docwyte

Just as a plain jane bolt on with perhaps different caliper carriers? If so, which ones and what all do I need? My street wheels are 18" 993 wheels and track wheels are 17" boxster wheels, so that's my determining factor...

wjk_glynn

The larger front rotors from a 928 GTS or 964T-3.6 will slide right on without any adapters. Rotors from the 993TT will (I believe) require adapter-hats to get the correct offset.

But if you install any of those larger rotors, you'll also need to change the front calipers to match. You can use calipers from the 928 GTS (Big-Blacks) or 964T-3.6/993TT (Big Reds). And because you have a 951S, you don't have to buy caliper-adapters to fit those larger calipers.

A rough budget to buy all those parts new is $1K.

Karl.

martijn 944

Yes 964T-3.6, whit adaptors.

wjk_glynn

Hi martijn,

That looks like a spindle from a 951S, so the caliper should just mount directly. However, I see what looks like a bracket between the caliper and the spindle brake mounts. Why is it there?

Thanks.

Karl.

IPSC

How much bigger would the 928 GTS brakes be over the stock 951 S brakes? Which I believe are 928 S4 brakes?

IPSC

wjk_glynn

The standard 951 has rotors sizes of: Front = 298 x 28-mm; Rear = 299 x 24-mm

The 951S has the larger front rotors from the 928S4 which are 304 x 32-mm

THe 928 GTS and 964T-3.6/993TT have front rotors sized 322 x 32-mm

Karl.

Sam Lin

Karl, that spacer is what the original post is asking about I think - you can radially space the caliper to run a larger diameter rotor. The caliper curvature then doesn't match the rotor's outer radius, but as long as the change isn't great, you can do it and still retain full pad sweep.

Sam

IPSC

So which is more important? larger rotor or larger caliper in the choices presented here?

IPSC

docwyte

I want a larger rotor to have a bigger heat sink at the track. I think the clamping force of my current 951S/928S4 calipers is plenty...

wjk_glynn

What you say sounds reasonable. I'd just never heard anyone do it before...

IPSC

I agree that the calipers are good. I am going to get my rotors slotted in an attempt to manage heat along with some home brew brake ductting.

IPSC

Olli Snellman

How about these GT2 calipers & rotors:




Me and my friend Pete have these under our 951's.It's easier to put those to 951 spindle

Tom Pultz

If you have enough braking capacity now maybe all you need is better cooling. The cooling scoops on the 968 are supposed to work better. Another option might be the 968 M030 front rotors, which are the same size as yours but with ventilation holes. They are unfortuantely, very expensive... much more than the 911 3.6 rotors, which is what I have on my S2.