how do you tell the diff between a 951 rear caliper and a 965 rear caliper

[Erik Mckenna]

I have a set of what look like 951 calipers I picked up at Hershey last year... I am going to be putting them on the rear of my SC I have a set of 993 C4 silver calipers for the front.. I am trying to figure out what I have for the rear so that I can figure out what rotor size to get and IF what I have are even 951 calipers. If the are not then I am trying to find out what I have... I am thinking that they are the same as a 965 or even a 993 caliper as far as mod's to have them mounted on the SC but I am sure I am wrong.
SO.. do you guys know where and what I can look for to figure iut what I have so that I may ask the right questioons to BILL V. hhaha later concerning the right set i'll need to get this swap over done.
so I guess I really need to know how do I tell the calipers from one another..
should I measure piston size or is it something else.. I simply need to know what I have as far as the rear goes so I can start to buy what I need to complete this project..
TIA!
THanks...

[North Coast Cab]

Eric,
The 965 rear has 34/30 pistons where the 951 has 30/28. I believe the 965 has a throat wide enough for the 930 sized rotor. The 951 rears have to have the throats opened up, mounting holes filled and redrilled. The 965 are the best choice, but they are very hard to find and very expensive. Either way the 930 OEM 28mm rear rotor is the best option for your car.

John

[Erik Mckenna]

I'll go out and measure.... see what I have...

Thanks John...If they are the 951's I remember seeing a thread where someone ground some material away to alloy for the 930 stock rotors...

[Bill Verburg]

There are 2 different small brembo calipers w/ 30/34 pistons

*the 993 rears will have a pad box width of 63.5mm, 944/951/968/964 rear will all have the same pad box width but smaller 28/30 pistons

*the 965 rears will have a pad box width of 67.5mm

They all have pad boxes ~98mm long

[martin_gibson]

Bill,

Will a 965 rear caliper fit behind an 8" x 16" 911 fuch and still be contained within the standard rear SC flare or will 951 x 8" (or 9" fuchs) be required?

Thx

Martin Gibson
83 911SC 3.6

[Bill Verburg]

Originally posted by martin_gibson
Bill,

Will a 965 rear caliper fit behind an 8" x 16" 911 fuch and still be contained within the standard rear SC flare or will 951 x 8" (or 9" fuchs) be required?

Thx

Martin Gibson
83 911SC 3.6

Dunno, never tried it, a 9 has a lot of room. The rear rotor has a pretty big o/s that gives you a lot of extra room so in the back a 8" +10.6 ET would probably clear.