Wait a sec - piston size : pedal travel

- does this mean that when I upgrade the front of my '86 951 to S4 brakes next weekend, I will need to change master cylinders as well?!

What rear prop valve will I need?

 

Hmm...I don't know the specifics on whether S4 calipers can accomodate bigger rotors but I've driven a 951 with S4 brakes and one with BR's and I really have to say the BR's were head and shoulders above the S4 brakes. The kind of braking power that makes you wonder if the 5 point harness will keep you from going thru the windshield.

To address Keith's question, the BR's using the stock master cylinder were definitely spongier than with stock calipers but nothing that I couldn't live with.

I think Danno has a really good point about looking to non-porsche solutions as well to find great value. The cheapest I've seen the BR kits is just under $1200 and I'd love to see what that would buy from a different manufacturer.

-Hugh
'86 951 black/linen/baby brembos

 

In Robby's case, I don't think BR calipers would give you much over the standard TurboS S4 callipers. What would really make a difference is adding that 0.75" larger rotor for additional leverage when going to full 13" rotors.

Similar thing when upgrading non-S brakes. For the price of TurboS parts, you might as well just get the full 13" brake upgrade with BR calipers.

From the looks of them, the monoblock-style Boxster calipers may have less of a clearance issue on 16" wheels and 13" rotors.

 

Yeah- Monoblocks w/HUGE ceramic rotors!!! That's what I'm thinking... I'm going to call around a few places tommorrow to try to find out about clearance and such for larger rotors for my 16" rims, but I don't expect much- I'll be asking about ceramics too. I'll repost if I find anything cool.

As for BR's feeling stronger than the S4's- many people say this, but are usually using larger rotors (12 5/8" - 13") b/c they come w/the packages, and they use 17" rims. I agree Danno, that the extra leverage is the bigger of the two differences.

As for S4's being able to use the largest of rotors in the end, and/or actually being better than BR's- I'm not sure at all- that's just what KVR and one or two other places say. One other thing I forgot to mention about that, is that they say the taller pad on the BR actually makes it flex more under heavy braking(?). You guy's should really take a look at the links I posted earlier in this thread- that stuff is direct info from places that offer kits for Mitsu 3000GT's- those cars are about 3800lbs! The places are all offering Porshe/Brembo brakes, and there are some cool sections on specs in some of those links...

 

ok, so then, was there a different master cylinder on the Turbo S?

Also, is there a more economical alternative to the factory Turbo S rotors that can be used on an 89 951? (for future reference)

 

kieth,

I think there were two different master cylnders, but it was not because of the Turbo S's brakes, but because of the anti-lock braking system, all 944 with anti-lock had a different master than the ones with out. Or at least is how I remember it, I asked the same thing wondering if I had to upgrade to power the Big Reds I want to get, and I was told that the original master in my car would do just fine.

 

right on, thanks. I will be changing this stuff over next weekend, then!

 

Keith,

I'm sorry, I meant to respond to your master cyl question im my last response... One of the links I left on one of my first responses in this post, somehow led me to a page that had some info on that kind of stuff. It showed different rotor sizes for all of the 911's throughout their lifespan- diameter, thickness, etc. There was another section on master cylinder sizes, and it showed that the MC would have to be changed only if a certain limit had been surpassed. There is an acceptable range, where a MC would work for various piston size, etc, but eventually, you would have such an increase, that you would have to upgrade the MC, as pedal travel would become so great as to be unacceptable. Unfortunately, I'm not aware of the MC sizes for the 944 series, but I would assume that the NA 944's would be different from the 951's at least. At any rate, someone on the one of those links, talked about replacing the MC when doing an upgrade b/c of travel, and b/c the person liked it very short- I don't believe it was a Porsche in question, as one of those sites is for Mitsubishi brake upgrades- again, the reason I enclosed it is b/c it has some interesting info, prices, etc, and the upgrades in question are Porsche/Brembo. Many other cars use these as well- I've seen several BMW sites for instance, that use Porsche/Brembo brake upgrades...

 

Robby - I'll check them out - thanks!

 

Finally installed the 968 calipers on my 951. all seems to be well so far. thanks to you all for your help!

sm

 

Old thread bump. Trying to find information on whether late-offset Turbo calipers (non-S) will directly bolt-on to an '86 Turbo (early offset.)

Looks like it does based on the content in this thread but am hoping for solid confirmation.

The OP hasn't posted since 2009, but his user page shows he logged in 6 days ago so hoping he (or someone else with knowledge) can confirm.

 

I think this thread: https://rennlist.com/forums/944-turb...fferences.html

...confirms that you can bolt up non-M030 late offset calipers on an '86 without needing any other hardware changes (rotors, spindles, etc.)

Would be cool if someone else can also post up here with solid confirmation.

 

Calipers all are interchangeable regardless of offset.