I bought S4 brake calipers front and rear to do a big brake conversion on my '78.

I bought the adapters from 928 Intl. that are needed for the front.

I then bought the front rotors from 928sRus.

The rotors are part #'s 993.351.045.10 & 993.351.046.10 cast hole rotors.

Now that the adapters and rotors are installed, I can see that either the rotors are too big in diameter or the adapters are not thick enough. The rotors measure 12.75" ( roughly 324mm ).

What is wrong here? There is about 3/4" of space between the mounting surface of the caliper and the adapter and the caliper is bottomed out on the rotor. The calipers have some casting #'s on them. They are 20.4564.00 & 20.4565.00

HELP!!!!

 

I will take the rotors, and send you the right ones

But seriously the rotors you have are too big in diameter for S4 upgrade.

 

Shawn I hink you may have GTS rotors and S4 calipers? I will help.

 

Those are listed as an option on 928 Specialists site.

What is the correct diameter?

 

322mm is the diameter of the GTS rotors iirc. But a search will reveal all.

 

993tt rotors not usable on any 928 except early cars with gts calipers

 

ry your s4 rotors Shawn

 

Thanks for the call Heinrich. It was great to talk to you. I'll try the S-4 rotors. Mark Kiborts mod may allow me to use these blingy rotors after all but I would make a whole new adapter instead of using two adapters stacked one on top of the other. We'll see. S4 rotors first. I've gotta get this car on the road.

 

THe 350mm rotors are bigger than GTS

 

grind the "ends" on the calipers to clear the rotor dia., get S4 rotors or GTS calipers.

 

Shawn,

Too funny, Calipers from ????, Brake adapters from 928 Int, Rotors from 928sRus and part numbers from 928 Specialists.... and you are seriously wondering why nothing fits together :-)

 

Hey man of many Sigs.....
Your new one has just arrived....


That is classic David...
You've singlehandedly destroyed at least two keyboards today


Shawn - I have some used rotors if you need them.....

 

You know, I was thinking the same thing as I was typing it.

I tried to buy the stainless brake hoses from you the other day but you don't carry them. These parts have ben collected over a period of a couple of years. I hope theres no hard feelings. I try to spread the love around.

 

Sorry for the confusion Colin. My original post said 350mm but I had plugged an extra inch into my metric calculator. Whoops! I have corrected it.

 

Fabio,
I just completed the same on my 78. I used calipers off an 88 S4, Big brake Adapters, and 993 rotors from Roger.
I hate to admit this in public, but when I first put them all together, they did not line up. I had put the big brake adapters on the spindles backwards. It took me awhile to figure it out.

edit: (add) The S4 rotors off of the same parts car as the calipers will not work on 78 hubs. When the rotors screws were tightened down, the rotor contacted the lower ball joint.