Help on Boxster brake upgrade for 80`s SC.

[911-lightning]

Hey,

I am thinking about doing an Boxster brake upgrade on my 1980 SC. I have a few questions before I proceed with the purchase of parts. Should I use the Boxster calipers front and rear? I see that others use Boxster calipers in front and Carrera calipers at the rear.

Have someone done this upgrade before? Some good tips maybe?
I see that it is possible to buy a kit for use of Boxster caliper here on Pelican Parts.

Pelican Parts.com - Boxster Brake Kit

Anyone know if this kit is for both front and rear? Or just a front?

[James Brown]

looks like the only thing you get in the kit is the adapter blocks, you need everything else

[puffinator]

TRE sells a complete kit. I had installed on an 85 Carrera and I am happy with the result.

[wildcat077]

You will need the adaptors from TRE and a 23mm master cylinder for the Boxster 986 calipers.You use the stock 911 Carrera rotors !
The Boxster "S" calipers will not work for this application.

Cheers !
Phil

[Joe Bob]

Rotors?

[911-lightning]

Originally Posted by wildcat077

You will need the adaptors from TRE and a 23mm master cylinder for the Boxster 986 calipers.You use the stock 911 Carrera rotors !
The Boxster "S" calipers will not work for this application.

Cheers !
Phil

So I need to change the cylinder? I got the impression that the stock SC cylinder would work with the Boxster calipers. Is this a straight forward change or does it require modifications?

Thx for the answers!

Fredrik

[GaryR]

Don't waste your money, stock brakes are more than adequate if in good condition..

[911-lightning]

Originally Posted by puffinator

TRE sells a complete kit. I had installed on an 85 Carrera and I am happy with the result.

I have had some nice mail correspondence with TRE Motorsports today

Very helpful and professional!

[michael lang]

911, is there something wrong with the braking that is currently on your car? I like the Boxster brake upgrade but after looking at the total amount it take I decided that the performance gains I would get did not in my mind justify the amount of money it would take to put them on. Especially since I only do DE's. I am not trying to discourage you from making your car the way you want it, I will second what Gary suggested, the stock brakes are more than adequate.

[Bill Verburg]

Here's a comparison of what you have w/ several different brake setups


the highlights

• Boxster front w/ SC M rear is way front biased
• Best bias comes from stock SC or Boxster front/wide A rear
• yes, you get a little more brake torque from Boxster fronts but brake torque is not a weakness of stock brakes
• the weakness of stock brakes is the thermal capacity of the rotors
• Boxster fronts put more heat into the same size rotors making heat problems worse
• you don't need a 23mm m/c w/ Boxster/M combinations or even w/ Box/Box combo but pedal feel will be way better w/ a 23.8mm m/c

[Rot 911]

Bill, nice write up and explanation. Never understood the need to do this swap. As you pointed out, cooling can be a problem, but really only on the track. Plenty of DIY brake cooling ideas already posted here on the board.

[IROC]

Bill - unless I'm missing something, there appear to be some inconsistencies in your spreadsheet above. For instance, all the rotors are shown as 20mm thick which is not the case, obviously.

Doesn't change the end result, of course, but I was wondering why all the pad were listed as the same size, etc...

[Bill Verburg]

Originally Posted by IROC

Bill - unless I'm missing something, there appear to be some inconsistencies in your spreadsheet above. For instance, all the rotors are shown as 20mm thick which is not the case, obviously.

Doesn't change the end result, of course, but I was wondering why all the pad were listed as the same size, etc...

Thanks, I'll go through and change those #s, there was a lot of cut and pasting going into it and I was mainly concerned w/ the brake torque aspect

[javadog]

While you're at it, what's the entry in the slave/master ratio column on each line labeled "rear"?

JR

[Bill Verburg]

Originally Posted by javadog

While you're at it, what's the entry in the slave/master ratio column on each line labeled "rear"?

JR

Not following you JR

[GaryR]

Brakes are for sissy's!

[Bill Verburg]

Originally Posted by GaryR

Brakes are for sissy's!

Says the macho man w/ a bent chassis

[GaryR]

Not sure I like that comment there Bill...

[Bill Verburg]

Originally Posted by GaryR

Not sure I like that comment there Bill...

It was meant in jest, my apologies

[Bill Verburg]

here' an amended version, as always if you see anything that needs work, let me know