About time too as my Carrera brake pads were down to the metal.

The idea was simple, get rid of the Carrera Calipers and mount Boxster Calipers all around using the mounting adapters from Rich Johnson.


Of course, nothing ever goes as planned:

First, i failed to read Rich's instructions that clearly state that you have to use a 20mm 911 SC rear rotor.

Well, i have 24mm Carrera rear rotors. The Boxster Calipers had to be machined (2mm off each of the brake pad pins) and the adapters had to be milled to center the Boxster Calipers over the wider rotors.


Then, after everything was bolted together, i recalled reading that the hard brake lines may not be long enough.
And sure enough (of course) the front brake lines were about 1" too short. Arrghhh.


McMark came to the rescue and we made two new lines.

In the rear, i used banjo fittings on the Calipers (Thanks to Eric Shea for those!) and the rear brakelines were no problem.

Mark and i then bled the brakes. I was still getting some air in the front, but it was already 9pm so we decided to call it a night and i drove it home (40+ miles). The brakes actually felt fine, they seem to work great.
I'll go back to the OC shop next weekend and we'll bleed them again.



And now for the pitchers:

RJ Adapters:

Test fit in the rear:

Sharpie marks for milling the adapters so they would center over the 24mm rear rotors:

Milled down rear adapter mounted:

Rear Caliper bolted up:

The inner rear pads need to be shaved down a bit as they would otherwise hit the mounting ears (shaved one on the left):

Fuzzy pic of the retaining pin that i cut down to 78mm length. Otherwise it's too long to completely move out of the way to replace the rear brake pads:

Everything in place. I added some blue loctite to the mounting bolts for the final assembly:

One more, rear all installed:

The front went on much easier. Here's the adapter mounted:

Test fitting the front:

And final assembly:

Time for a shower and some beer!

Wow that should give you some serious stopping power. Sweet.

Those look fantastic!!!!!!!!!

Jack

Wow, long day, glad to hear you got it done. Looks great.

Jeff

Nice work. Damn those are big.

Lookin' way good!!!!!!

I have Carrera calipers too. A Wilwood conversion is a little more complicated since a 90 degree adapter isn't in the cards. Since I have a couple of those left over after replacing my fronts with differential billets, I think I'll stick with them... dangit. I already have the SC and Carrera rotors but figured the SC hats weighed a little less. I know... splitting hairs.

Nice work!

Please post your feedback after your road test. I saw a few guys try Boxster S brakes on an early 911 ('69) HSR car. They had a problem with lock up under threashold braking. I've always thought the Boxster calipers would be great for a 6 conversion.

Andy,

Which Boxster caliper did you install. Actually, I don't know anything about Boxster calipers; are standard different than "S" ?
Thanks,
Andys

I have had Boxster calipers on my six for about 3 years now. Love them. No lockup, and it stops with NO fading at all.

They are big! But they are actually *lighter* than the Carrera calipers i took off ...

And light is gud.

These are standard Boxster calipers.

If i'm not mistaken, the "S" calipers are different and won't work with the RJ adapters.

Andy,

Forgot to ask: What master cylinder diameter are you using with this setup?

Andys

19mm

Very cool. 914 that I drove with these on was really night and day different from my then 911s front with M rears. Your car must be a blast on the track and AX courses.

Finally upgraded my brakes like Andy had done. Was running Boxster front and Carerra rear. Using Rich Johnson's beautifully made adapter the task was uncomplicated and as Andy described, but simpler in my case as I went with the SC rotors (20 mm) vice the Carerra (24 mm). I had been running the 24 mm rotors but thought that I'd give the 20 mm ones a try and if I have heat/warping issues can always perform the rest of the mod later and go to 24 mm rotors.

My brake lines had enough room to thread into the caliper without a banjo like Andy used.

Looking forward to trying out this upgrade next month at my first event of the year at Buttonwillow.

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Andy - Great job and the brakes look great. What, if anything are you doing regarding brake bias? Do you intend to use your car on the track? With all that volume it will be interesting to see if you end up with a larger MC. I had a 19 and moved up to a 23/930. Food for thought and always a slippery slope...

Don't know what Andy is running for a M/C but I have a 23 mm and it was a very hard pedal with the Carerra/Carerra and Boxster/Carerra combo. I think that it will be very good and easy to modulate with the Boxster fr/rr combo.

