the spec though, my only concern is that the pad shape is unique. Pad selection might be limited with these. One of the other kits with a common pad shape might be cheaper in the long run.

Pad used is the same as Wilwood Superlite calipers, so plenty of options are available.

[Jevi Javi]

I was running the stock brakes (with PFC 08 pads, hardmotorsport brake ducts, ss lines and brass guide bushings) and switched late last year to the C43. I think i only have done 2-3 tracks days with the BBK. Have not been able to do long sessions due to unrelated problems. So not much to tell,. But so far so good. It stops as well or better than the stock brakes. I have kept the brake cooling ducts with C43 BBK but now Im thinking that i could ditch the ducts and run bigger tires up front. 275s. I dont know if pad choices are limited. But they are way cheaper. A set of PFC 08 pads for stock brakes cost like $330 vs $141 PFC pads for the C43.

[Slideways]

Pad used is the same as Wilwood Superlite calipers, so plenty of options are available.

That's good. I did not recognize the pad shape.

[eternaln]

I have these and they stop well for the size/weight of the calipers. Not as much stopping power as the trophys, but enough for your typical HPDE. The big advantage is obviously the weight.

My pads are almost done, does anyone know the pad shape for the Wilwood Superlite calipers mentioned above?

[elbert]

My pads are almost done, does anyone know the pad shape for the Wilwood Superlite calipers mentioned above?

Hawk HB521
PFC 7751
According to Bimmerworld

Wow those pads are cheap.

[CrookedCommie]

Hawk HB521
PFC 7751
According to Bimmerworld

Wow those pads are cheap.

PFC 7751 is also used for the AP CP8350, so maybe the same pad shape?

Rudy,

Thank you for reaching out in regards to pads for your brake kit. Our pad for the CP8350 is the 7751.XX. 20.44 which is available in our 01, 11,14 and 90 compounds. For road race/track day use on an a R comp tire I would recommend the 11 or 90 compounds which would be available for purchase through dealers such as Bimmerworld.

JC

Justin Cockerham
Motorsports Manager

[eternaln]

I e-mailed stoptech and they indicated that the pad shape is DR98, or DR21 wide annulus. The dimensions differ than either of the Hawk and PFC shapes discussed above. See below for the dimensions they sent me.

[elbert]

PFC 7751 is also used for the AP CP8350, so maybe the same pad shape?

Looks like it. Nice find! It's great they're using a common pad shape.

Not sure why a previous post said the price difference was $1000 from the AP kit. With the Bimmerworld discount, front C43 is $2271. Essex has the CP8350 at $2599.

[elbert]

I e-mailed stoptech and they indicated that the pad shape is DR98, or DR21 wide annulus. The dimensions differ than either of the Hawk and PFC shapes discussed above. See below for the dimensions they sent me.

I missed this earlier.
AFAIK (which isn't much), PFC and Hawk don't offer a DR21 pad but instead recommends HB521 and 7751. Not an exact match but probably close enough to work. Looks like there might be some unswept area though.

[CrookedCommie]

I missed this earlier.
AFAIK (which isn't much), PFC and Hawk don't offer a DR21 pad but instead recommends HB521 and 7751. Not an exact match but probably close enough to work. Looks like there might be some unswept area though.

It's similar with the AP kit. Some pads are full sweep, the rest are smaller. I switched to Ferodo pads that have the bigger radial depth.