I read somewhere with the base front caliper in rear of an S model you stand the chance of locking up the rear brake first. Is this even possible? I always thought the fronts did most of the work and the brake bias is set that way. I also heard both the s and base use the same size staggered pistons.

If you want bigger front discs there is a guy on the UK boxa.net forum that has had some made up with a spacer kit to work with the existing S caliper. The cost premium over an OE disc is negligible.

The front disc rotors and calipers are a simple bolt on and go upgrade on a base 986. No changes to the brake bias or master cylinder is required. The rears are another story as they require major surgery to install.

Hey Edc,
I did a search over there but didn't find anything. I ordered the spacers from girodisc so looks like the front is going to happen. Thanks for the link.

Thanks JFP,
I was hoping the rear conversion would be easier. Unfortunately I have to do that base to S rear brake conversion. There's a chance I might be able to get the Carrera S rotor to fit the S setup. The girodisc rear setup only fits on the S model, so base owners will have to do the swap if they want bigger rear rotors. I'm going to do a DIY for the readers here since there seems to be no threads on the rear conversion. I couldn't find any info on the rear conversions anywhere, google search and all. If anyone has any info on a rear brake conversions please post link here.

Here are some REAR disc pics. Aftermarket base, S model and a Carrera S 330mm:

http://i5.photobucket.com/albums/y15...pshlzhdxwj.jpg

There's about a 1/2" difference in the rear ID where the parking brake pads grip against the inner rear wall. The 911 S rotor bolts on both the base and S model.

http://i5.photobucket.com/albums/y15...psh6wqkhf6.jpg

The Carrera rotor doesn't fit flush on either base or S. Its close but about an 1/8 gap. There is something keeping it from sitting on the face. My guess is the rear lip which I can cut out on a lathe.

Since I had both the base and S rears taken apart, I tried fitting the rear base rotor on the S. It doesn't fit. The S has a wider handbrake setup.

Ok next step is to find any info on the base to S rear conversion. Need parts and info for the DIY writeup.

Because the S cars use different axles and carrier hubs, they also carry the e-brake from the larger cars, which as you observed are larger in diameter. In order to convert the rear of a base Boxster to the S brake set up in a bolt on manner (no weird or unobtainable adaptors), you need the carriers, hubs, and e-brakes off an S car.

Got my mounting kit from girodisc. 5 bucks per bolt and spacer. Whole kit was 80. I figure the bolts are just 911 bolts. I will make my own kit for now on. I was hoping for a one piece spacer. I could have spun my own spacer on a lathe but don't have a mill to make a one piece spacer.

http://i5.photobucket.com/albums/y15...psrwngjqeb.jpg

http://i5.photobucket.com/albums/y15...pswg6syjje.jpg

On Boxa.net find user Patt. I think it's a bigger disc with a caliper spacer.

This thread has me thinking about doing my own big brake upgrade. I'm thinking 17z Brembos with 355mm rotors.

That would be awesome Woody. I found rotors for about 230 each.
The spacers are five bucks each. I'm more then sure the pins can be pressed in instead of being cut. That's a big brake kit for under 500.