I've been using a 23mm mc as well and it does give a hard pedal on my Boxster setup too. I think i'd like a little more leveraged feel with something in the 21mm range, but I would imagine the 19mm being a little more travel range than I'd be comfortable with. I am curious what pads people are using for the 914, given the lack of vacuum assist and generally cooler operating temps (in my case anyway).

Pagid Black - but it's a track only car.

FWIW, I use the Pagid Black as well with my Carrera calipers. Some of the 911 guys say they are too agressive but I have not found that the case with the 914 application.

I currently have the 19mm MC. I have to bleed the brakes again, so i can't comment on the pedal feel just yet. It did feel a bit soft after the first bleeding, but that was to be expected.

As for the bias, i have been running with a "T" for years and so far, it feels OK. The real test will be my next AX where i plan to really put the brakes to the test.
I'm hoping to get the fronts to lock up first but have enough bias to the rear to make them work hard.

We'll see how that pans out ...

Is there an emergency brake as part of this solution?

The 911 eBrake has nothing to do with the calipers. They're brake shoes inside the rotor.

Okieflyer wrote: "...but I would imagine the 19mm being a little more travel range than I'd be comfortable with."

Yeah, at 150+ into a downhill 90-degree corner... I like a HARD pedal, knowing the brakes are REALLY there. Auto-x is completely diferent...your "life" is not on the line.

Keep us posted as you are able to get some time with the brakes. Once again, it's an attractive set-up!

i have boxster S calipers too.

i would love to do this to my 914 too, the boxster is 50% heavier than the teener and stops on a dime- this is going to be great on the track with your teener!

i dont have a track car, so would be overkill i think for my 2.0, but maybe the
BMW upgrade might be worth it? what do you advise- i am on a 4 lug ...

I too have boxsters on my 914...

Question for you peeps...
did you orient the rear calipers so the larger piston was the leading piston? (i.e. LR becomes RR, and RR becomes LR, and you have to flip the bleeders to the top, and the x-over to the bottom).

Or did you just bolt them on, and let the smaller piston lead?

(I see a mix of the above on this thread)

I flipped the oil feed lines so they are the same as the Boxster. I think the small piston is on top. Can't remember but I made sure it was the same as the Boxster. I am also running a 19mm master cylinder and I am quite happy with it for street and autocross.

Just bolted them on and ignored the pistons. Mounted so the bleeders are on top.

I doubt it will make any noticeable difference ...

I would tend to believe that also.. but the fronts use the larger piston as the leading piston (or so i thought?)
did a little digging on the reason for stepped/differential caliper bores. Sounds like bolt them on and go!

Differential bore calipers -- As the surface of the rotor heats up, the clamping force of the pistons has to be increased to avoid brake fade. If the caliper has multiple pistons (or multiple pairs of pistons), the brake rotor surface is initially heated by the pistons pushing against the brake pad at the leading edge of the caliper, making the rotor surface hotter when it rotates back to the pistons closer to the trailing edge of the caliper. Therefore it helps if the pistons closer to the rear edge of the caliper are larger. Differential-bore calipers use smaller pistons up front, larger pistons toward the back

In that case it seems the way i mounted mine is correct?

On the rear, the smaller piston is on top. I have to check on the fronts.

Yep..sounds like you were right. bolt on and go!

For your stock-ish car there is more benefit to getting your factory equipment brakes
rebuilt to tip top shape. Less weight, designed balance, and can be less cost.
I used the 911 parking brake setup from Tangerine Racing and it is effective.
All these "upgrades" add more mass, and depending on the use, may not make your competition times any faster. ymmv.

The Boxster calipers are *light*. They are most certainly much lighter than the (smaller) Carrera calipers they replaced.

They might even be lighter than the stock 914/4 calipers.

pretty sure they're lighter than the front M-calipers i replaced them with...

The rear is a toss up. Heavier rotor (vented), and 911 ebrake hardware to make up for the lack of integrate p-brake.

Just after reading the Boxster caliper update thread, I came across a pair of adapters to mount the Boxster front calipers on the stock 914 spindle ( 3" )

Wondering if anyone else has made this conversion. I'm probably not gonna do it at this point and will be listing in the classifieds shortly

I've never seen 3" M struts to Boxster adapters. They all are 3.5" A/S caliper struts.

We (craig downs and I) had to mill 3" struts and make custom adapters to fit....
http://www.914world.com/bbs2/index.php?sho...=77197&st=0


Where did you find those Jim?

I remember the thread where you and Craig did that. The adapters were made by Mark--the machinist that made the billet hubs for Brad. Bought them from Mark at the G & Rswapmeet