A930Rocket

Did a search with no results.

What's the difference between the two?

I know the Big Reds have more pad area, but how much?

Number and size of pistons?

Rotors diferences? Diameter and width?

Is it an upgrade from stock 930 brakes to 928 S4's? How much?

TIA

Jim

Brent 930

Jim, this is what I have heard...it is an upgrade but there not as good as the big reds. I think you need an adaptor plate but can use your stock 930 rotors and 16" wheels will still fit. I'm sure someone who uses them can tell you more. It's an upgrade I would consider for the front and move the stock ones to the back.

A930Rocket

Brent,

One concern I had was having too much brake caliper/pad and not enough rotor mass. My current rotors already don't last long enough with the stock brakes.

You have the same idea I had about installing them on the front and moving my fronts to the rear.

There's an eBay sale for a pair now, including adapters, lines. If the price was right, maybe it's worth it?

Steve Weiner-Rennsport Systems

Hi Jim:

Big Red (TT) use a larger (about 30%) pad and have 4 larger pistons than the S4 calipers.

They are significantly bigger,..

S4 calipers are made for rotors in the 295-322mm range and 26-32mm thick. Big Red's use 322mm diameter rotors that are 32mm(F) and 28mm(R) thick.

S4 Calipers fit inside 16" wheels; Big Red's need 17" or larger.

For track use, you cannot beat Big Red's on the 930.

A relatively simple brake upgrade for a Turbo would be to install S4 front calipers and 322mm rotors (they need adapters) and move the front Turbo calipers to the rear (using rear caliper bridges).

It really depends on what you do and how you use your car, though.

A930Rocket

Hi Steve,

I use my car on the track, which is not but 5-6 times a year. The car is driven hard at the track. The rest is street time, which is not near enough.

The only reason I even thought about these was the aBay auction. What would they worth with adapters, etc? $400 or so?

Would they be too much for the stock rotors?

Big Reds are a Big Step money wise, so I'm not sure if I can justify that much.

Jim

Steve Weiner-Rennsport Systems

Hi Jim:

I do not know if they are worth $400 without seeing them first hand,... They might need seals, have rounded off bleeders, dented cross pipes, etc.

If you do such a thing, you really should install larger front rotors to avoid overtemping those stock 305mm Turbo front ones you currently have.

Whether or not you need Big Red's depends on how your stock brakes are holding on the track.

biiig-hp

Jim, I used the same set up for 3 years (S4 calipers on stock rotors, factory fronts on the rear) and loved it. I use to have a problem with brake fade and boiling my brake fluid till I made the change. Reason is your not on the brakes as long so you don't create heat. For the past 4 years I've been running big reds, they are better but if the price is right go for the S4 upgrade.

Dknebes

Jim,

I just upgraded to 993 Big Reds with 13" rotors, rebuilt and powder coated my front brakes and moved to rear instaled new rotors in the rear and used Castrol SRF fluid. Also instaled Coil overs front and rear. I am having problems with to much negative camber in the rear but will solve that in time. Good luck with your project.

David 89 930 700hp

Lomotpk

4 what its worth I could NOT get Stock 930 16" Fuchs on my S4 front calipers. The calipers were too big by about 1-2 mm. Gouged little dents into the inside of the rim when we tightened then down.

A930Rocket

I heard it took a modular 16" wheel to clear. For the track, I have 18" BBS wheels. For the street, 16" Fuchs. I guess I would have to add 17" wheels to the price....

Geoffrey

I have fit 993TT Big reds under 16" BBS racing wheels.

I will say that brake cooling goes a long way to make the stock brakes work very, very well. I changed to Big Reds because I was going through pads too quickly.

There is one disadvantage of the big red upgrade that isn't discussed much and that is pedal feel. Because of the larger pistons and the need to push more fluid the pedal feel is nowhere near as firm or as nice as the stock setup.

A930Rocket

I already have brake ducting off my air dam to the rotor hats. A definate help.

I use up pads every 2 events (PFC 90's) at $125

What would one use for track pads with the 928 calipers and what would the cost be? Stock, PFC's, etc.?

Peter Carroll/Toronto

I've already got S4s up front and C2s on the rear using the stock rotors. I suspect I have enough pad. What exactly are the bigger rotors? Since my rotors are shot anyway, that sounds like the ticket. Can someone please advise part numbers and a source?

Do I need new mounting brackets to move the caliper out for the larger rotor? I'm using 17" rims so I'm not so concerned with clearance.

If I did 993TT calipers and larger rotors do I need 18" rims?

BTW: I had filed 1-2mm off the corners of the S4s and then the fit the stock Fuches perfectly. A little paint and you'll never know the difference. There was so little material removed there is no need to worry about weakening them.

Peter
http://www.pcaucr.org/pcaucr/forum/post.jsp?postid=1803

A930Rocket

I think you do need the 18's.

I had to remove a small amount as well to clear the Fuchs.

Now if I could just figure out how to get the new dust seals in, I'll be in great shape. Until then, they are sitting on my work bench.