BigRed calipers on a 930- 993TT rotor?

[sc]

Does anyone know if the 993TT front rotors with Big red calipers fit on a 930.
Thanks

[garrickl]

Yes they do. I have this setup on my 1978 930. Purchased the rotor hats and caliper adapters from Race Technologies

http://www.racetechnologies.com/

[sc]

Thanks for the response Garrick, I want to use the complete 993tt factory rotor and hat assembly with the 930 hub. Any other suggestions?

[nick-moss]

Have a look at Bill Verburg's site

[AES]

I really don't know the answer to your questions but from reading here and at Rennlist the 993TT rotors are 1 piece with a built in offset. I would be concerned that the rotor offset was not appropriate. The aftermarket rotors on the other hand all seem to use 2 piece rotors/hats with the hat incorporating the offset.

[garrickl]

You cannot use the factory 993TT hat on your front hubs. You need a custom hat to make it work. The 993TT rotor is 2 piece. The 993TT rear rotors are one piece and you can use them on your rear hubs .... however, a small portion of the parking brake shoes will extend past the 993 parking brake drums .... the parking brakes still work.

[Dallas]

I hate to show my ignorance, but what exactly is the rotor hat?

Thanks Dallas

[garrickl]

GO to Vehicle Craft's website and you can see and learn how big red modifications to older vehicles can be done.

http://www.vehiclecraft.com/Brakes/vciweb4.htm

[Bill Verburg]

You don't say what year 930 you have. The hubs for 78-79 are different from the later hubs. For a 78 or 79 hub you will want to use a flat(no offset) al. hat and 993tt size 322x32mm rotors with the stock front spacer. The later hubs are different and use a 304x32mm rotor w/ an integral 25mm o/s these can be used on all 911s w/ 9" front flares(ala Thom F.) but not w/ Big Red calipers

The 993tt and 993RS used the same rotors these can be either very heavy 1 piece 322x32mm w/ ~25mm os or much nicer(more $$) 2 piece w/ an iron hat which has the o/s. The aftermarket is utilizing the 2 piece rotors by taking the iron hat off and bolting their own al. hat in its place. In this way they can use the 322x32mm 993tt rotor on almost any 911 w/ 17' rims. Here is a pic of the more common 1 piece unit;


Here is a pic of the 2 piece iron/iron unit;


Here is a pic of Rattlesnakes 322x32 rotor w/ al hat on a (I think?) 911hub


The Race Technology front kit is one of the nicer kits available(It is available here at Pelican for a better price than most other places offer). However their rear kit leaves a lot to be desired. In the back I would use 78-89 930 309x28 mm 1 piece rotors w/ integral parking brake. This rotor works perfectly w/ either 930 or 911 rear hubs(911 needs to discard the splash plates) and parking brakes. For a caliper the best is the 964T rear. There are 2 successful methods of modifing these calipers for use on a 911. VCI does it one way(complicated IMO) and Power Haus does it a simpler way. Both work well w/ the 930 rotors. Here is a pic of the Power Haus mod on my car


The only other caveat is that 17" or better wheels must be used. Your stock 930 m/c is fine, no p/v is used either.