Question on 304x32 rotor upgrade...

stevemfr · 06-23-2009, 08:59 AM

...and yes, I have searched and read tons of brake upgrade threads without finding an answer.

I'm exploring various possibilities for front rotors for my brake upgrade. I've got 993 calipers (44/36and 34/30) and as I've got 16" wheels, would like to go with 304x32 rotors for the front and the turbo 309x28 rears (starting point is a 76 911 going turbo-wide and getting a 3.6 for the 'bahn as well as historic racing/hillclimbs).

As has been outlined in many posts (thanks Bill V.), the best method is the 993 2 piece rotors w/custom flat hats - but as I'm exceeding my budget on just about everything I'm doing to the car, I wanted to see if I could save money here. Goran (BeepBeep) outlined using 322mm 965 rotors over slightly turned down hubs, and I believe I remember reading in another post that someone else was using 298mm 964 rotors in a similar fashion - so the question: are the 993 rotors substantially different than the 964's? The 993 had 1 piece 304x32's. Is the overall height of the rotor (disc to mounting flange) different to the 964's?

Here are 2 of Goran's pics w/ 322mm rotors:

stevemfr · 11:22 PM

Wow, after reading through like a gazillion brake upgrade threads, I decide to post this question and - wouldn't you know it - the next couple of threads I look at has exactly the answer I'm looking for. Apparently this combination does work.

My 993 big brake upgrade on the SC

Does anyone else have any experience with a setup such as this or Instant-G's custom hubs? Jeff (Slider) mentioned in the thread above that his wheels were actually spaced somewhat further in with the new hubs despite the additional thickness of the rotor mounting surface between the hub and the wheel. This won't really matter much to me as far as tires rubbing goes because I'm going turbo-wide and can play with my spacing - it will space the rotors further out too though, which is something I'll have to take into account with my caliper adapters. Anyone have any words of wisdom?

Bill Verburg · Bill Verburg's Garage

as long as you are using 930 fenders, just use '81 up 930 hubs and rotors. It's all a bolt on.

for narrow fender cars you need to use one of the other solutions, best of course is the oem '78-80 304x32 w/ flat hats and stock hubs.

993 front uses a 1 piece 304x32 like the '81 up 930, some have installed them over the stock hubs, I have no experience w/ this

993tt/RS uses a larger 322x32 2 piece that can be easily adapted to 911 fronts w/ a flat hat, but in general you would want 17 or 18 for wheels w/ it.

stevemfr · 06-24-2009, 06:03 AM

Thanks Bill. Actually I was considering going this way just for the savings. The only used turbo hubs I could find locally up to now would set me back an additional €700.- Turning stock hubs down would cost me nothing. 993 rotors are also €50.- less a pair. I can swap to 930 items when I need new rotors. Hopefully by then I'll have recovered financially and be able to find some hubs at a decent price.

I'm pinching pennies, I know. The past 8 months have been atrocious business-wise, though. And, as I said, I'm already over my budget on every count: body, suspension, interior, and above all the motor.