If you have that oddball mis-matched (early clear and late dichromate) pair of S-Calipers, I'm looking. I have a customer who has such a pair and this would help make everything right in the world.

Early style are of the 908 casting and have a clear finish. Later styles have the 910 style nose and are greenish dichromate. Looking for just one of each.

Pics so you understand the differences:

Early:


Late:

I think I have some mis matched S calipers. I will see if I can dig them up this weekend when I get home for Texas. PM me with what they are worth to you.
Bruce

Bruce,

I think I found a trade but... I found a couple so, I may be able to put you in touch with the guy that has another mis-matched set. There are no rights or lefts with these so, you should be good to go.

I may need them as well. Touch base when you have some time.

Eric,

I noticed the the "late" style caliper has more material on it on the near side as oriented in your pictures. Do you think this to address the oft talked about 'flex' of the aluminum calipers? Did it work? Any other enhancement made that makes one style better than the other?

Also, out of curiosity, what year did they change from early to late?

I don't know. I don't buy into the flex crap. Seriously? These calipers "won" LeMans, Targa Florio, Nürburgring, Sebring, Road Atlanta... they literally won the first "World Cup" for Porsche and todays Internet Racers (our equivilant to an armchair quarterback) can't make a lap around Willow Springs without complaining about "flex"??

They even bolt on the uber-heavey A-Caliper and Wide A-Calipers (heaviest caliper "ever" made for a 911) as a "resolution"?

I think the floorboard flexes more than anything which is why I welded on Chris's crossbar brace:



I've had both styles back to back on my 911 and a ) didn't notice flex and b ) didn't notice a difference. I changed to the later style because my lifestyle (building calipers) afforded me the opportunity, and, my car is an RS tribute which should have the later style. My 914-6/GT project will be running the 908 style with an additional 3mm shaved off the tops to make them flex even more!



So... off soapbox but; I think you get my drift.

They switched in 1972.8-ish to the later style. It is marked by an "earlier" style nose that first showed up in the 910 calipers of 1966-67. If the caliper were to flex I would imagine the space above the rotor gap would be the culprit (imagine a clam shell opening and closing). That would blow out the theory that the nose was fortified for that reason but... never say never.

I have no personal experience switching between different calipers on the same car to be able to comment on whether the 'flex' is real or not. My conclusion from observation has been that it didn't exist, or at least not to a great degree, given the longevity of the design on Porsche's top of the line models and their use on their racing cars. But it was interesting to see in your pictures that the later model calipers had more material. Contrary to maintaining the light weight strategy if it didn't offer some performance improvement.

The difference is 4 ounces each (just happen to have empty core shells here side-by-side). Hard to say why it was done...

Hmmm. Not much weight to add, but added cost and weight none the less. We may never know why, but its interesting to ponder.