I have a pair of Boxster rears going
Dirk

What rotors do you run with the Boxster kit - Carrera rotors?

yep

Doesn't seem like you'd get much running Carrera rotors, even with Boxster calipers. Heat is the enemy, and you're going to want some bigger heat sinks than those Carrera rotors.

If you're looking at a 3.6 motor, I think you should be looking at more than Carerra rotors. Big reds from a 97 TT are pricey, but they sure stop good.

I agree. Thing is, 'big' brakes require big wheel, which require big budget. Too many big's for this po' boy.

:?

This is a really tricky issue. I'll try to make this short.

Imagine the most monster rotors and calipers available installed on one car, and stock rotors and calipers on another. Both cars the same - lets say 85 Carrera, on the same tires [very important].

Which car will stop quicker? In fact, both will stop in exactly the same distance from a given speed assuming threshold braking. Threshold braking is taking the tires to a point where they are just short of exceeding their frictional limits and locking up.

Urban Myth #1: Big brakes stop better. Its a myth. Braking effort is determined by the friction limits of your tires. The stock Carrera brakes are just as capable of locking up the wheels as the monster brakes, and lockup happens at the same point, given the same tires.

The larger brakes simply provide a better heatsink. They will retain effectiveness after the stock brakes have started to lose effectiveness due to heat buildup.

Question #1: Does a DE session in, say White run group take the stock brakes to the point where they lose effectiveness?
Stock brakes in good condition and decent brake pads will be very effective for the 20 minutes of a typical DE session. They will be even better with a typical ducted brake cooling setup.

Question #2: Will the same brakes last for a 90 minute enduro race?
No, the additional heat dissipation of the monster setup makes a huge difference in maintaining braking effectiveness over this longer period.

OK, thats longer than I intended, but you get the idea.

- If stock brakes are capable of locking up the wheels, then larger brakes will not provide more braking effort.

- If the duration of the event is suffiecient to bring stock brakes to the point where they can no longer dissipate the heat generated by the braking effort, then larger brakes will help.

Obviously, the Beast has 930 brakes (duh) and way more get up and go than a stock 3.6 (but not the gearing, which makes more of a difference on terminal velocity). At VIR I didn't feel I needed more brakes, just more SKILL using what I had. In comparison, I have Carrera calipers on the "T" with PF97 pads and have found myself wanting more stopping power.

The nice thing about the 930 conversion is that it fits inside 15" wheels.

Hear that, Jim! :D

Too wild for me. When I wanna go big time, I'll convert from M calipers to S calipers. A little bit more brake and a little bit less weight. My biggest braking improvements will come from learning when to start braking and how to modulate the brakes into/thru a turn. I have lots of room for improvement.

Amen :!: Brother Dorki has seen the light ... :lol:

Jase