Quote:
|
Originally Posted by mike_sho
Street driving does not require more heat capacity. It requires more initial bite for safety. Highway or high-speed driving does though, perhaps thats what you meant.
|
Street driving includes highway and some high speed use. For some, it also includes long descents with extensive brake use, for which most people don't practice a proper braking technique and thus create a lot of heat.
Quote:
|
Otherwise auto-cross requires more , but it also depends on the course. Some courses you can get away with very little braking , others theres a lot of it. So thats hard to say either way.
|
It is course dependent, however in general you don't need a lot of heatsink capacity at all for autocrossing - however you do need a friction material with a broad operating temperature range and stable bite curve, good modulation characteristics, and a high enough friction coefficient to lock the tires that you're using. The stock brakes with an upgraded friction compound are almost always plenty for most cars.
Most national-level autocross cars are not using massive brakes. A purpose-built autocross car will almost always have the smallest brakes allowed by rules to save weight. As an example, the highest-finishing Honda in Street Modified for several years running - owned and driven by Chris Travis - has been an EH3 Civic hatchback with stock 9.5" vented front rotors and the small unmarked Civic calipers, coupled with rear drums from a non-Si/non-ABS model. Travis actually had been using 5-lug ITR brakes (11.1" vented front rotors with 17CL15VN calipers and 10.2" solid rear rotors with 9CLP14S calipers) previously, but converted back to the smaller 4-lug brakes for a significant weight reduction.
As I've explained before, you can't approach autocross with the same mentality that you would drag racing, street driving, or track days, because there are fundamental differences in the way the cars are used, in what is necessary for the car to do what you need it to do, and for competition applications, in what is beneficial to reducing times.