rear brake rotor upgrade

[speedman]

I have installed the 964 calipers and 28mm fronts and now I have to attack the rears. Any suggestion on rear rotors

[wwest]

Leave them be.

[Bill Verburg]

Originally Posted by speedman

I have installed the 964 calipers and 28mm fronts and now I have to attack the rears. Any suggestion on rear rotors

The easiest is to use '84-89 3.2 Carrera wide m's and their 24x290 rotors

It may be possible to use 964 rear calipers on 24x299 996 rear calipers. I'm not sure yet but have a set on my bench that I've been meaning to experiment w/

[speedman]

my plan is to use 24mm x 200mm 964 rear rotors and modify what I need to so they will work. I will let you know if it is possible

[Bill Verburg]

Originally Posted by speedman

my plan is to use 24mm x 200mm 964 rear rotors and modify what I need to so they will work. I will let you know if it is possible

the 964 rears are 24x299

here's a pic of some rear rotors, from the left 993(24x299, 964 is the same except for a slightly different o/s), 996(24x299) and 911(20x290)


as you can see the o/s are all different which will preclude use on a 911.

The 3 rotors that I know will work on the back of a 911 are
911'69 - 83 20x290
911 '84 - 89 24x290
930 '78 - 89 28x309

I've used the 930s w/ 964 rears


here's a pic of the caliper mods on mine, holes relocated and throat relieved


VCI does it a little differently, they remove the stock mounting ears and convert the caliper to radial mount

[speedman]

in your last picture are those 930 rotors? I have access to a full shop so machining is not a problem. I just don't want to drill a hole in the wrong location and hit Hyd. oil. I have put 28mm x 298mm on the front and want the most out of the brake upgrade. I am not doing it for looks since I will be adding a Modified 3.6 soon. If you get too much rotor in the back will adversely affect braking?

[johnsjmc]

Right now you have too much front bias. You can,t have too much rotor but you have a larger piston area up front than before . I would use stock 24 mm Carrera rear rotors and the matching Carrera rear caliper . They look almost the same as SC but are wider and have a bigger piston and will restore appropriate front rear brake force ratios . I think still slightly greater front which isn,t a bad thing with good traction.