Another brake question - Again!

[jamesjedi]

Do 3.6 conversion cars have to have bigger brakes than the 3.2 Carrera? My car is a race car build, but will honestly be used more for autocross. I have 996 brakes on it now, but they will not let me use 15 inch wheels.

So....do I really need bigger brakes? I know 930 brakes will fit, but I do live in a budget restricted world. There is not much in between the Carrera and the next size larger brakes.

So...if car is partly fiberglass, undercoating and sunroof removed, can the Carrera 3.2 brakes with attention paid to cooling and pads, do the trick for a race?

[Cajundaddy]

Smaller brakes might even be better for AX with less rotating mass and less unsprung weight. In most cases, if you can lock up your front brakes or put them into ABS, you have plenty of braking power. Then the question becomes heat dissipation which isn't really an AX problem.

If you are running DE or club racing and regularly cooking your brakes even with hi temp fluid, cooling ducts, and racing pads then you may need bigger brakes to dissipate more heat quickly during continuous lapping. A bigger motor certainly generates more speed at the end of a straight, but weight removal might neutralize the extra stopping power and heat sink needed.

[jamesjedi]

Thanks for the reply.

What is to be expected for a race? Has any one got a similar powered car (approx. 260rwhp...hopefully!) with these small brakes?

[Cajundaddy]

Originally Posted by jamesjedi

Thanks for the reply.

What is to be expected for a race? Has any one got a similar powered car (approx. 260rwhp...hopefully!) with these small brakes?

What does your car weigh with driver? What brake fluid, pads, and cooling measures are you using? If it were my car and I was setting up for club racing, I would choose 17" wheels for much better tire choices and leave the 996 brakes on the car since they are paid for.

[jamesjedi]

Such a good point - They are paid for!

I just need to just get it finished!

[Bill Verburg]

Originally Posted by jamesjedi

Do 3.6 conversion cars have to have bigger brakes than the 3.2 Carrera? My car is a race car build, but will honestly be used more for autocross. I have 996 brakes on it now, but they will not let me use 15 inch wheels.

So....do I really need bigger brakes? I know 930 brakes will fit, but I do live in a budget restricted world. There is not much in between the Carrera and the next size larger brakes.

So...if car is partly fiberglass, undercoating and sunroof removed, can the Carrera 3.2 brakes with attention paid to cooling and pads, do the trick for a race?

Most bbk's are used to handle heat, heat that just doesn't get generated in A/X or street use.

Stick w/ your stock brakes for A/X, remove the p/v to help the car rotate faster(this is not recommended for big track use)

[jamesjedi]

Thanks for the replies. As I interpret the replies: The Carrera or boxster brakes will not be enough for the 3.6 race car.

[KTL]

How much does your car weigh? Plavan has a seriously light, fast car with 2.5L and he runs the S brakes (similar to SC size, with lighter aluminum alloy front calipers) with Raybestos ST43 pads. Always says he's got no desire for more/bigger brakes.

Cooling and pads are key. Do the best you can to get air ducted to the rotors with hose (smooth/straight with minimal bends is important) and seal off the rotors to get the cooling air into the eye of the rotor and out thru the cooling vanes. Block off the gaps in the hub with these star plates or make your own. Welcome to Rothsport Racing - Chassis Products

Use true dedicated race pads that can handle the heat. You can also use tricks like titanium "shims" between the pads and pistons to reduce heat transfer into the fluid. Racers Edge Porsche Suspension Yeah I know those don't fit your Carrera pads but you get the idea.

[Walt Fricke]

So the issue is you can't fit the 15" rims your autocross class requires over your 996 brakes?

Well, if the autox class is what you need to deal with, you can find 4 piston calipers which will fit these rims and your brake mounts. Wilwood makes (or made) some, and there are some others. I use Bremtek's, which were an improved knockoff of Wilwoods, and long out of production, on my track GT car. 1960 lbs dry, about 200 more with me and the stuff. 250 rwhp from a 2.8. Never a brake problem on the track in DE or racing other than purchasing new pads more often than I would like - but that's just part of the game.

So you could have your brake and eat it too. Of course, I am careful about air ducting, and use high temp fluid.

[juanbenae]

Originally Posted by jamesjedi

, can the Carrera 3.2 brakes with attention paid to cooling and pads, do the trick for a race?

you should try that first. see if it suits your needs while racing & report back. I use effectively cooled Carrera set up front and stock SC rears, stock MC with gritty pads for effective longevity. rotors are cheap for the set up. there are guys in front of me with better brakes, & guys behind me with better brakes. #2400 w/ fat man abiding by spec class rules of 16" wheels from mid pack...

[juanbenae]

Richard checkin in...

get it finished with what your budget allows so you can actually drive the car on a track or around some cones. after a bunch of seat time watching all yir video look for where there is room for improvement. if eventually the car, or it's brakes are the weak link, very very good jedigrasshopper...... when yir really hooked a set of tires, brake pads, or event entry might be all we can afford Carrera brakes or not...

[jamesjedi]

Thanks for the replies. Got to get it finished.

Interesting to hear that it may be possible. But get it finished.

Thanks again.