Right ON! I'm curious how he did it? Can you post a pic? Will they also work with 15" wheels?

Thanks Jim!

Her ya' go... I'm not sure the pic where the adapter is mounted is oriented correctly...

Like Andy stated, I know I saved weight up front coming from the Carrera Tank calipers up front, but the back end gained weight in my case. I like the modern calipers for several reasons and they are effective stoppers, but I can't say for sure that I have any more shear stopping power than any other P-car. It could be pad related for all I know, but my suby forester with it's vac assist can stop just as hard if not harder.

But then again it could be perception of modulation.

Wow, Jim.

Those look scary thin at the corners of the mounting hole. Interesting!

It's been 2 months now, Andy. How do you like them?

I was excited about them, but yeah, that's scary!

Aaron, what's your front setup?

They work great!

I love mine!! They work great and they don't squeak like the 944 Turbo brakes I had before.

Hey, I'm no engineer by any means, but these mounting brackets scare the hell out of me. Typically, you would see the 2 caliper thru bolts situated so that the bolts are seeing shear forces. These bolts do pretty well with this force, in excess of 5000lbs or so. Now you're putting these bolts in tensile mode, which seems somewhat shady. Every bolt i have seen on a caliper, has always been designed for shear. Is this the new trend by the automotive engineers? Moreover, this mounting bracket, is it comprised of aluminum? If so, are these thru bolts, with nuts on the back end?
Maybe I'm overthinking this, but I would like to hear some input from a Mechanical engineer.
In the mean time, you could cut a square hole in your floor boards and do some Flintstone braking as a last resort if the calipers snap off.

I have not mounted those adapters. They are in a drawer....

I have the same setup as Andy but I installed the early 911 e-brakes on the rear.
It wasn't too bad had to measure alot to get things just right with the lever mounts.
I also had to make a small cable to attach to the 914 e brake cable.
I took a look at my caliper pistons like Aaron brought up . The rear calipers bolt right up ( small piston to the top ) as for the fronts they need to be flipped ( right now larger piston is on top ) .

So here I go digging up an old thread, and digging into minutia.

I know that the calipers that start with 996 are newer than 986, but does anyone have an idea on the next three numbers?

Rich said to stay away from the .352. calipers but I can't for the life of me see a difference when I have them in my hand. I'm on the hunt for:

986/996.351.421
986/996.351.422
986/996.351.424
986/996.351.425

Everywhere I turn, I'm finding sets that have 1 or 2 .352. calipers in the mix. Can they really be that different?

I just checked my calipers and this is what I have for #'s.
Fronts are : 986 351 421 & 986 351 422
Rears are : 996 352 421 & 996 352 442

Why stay away from the .352 # ?

I have the standard Boxster calipers but there's also a Boxster S calipers which is different from what I hear.

I think you may have a set of fronts on the rear...

From the Pelican site.
http://www.pelicanparts.com/catalog/shopca..._BRKprf_pg1.htm

The part numbers for the Boxster calipers required for this kit:

Front left: 986-351-421-03
Front right: 986-351-422-03
Rear left: 986-352-423-01
Rear right: 986-352-424-01

The part numbers for the brake rotors required for this kit:

Front Carrera: 911-351-041-22
Rear 911SC: 901-352-041-14

The part numbers for the brake pads required for this kit:

Front: 986-351-939-15
Rear: 986-352-939-10

Yes- Those are the correct PN's for the calipers you should be using.

and pads

Hmmm...

I've got another set on the way. So I'll have to see what the part numbers are when they arrive. I KNOW the last set was wrong. (They shipped 3 rears and 1 front.)

Thanks gang.

Will the Boxster calipers fit under 15" Fuchs?

They should, i run them under 15" cookie cutters ...

Don't try to run one of the collapsible spares with the Boxster calipers. The offset is wrong and the caliper locks against the wheel (BTDT)

I bought a Boxster spare rim so I don't have to worry about it.

I got a full size 7" cookie cutter as a spare wheel, so no problems there.

Andy, can you pass on Rick Johnson's information, his adapters look so much "beefier" than the other adapters I've seen.

Better than what I've been trying to work out. If he's making sets, I'd be in for some.

Rob

You can find his contact info here:
http://www.914world.com/bbs2/index.php?showtopic=4319

Or send him a PM: a914guy

What happens if you use the 996 part number rear calipers (still non S) ?
i.e. part numbers 996 352 421 & 996 352 422, (rather than 986-352-423-01 & 986-352-424-01 as stated below) ?

I see Luke asked this question way back then but I don't see an answer. ( I have some of these 996 part number rear calipers and need to know if I can use the adaptors and whether to use SC 20mm rotors or 24mm Carrera ones on the rear.
Regards
Andrew

Andy - did you flip the link lines and the bleeders on the front brakes so that the larger cylinder is at the bottom? Recall that on the Boxster the calipers are the other side of the strut (inboard).

I've seen some expensive 911 builds where people have forgotten (or were unaware) of this. Not sure it makes a huge difference to stopping power, probably just uneven pad wear....

Anyway,

- Tony

PS. Looking back through the thread, I see the issue has been brought up already; oops.

Yes on the fronts. Running 15" fake Fuchs with no issues,

- Tony

I just put this setup on my car yesterday:

- Carrera front rotors / Boxster front calipers
- SC vented rear rotors / Boxster rear calipers

The front calipers are swapped left to right and vv.

