Convert 993TT calipers into 993RS

[mmasse]

Does anyone knows where to get brake caliper pistons for a rear 993RS?

I tried the dealer, but it seems that the part numbers on PET are for the repair kit which only includes the seals. There seems to be no part number for the piston itself.

After some time of unsuccessfuly looking after a set of 993RS calipers to replace my rear 993TT, I have decided to convert mine to RS.
Bill V. told me that the only difference between these two calipers are the piston sizes. The 993TT pistons are 28/28, while the 993RS are 36/30.



It will be of great help if any one has a pic of a disassembled 993 caliper (either TT or RS) would be fine. I just want to check if there are any grooves on the piston housing.

Bill, some time agoo you mentioned that a friend of your was working on a similar idea. Did you finally did it?

Thanks

[Flieger]

So you have to machine the piston bores?

Personally, I would be nervous about small stress risers/cracks from machining if the brakes will see high temps and track use.

just my opinion...

[Bill Verburg]

all repair kits consist of 1 piston, 1 inner seal, 1 outer seal
36mm 951.351.919.10
34mm 965.352.919.10
30mm 951.352.919.11

You are aware that using the 993Rs or 993tt rear caliper on a 911 is no where near as straight forward as using a 965 or 993 rear?

1) to use the 322x28 rotor the parking brakes needs to be eliminated or modified
2) the caliper needs to be converted to radial mount

haven't heard on the progress in adapting bigger pistons

[mmasse]

Thanks for your replies.

Anyone else have any thoughts on Fliegers comment. Would that be an issue? Havent the bore been machine at the time of manufacture? I would not like to do this if there is any potential problem as the one suggested by Flieger.

Bill, I already have the 993TT installed on my car. The problem is that the 993TT pistons are two small for my setup with Brembo F40 on the front. I have too much front bias.


Thanks

[Flieger]

Just to make sure I understand what you are talking about...

You want to put 36/30 993RS pistons into your 28/28 993TT bores?

I would think that the bore would need to be expanded to make the bigger piston work.

[pete911]

You can get the entire caliper new from Porsche, and probably right here from Pelican. The part numbers are:

993 352 425 80 For the left rear
993 352 426 80 For the right rear

I bought a set last year.

Pete