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914World.com _ 914World Garage _ Boxster Calipers, got them installed today!
Posted by: SirAndy Feb 27 2012, 01:12 AM
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:
Posted by: SirAndy Feb 27 2012, 01:12 AM
RJ Adapters:
Posted by: SirAndy Feb 27 2012, 01:13 AM
Test fit in the rear:
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Posted by: SirAndy Feb 27 2012, 01:14 AM
Sharpie marks for milling the adapters so they would center over the 24mm rear rotors:
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Posted by: SirAndy Feb 27 2012, 01:15 AM
Milled down rear adapter mounted:
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Posted by: SirAndy Feb 27 2012, 01:16 AM
Rear Caliper bolted up:
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Posted by: SirAndy Feb 27 2012, 01:17 AM
The inner rear pads need to be shaved down a bit as they would otherwise hit the mounting ears (shaved one on the left):
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Posted by: SirAndy Feb 27 2012, 01:18 AM
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:
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Posted by: SirAndy Feb 27 2012, 01:19 AM
Everything in place. I added some blue loctite to the mounting bolts for the final assembly:
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Posted by: SirAndy Feb 27 2012, 01:20 AM
One more, rear all installed:
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Posted by: SirAndy Feb 27 2012, 01:21 AM
The front went on much easier. Here's the adapter mounted:
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Posted by: SirAndy Feb 27 2012, 01:22 AM
Test fitting the front:
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Posted by: SirAndy Feb 27 2012, 01:22 AM
And final assembly:
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Posted by: SirAndy Feb 27 2012, 01:22 AM
Time for a shower and some beer!
Posted by: Cairo94507 Feb 27 2012, 08:09 AM
Wow that should give you some serious stopping power. Sweet.
Posted by: jaxdream Feb 27 2012, 09:46 AM
Those look fantastic!!!!!!!!! 
Jack
Posted by: jsconst Feb 27 2012, 10:14 AM
Wow, long day, glad to hear you got it done. Looks great.
Jeff
Posted by: URY914 Feb 27 2012, 10:16 AM
Nice work. Damn those are big.
Posted by: pcar916 Feb 27 2012, 10:22 AM
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!
Posted by: stuttgart46 Feb 27 2012, 11:42 AM
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.
Posted by: andys Feb 27 2012, 12:10 PM
Andy,
Which Boxster caliper did you install. Actually, I don't know anything about Boxster calipers; are standard different than "S" ?
Thanks,
Andys
Posted by: ClayPerrine Feb 27 2012, 12:33 PM
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.
Posted by: SirAndy Feb 27 2012, 02:16 PM
Nice work. Damn those are big.
They are big! But they are actually *lighter* than the Carrera calipers i took off ...
And light is gud.
Posted by: SirAndy Feb 27 2012, 02:18 PM
These are standard Boxster calipers.
If i'm not mistaken, the "S" calipers are different and won't work with the RJ adapters.
Posted by: andys Feb 27 2012, 02:23 PM
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
Posted by: SirAndy Feb 27 2012, 02:25 PM
19mm
Posted by: PeeGreen 914 Feb 27 2012, 02:52 PM
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.
Posted by: slivel Mar 19 2012, 05:44 PM
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.
Posted by: Cracker Mar 19 2012, 07:14 PM
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...
Posted by: slivel Mar 19 2012, 08:02 PM
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.
Posted by: okieflyr Mar 19 2012, 08:19 PM
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).
Posted by: slivel Mar 19 2012, 08:38 PM
Pagid Black - but it's a track only car.
Posted by: campbellcj Mar 19 2012, 08:41 PM
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.
Posted by: SirAndy Mar 19 2012, 09:26 PM
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...
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 ...
Posted by: r_towle Mar 19 2012, 09:57 PM
Is there an emergency brake as part of this solution?
Posted by: SirAndy Mar 19 2012, 10:14 PM
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.
![popcorn[1].gif](style_emoticons/default/popcorn[1].gif)
Posted by: Cracker Mar 20 2012, 04:23 AM
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!
