i_love_cars said:
that's cute, considering I run hot laps in my 135i with stock brakes and never have any issues after 6 or 7 30 minute sessions in a given day. Stock brakes on these cars are not racing brakes, but to make ignorant assumptions about how durable they are at the track is a step too far.
I have 6-piston calipers in front but I also know that the rotor heat dissipation is not as ideal as it could be, and the caliper pistons are actually made of a shitty cheap material that has actually started on fire and melted on some 135i's at the track. I know the weaknesses of stock brakes on cars as they get heavier because stopping so much weight will generate a ton of heat. There is definitely a limit but you are grossly exaggerating the limitations of the stock brakes on these cars based on their weight.
You are talking as if they are completely incapable of repeated track use. I've never seen a late-model BMW side-lined at the track due to brakes overheating. Ever. 98% of people buying a new M and tracking it will not have the skill to push the car to such a limit where the brakes would actually overheat and fail.
I don't want to discount the fact that a lighter car with good brakes will allow you to brake a lot later before turn-in - there's a reason people love Miatas at the track. I'm not saying you don't have a valid point - I'm saying you are overstating limitations of modern brakes on a car like a BMW M. 2 sessions and being sidelined is laughable.
Maybe it's driver, maybe it's not. My cars are relatively light. In 10 years of regular track duty I've seen e46 m3's and newer have brake problems every track weekend. The cars that don't typically have aftermarket kits on them. I've seen it in Intermediate and Advanced run groups, typically the instructors know by then that the stock brakes aren't worth the hassle and have upgraded.
I saw your car at the BMW club weekend at Road America -- didn't you see any prorblems? One guy ran home for rotors, another needed brake pads -- it's totally common on a hard driven e46+.
I'm glad your experiences have been different, but as you push your car harder I expect you'll probably see what I mean.