dizzyj

I have big black calipers on my 944. I'm looking to get new rotors and im confused if late 928 rotors are the same as 928 gts rotors. can someone point me to an example of exactly what rotor I need? is there an oem part number I can reference?

thanks

samluke

I have a pair of virtually brand new 965 rotors. Great upgrade for big blacks. With spacers it puts the caliper on a larger braking radius.

Oem Porsche, with Porsche part numbers

dizzyj

sounds great sam. Ill pm ya. I have the m030 spindles, so I think 965 rotors are a direct replacement?

jtsporsche

What shall you do with your current brakes?

samluke

Yep, they are bolt on and you can use the big blacks with spacers or big reds. Send me your email and I will send pics. samluke@sbcglobal.net

lart951

why would he need spacers? if he has the turbo spindles and hubs nothing else is needed just the rotors and calipers

TonyG

Big black calipers are the same as Big Red calipers. The only difference is the color and the side the brake fluid jumper line is installed on (top or bottom).

Both calipers can be used without adapters as a direct bolt on when using M030 steering knuckles/spindles and with 965 (C2 turbo) rotors.

993TT rotors can be used with custom hats when using M030 steering knuckles without caliper adapters.

Then there's the mix up of other options:

993TT rotors with stock hats and non-M030 spindles using caliper adapters and big reds

965 rotors with non-M030 spindles using caliper adapters and big reds



TonyG

95ONE

Good info Tony. Hoping for updates on the new car!

samluke

When I was referring to big blacks I was referring to the stock 944 TurboS/928S4 calipers. U can't use 944 TurboS calipers on 965 rotors without spacing (been there done that). Sure you can direct bolt on big reds, or the true big blacks, as they are machined different. I never meant to infer you couldn't.

I assumed he was running 944 TurboS rotors and calipers. TurboS rotors are 304mmOD. 965 are 322MM OD or an additional 9mm on radius. By all means try and bolt on a 944TurboS caliper to a 965 rotor and see if you can get it to work. Plus why would you put the caliper back in the same position as before with a rotor of larger diameter?

965 is a low cost option on a TurboS without changing anything else out.

dizzyj

so let me see if I can summarize:
Big Red/Black can bet used with:
m030 spindles as is
non m030 spindles with adapters

once you go with Big red/black, regardless of m030 or not you have this for rotor selection:
928 gts rotors (322mm solid)
965 rotors (322mm drilled)
993t rotors with different hats (from lindsay, etc) (322mm drilled)

if you want slotted rotors, then you need to get 928 gts rotors, and have them slotted.

Sound right?

TonyG

... when you either use a 965 rotor or a 993TT rotor with a custom hat... both with M030 hubs

... and depending on the adapter you can use either the 965 rotor, a custom hat or stock hat 993TT rotor, and depending on the adapter you can use either the M030 hub or the non-M030 hubs.

Correct.

TonyG

Sound right?[/QUOTE]

TonyG

He doesn't. Based on the picture....

If he has M030 spindles & hubs, then the Big Red will bolt right on with a 965 front rotor (or 993TT rotor with a custom hat).

TonyG

dizzyj

so next question. For track use, which rotor? I would think:
a) any cheap ones you can find
b) 928gts solid (or have them slotted)

Whats the benefit to 993tt rotors?

I already have bb's, but my rotors are nearing out of spec. plus they are drilled, and I've heard worry some things about drilled rotors on the track.

TonyG

It depends on how fast the car is, how heavy the car is, and how hard you brakes... with respect to rotor sizing.

As far as a choice of rotors between 965 and 993TT on a race car... The 993TT rotor with an aluminum hat. This would provide the lowest unsprung weight out of the bunch.

TonyG

dizzyj

well, its for the car in my avatar. say 2600 lbs with me in it. call it 350hp, have not dynoed it, but im running a k27/8 at 14psi (23 when I go e85). I plan on getting into club racing, so I have been working on my threshold braking. Although truth be told, im sure compared to someone who actually knows what they are doing, im quite slow.

The main issue im trying to solve is that my brakes seem to have "pad knockback". i.e sometimes I get a soft pedal and catches very late. seems to do it after hard corners. I've bleed and re-bleed the brakes. Replacing the rotors/pads was the next step to diagnosing the cause. Any my rotors are getting pretty worn, so it lead to all these questions. If im going to buy new parts, I might as well know what im buying.