Posted by: Philip W. Mar 20 2012, 07:57 AM
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 ...
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Posted by: Aaron Cox Mar 20 2012, 08:25 AM
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)
Posted by: Steve Mar 20 2012, 08:39 AM
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.
Posted by: SirAndy Mar 20 2012, 11:27 AM
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)
Just bolted them on and ignored the pistons. Mounted so the bleeders are on top.
I doubt it will make any noticeable difference ...
Posted by: Aaron Cox Mar 20 2012, 11:58 AM
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 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
Posted by: SirAndy Mar 20 2012, 12:05 PM
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.
Posted by: Aaron Cox Mar 20 2012, 12:08 PM
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!
Posted by: okieflyr Mar 20 2012, 02:51 PM
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 ...
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.
Posted by: SirAndy Mar 20 2012, 03:49 PM
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.
Posted by: Aaron Cox Mar 20 2012, 03:52 PM
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.
Posted by: jim_hoyland Mar 20 2012, 04:23 PM
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
Posted by: Aaron Cox Mar 20 2012, 04:25 PM
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?showtopic=77197&st=0
Where did you find those Jim?
Posted by: jim_hoyland Mar 20 2012, 04:28 PM
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....
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
Posted by: Aaron Cox Mar 20 2012, 04:32 PM
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....
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
Right ON! I'm curious how he did it? Can you post a pic? Will they also work with 15" wheels?
Thanks Jim!
Posted by: jim_hoyland Mar 20 2012, 04:35 PM
Her ya' go... 
I'm not sure the pic where the adapter is mounted is oriented correctly...
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Posted by: okieflyr Mar 20 2012, 05:11 PM
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.
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.
Posted by: Aaron Cox Mar 20 2012, 06:12 PM
Wow, Jim.
Those look scary thin at the corners of the mounting hole. Interesting!
Posted by: SirAndy Mar 21 2012, 11:08 AM
Those look scary thin at the corners of the mounting hole. Interesting!
Posted by: seanery May 29 2012, 09:53 PM
It's been 2 months now, Andy. How do you like them?
Posted by: seanery May 29 2012, 09:54 PM
Those look scary thin at the corners of the mounting hole. Interesting!
I was excited about them, but yeah, that's scary!
Aaron, what's your front setup?
Posted by: SirAndy May 30 2012, 01:35 PM
They work great!
Posted by: Steve May 30 2012, 06:14 PM
I love mine!! They work great and they don't squeak like the 944 Turbo brakes I had before.
Posted by: tim_nd May 30 2012, 08:52 PM
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.
Posted by: jim_hoyland May 31 2012, 08:13 AM
I have not mounted those adapters. They are in a drawer....
Posted by: Luke M Jul 9 2012, 06:47 AM
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 ) .
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Posted by: CptTripps Aug 30 2013, 01:28 PM
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?
Posted by: Luke M Aug 30 2013, 04:00 PM
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.
Posted by: CptTripps Aug 30 2013, 05:15 PM
I think you may have a set of fronts on the rear...
Posted by: Luke M Aug 30 2013, 05:38 PM
From the Pelican site.
http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_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
Posted by: Jeff Hail Aug 30 2013, 06:01 PM
From the Pelican site.
http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_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.
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Posted by: Jeff Hail Aug 30 2013, 06:10 PM
and pads
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Posted by: CptTripps Aug 30 2013, 07:08 PM
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.
Posted by: Ecke Liebhaber May 8 2015, 04:47 AM
Will the Boxster calipers fit under 15" Fuchs?
Posted by: SirAndy May 8 2015, 10:23 AM
They should, i run them under 15" cookie cutters ...
Posted by: ClayPerrine May 12 2015, 09:12 PM
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.
Posted by: SirAndy May 13 2015, 10:57 AM
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.
Posted by: madmax914 May 13 2015, 03:13 PM
Andy, can you pass on Rick Johnson's information, his adapters look so much "beefier" than the other adapters I've seen.