7X15 and 8X15 Fuchs easily fit.

Someone mentioned bolts not mounted in shear... all are mounted in shear, yes.

I set up the rear E-Brake with 69-73 type 911 shoes. Cables will run to the bottom, not through the trailing arm nor with a lever mechanism. I welded parking brake brackets in a new location. This alteration was easy.

Anyway, I highly recommend this setup.

Don't give up on the Wilwoods... do a search on my user name and Wilwood... actually easy to make the spacers...

I've got the same setup with Boxster calipers and 19mm master. Thoroughly pressure bled the system twice and still getting soft pedal. Yes, I first bled the master and both valves on each caliper. And all bleed valves are up. And using that Ate high temp fluid.

One thing bothered me... when I opened the switch on the master, nothing came out. Is that normal? It's been a few years, but I'd swear that fluid bleeds there on 911 masters.

Contributing to this thread revival...

I have Early ‘S’ Calipers rebuilt by PMB and never used, and am toying with switching to Boxster or larger brakes for the look, as I understand from Eric that the ‘stopping power’ will be equal.

I’m wondering, can I just purchase the adaptor and caliper and swap these?

Sorry for the multiple-post, photos for reference. Heads up, these may be in the classifieds soon (shameless plug)....

Click to view attachment

I mounted Boxter front calipers, with the "u" brake fluid tube swopped position (causes the correct pistons leading), and 911 Carrera rotors in front. Left the refurbished 914 brakes on the back (PMB), with a refurbished proportioning valve (PMB). Kept a good order 19mm Master Cylinder and SS braded brake lines all previously installed. All of this on my converted 914-6 (2.7 L). This setup feels perfect under all serious breaking challenges.

Hi there,
On the way to build a 914GT, 5lugs and 911 e-brake mod ready on the rear but concerning Boxster calipers evo, I can't find nowdays adapters to match SC rotors (20mm) with these calipers (S or notS) like RJ did. => Anyone has a link to a solution in 2023 (only found adapters for boxster rotors with offset not compatible of e-brake mod...)

Furthermore, I have 996.352.421/422 calipers and not 986.352.xxx ones, like others folks here; the question about the technical difference and compatibility was raised on that thread ... but not answered; any tip ?

Thanks for your help
Vincent, France

The Boxster brake setup is early (non S) calipers and 24mm Carrera rotors.

Thanks for fast reply mepstein. It's for rear. A link to such adapter ? can't see on 914-6Werkshop ) Little bit confused: boxster 996.352.42X rear calipers in my hands (so S type?) have pins that allow only 20mm rotors...

From my first post in this thread:

My caliper pins are rubbing on my rotor and I hope to get some advice from this group. The car is a ‘70 914/6 (factory) that was restored as a GT tribute about 15 years ago.

It is running 1st gen Boxster calipers (986-351-421) on a 911 strut (911-341-041) with a misaligned rotor, The rotor is unknown, but is 24mm thick, 11” diameter and is not centered in the caliper. It looks like I might have the wrong rotor on this set up. The questions at this point are:
1. where is this strut from
2. is the Boxster caliper an okay fit (seems spot on from what I’ve read).
3. What rotor should I be running; and
4. what modification are needed to fix the misalignment? The Caliper needs to move .06” (1.5 mm) outward so the rotor will be centered between the pins. I can’t see how one could shim the calipers in the correct direction.

Pictures to follow…

The picture above is a view of the outer side. The next picture is of the inside of the rotor. You will notice the pin is riding on the outside surface of the rotor and pics of the inside of the caliper shows the pin about 3mm away from the face of the rotor.

@davenorcal

From my first post in this thread:


Post #4 and #5 in this thread show the milled down adapters to allow the calipers to be centered over the 24mm rotors.

@sirandy - Thank you. I read that and I could not visualize how inserting an adapter solved my problem. It looked to me I needed to shave 1.5mm off the face of the caliper where it seats to the flange of the strut for the caliper to go in the needed direction. Clearly, I’m missing something.

Please send pics of the back side so I might see the configuration, if possible. Thanks again!

Also, after re-reading the string I figured I’d reach out to @a914guy to get the lowdown on his adapters. Once I see the adapter in place it might sink into my thick skull.

@davenorcal
You already have the adapters mounted to your calipers. I can clearly see them in your pictures.
I milled down the adapters so the calipers end up centered on the 24mm rotors.

And as mentioned, i also shaved down the pins.


PS: Yours don't appear to be the Rich's adapters, unless he has a new design. But it can't hurt to contact him anyways.

Hi Guys,

I happen to have a set of Boxster NON S calipers rebuilt by Rick several years ago with his adapters set to go on my 85 carrera front end with Elephant Polly Bronz.

Just so you guys can see what these boys look like.


Best Bob B


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@sirandy - Dang, you are so right. I took pics of the back side so everyone can see them from another angle and see the left adapter is stamped “RTB 911F-MBC”. Thanks for hanging in there with me on this!

@Burton73 - thanks for your pics…helpful.

Click to view attachment

One of the other things about running Boxster calipers on the rear is that you have to grind off the bottom edge of the inboard pad. Otherwise they hit the adapter and won't go in far enough to put in the pins.

I'm showing that in post #7:
http://www.914world.com/bbs2/index.php?s=&...t&p=1634381