One more on the bandwagon. I have the ST40 kit on the current racecar and check after every event but pad thickness barely changes.

Bought the C43 kit for the new racecar because I'm going for minimum weight. However, for a trackday car not trying to meet a stupid low class minimum weight I'd follow the advice above.

 

I’ve been following this.

I use stock rears, giro disc fronts and the accord pad. Brakes last a 30-45 min sprint race without issue. Temps are very high. 800+C both front and rear with gloc r16/r12 pads. I eat rears after 2 events. Front wear seems better since using the accord of and the giros keep temps down quite a bit.

ive been looking at c43/42 kits but my rules require me to add 50lbs. It might be worth it.

 

Get the ST40 kit over the C43.

I'll leave this here - fast forward to 11:10 mark. Anecdotal, yes - but, add that to the accelerated consumables wear compared with the ST40, and it's another reason for me to stick with the tried and trued ST40 kit. Add on top of it the cheaper ST40 purchase price compared with the C43, and it really does sound like the C43 kit is a bunch of hype....

 

ive got the c43 kit, i'm 4 track days in with hardly any pad wear. im running ducts front and rear with urge rears. i also find the track pads noisy but i am using the stoptech 309 streetpad when not at track and they're pretty much silent. the street pads are chamfered at the leading edges, i wonder if that helps,

 

So i just picked up a set of used st40, what i found interesting was the rotors i got have full float hardware, they make quite a bit of noise. I originally thought it was something wrong until i did some measurements and found the nuts stick out pretty far to allow the rotor to float. Kind of makes me wonder since the rotor holes are oblong, that this constant back and forth will elongate the holes even more.

The c43 rotors are a full float as well which makes me wonder if the design is really safe considering his rotor exploded

 

As far as I’m aware floating rotors are industry standard. The oblong holes are to allow expansion and contraction of the material with heat since brakes get hot. Theoretically they should always naturally center themselves regardless of the rotors bolt opening size as long as the hat is circular no? Also ST40s used to be cheaper but now they’re priced almost the same as C43 kits at most places.

 

You can match them with Wilwood fronts too, as long as you get the appropriate piston size (41mm iirc, with 38mm being a good match for stock rears).

 

I had hoped that the Wilwood fronts would give me better wear than the ST40 due to the thicker pads. However I'm finding due to the smaller area of the pads, I tend to get significantly more top to bottom taper that I did with the ST40s. So brake feel is great for basically one event, and after that I have a fairly deep pedal because I effectively have to press the tapered pad flat onto the rotor. I'm going to try moving up to a higher compound to see if that helps, but yeah, so far that's been the one downside of this setup - considerably better pedal feel with the ST40s. However they ST40 kit doesn't match the SBG rears.

I wonder if there's an AP Racing caliper I could use with these AP front rotors that would have similar clamping force to the 41mm Wilwood, but a larger pad.

Edit: ah, there is a comparable AP caliper, but unsurprisingly it uses the same pad: https://www.essexparts.com/cp8350-tr...right-anodized. Guessing performance would be similar.

Edit again: I suppose the first thing I should try are some different pad compounds. I've been running GLoc R10s since I like to use the same pad for autocross, track, and driving to-from. Have an R12 that I was planning to try out already, but if that still tapers too much, might experiment with something different, like Raybestos ST43 or even ST47...

 

Valid points to consider. Thanks

 

I use 309's as well and I think they're great! They can take a beating and when hot they really come alive which takes some doing on the street