Posted by: GermermanCarGuy May 13 2015, 03:53 PM
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
Posted by: SirAndy May 13 2015, 05:46 PM
You can find his contact info here:
http://www.914world.com/bbs2/index.php?showtopic=4319
Or send him a PM: http://www.914world.com/bbs2/index.php?showuser=11
Posted by: amallagh Mar 17 2019, 06:58 PM
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
From the Pelican site.
http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_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
Posted by: Retroracer Mar 17 2019, 07:51 PM
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.
Posted by: Retroracer Mar 17 2019, 07:53 PM
Will the Boxster calipers fit under 15" Fuchs?
Yes on the fronts. Running 15" fake Fuchs with no issues,
- Tony
Posted by: roblav1 Nov 1 2019, 08:01 PM
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.
Posted by: wndsrfr Nov 2 2019, 08:03 AM
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!
Don't give up on the Wilwoods... do a search on my user name and Wilwood... actually easy to make the spacers...
Posted by: roblav1 Jun 10 2020, 09:27 AM
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.
Posted by: RiqueMar Jun 10 2020, 09:42 AM
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?
Posted by: RiqueMar Jun 10 2020, 11:18 AM
Sorry for the multiple-post, photos for reference. Heads up, these may be in the classifieds soon (shameless plug)....
Posted by: 914Toy Jun 10 2020, 02:38 PM
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.
Posted by: vfe95 Jan 25 2023, 03:20 PM
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
Posted by: mepstein Jan 25 2023, 03:41 PM
The Boxster brake setup is early (non S) calipers and 24mm Carrera rotors.
Posted by: vfe95 Jan 25 2023, 03:53 PM
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...
Posted by: SirAndy Jan 25 2023, 04:51 PM
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:
Posted by: davenorcal Apr 18 2023, 11:24 PM
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…
Attached thumbnail(s)
Posted by: davenorcal Apr 18 2023, 11:27 PM
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.
Attached thumbnail(s)
Posted by: SirAndy Apr 19 2023, 12:19 AM
@http://www.914world.com/bbs2/index.php?showuser=25605
From my first post in this thread:
...
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.
...
Post #4 and #5 in this thread show the milled down adapters to allow the calipers to be centered over the 24mm rotors.
Posted by: davenorcal Apr 20 2023, 12:30 AM
@http://www.914world.com/bbs2/index.php?showuser=25605
From my first post in this thread:
...
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.
...
Post #4 and #5 in this thread show the milled down adapters to allow the calipers to be centered over the 24mm rotors.
@http://www.914world.com/bbs2/index.php?showuser=179 - 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 @http://www.914world.com/bbs2/index.php?showuser=11 to get the lowdown on his adapters. Once I see the adapter in place it might sink into my thick skull.
Posted by: SirAndy Apr 20 2023, 09:29 AM
@http://www.914world.com/bbs2/index.php?showuser=179 - 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 @http://www.914world.com/bbs2/index.php?showuser=11 to get the lowdown on his adapters. Once I see the adapter in place it might sink into my thick skull.
@http://www.914world.com/bbs2/index.php?showuser=25605
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.
Posted by: burton73 Apr 20 2023, 11:27 AM
@http://www.914world.com/bbs2/index.php?showuser=179 - 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 @http://www.914world.com/bbs2/index.php?showuser=11 to get the lowdown on his adapters. Once I see the adapter in place it might sink into my thick skull.
@http://www.914world.com/bbs2/index.php?showuser=25605
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
Posted by: davenorcal Apr 20 2023, 09:42 PM
@http://www.914world.com/bbs2/index.php?showuser=179 - 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!
@http://www.914world.com/bbs2/index.php?showuser=7414 - thanks for your pics…helpful.
Attached thumbnail(s)
Posted by: ClayPerrine Apr 21 2023, 11:24 AM
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.
Posted by: SirAndy Apr 21 2023, 11:39 AM
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=&showtopic=170890&view=findpost&p=1634381
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