It was suggested I make this a stand alone thread so here it is. This will work for 4 or 5 lug wheels.
Parts
07,08 cayman, 05-08 boxster 2.7L (non-S) rotors.
298x24 front
299x20 rear.
Calipers 97-08 Boxster
07-08 Cayman
Adapter mount for rear caliper. Re-drilled rear hub or the soon to be released 5lug hub from URO. If you want to keep 4 lug have the Boxster rotor drilled.
Front hub that goes right onto the stock strut and can use 4 or 5 lug wheel. Front rotor mount adapter.
I have not tried but am told 15” alloy works.
Rear
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Front
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Once the URO rear hub is available (announced Nov 2020) this entire upgrade to Boxster brakes with 5 lug will be an off the shelf bolt on affair.
edit I believe it can be done for both early and late struts. the struts shown are late which was harder to work out.

Who makes the adapter?

I Worked with VDUBENGINEERING, Lanner Khan.

For you early strut guys the Sebro vented rotor for ball joint T3, Bugs, Ghias goes right on. Downside is that it is the rotor hub combo and any damage requires you ship another over from the Old World (expensive) as I have yet to find anyone that imports them. You can get 4 or 5 lug and cross drilled. I never got to the point of figuring out which exact caliper to use but I was leaning toward the vented BMW 320 and vented Volvo. it was not that hard to swap the pinch bolt for the friction fit ball joint. Did have to source bent strut tubes.
edit: early struts can be fitted with other caliper adapters from VDUBENGINEERING and hub above. Late struts pictured above.

Hi guys,

My name is Lanner. I built this setup. It uses new iron hubs with radial brackets for use with stock 914 spindles. Bearings and wheel seals are stock 914 and it's bolt on. It's a good option that doesn't require swapping out to 911 suspension. Please let me know if you have any questions about the setup.
Thanks
Lanner
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Thank you for posting.

This will get a lot of attention I think but will require a lot more pictures and description .

No mention about the emergency brake. Can the early 911 setup be added?



Edit; thank you for the additional pictures.

Very cool!

i do have a couple questions, since i have 5-lug fuchs(16") , but used the stock rotor and brakes in front with the rotor redrilled and new lugs pressed into the rotor, so currently i have all stock set up, but i do have 19mm 911 master cylinder, so my question is this: for my front if i converted over to this set up , what would i require? The boxster caliper and rotor, and the hub and spacer mounting blocks, is that it? and then source the new studs?(i want to use nuts not lug bolts)
@Lanner @djway


also fyi i have 914/6 5 lug hubs on rear so just using the stock caliper with stock 4 lug solid rotor drilled for 5 lug(PMB), so for rear i would just maintain my current set up , or, if i wanted the rear boxster caliper would i just get the new rotor and caliper and mount with adaptor block? seems the new rotor would just slide right on my current rear hub but new caliper with spacer would be required, OR a 914-6 or M caliper could be used too?

Djway has been a great help, measuring things for me and even sending me a strut to work with. I build custom brake setups for mainly the vw and Porsche 944 crowd, but I have worked on alot of different platforms. I didn't have a 914 to mockup on, so DJway sent me a spindle and has been of great help in getting this setup done.

As built, this setup has no parking brake. I could probably adapt a 911 or 944 style drum in disk setup, but would need a trailing arm to work with. Current rear setup is just a set of radial adapters for use with stock 914 rear hubs, either stock or redrilled to 5-bolt.

Here is a mockup pic of the front setup. Let me know if there is something specific you'd like to see. I can build the front (hubs and brackets) for about $550.

Thanks Lanner
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Great, thanks for the quick reply. rear is just add the radial adaptor and source the rotor and caliper. for front, source rotor and caliper and lugs/studs to be installed into the hub you supply along with the spacer for caliper mounting.

why wouldnt the S caliper work? is mount spacing different, or rotor size, or is it just the clearance with the rim, because i have 16" fuchs so while 15's may not clear, the 16's should , yes?

Phillip - this looks like a great solution for putting big brakes on a car but I would hesitate to say it’s the solution for every car. I would put a Carrera rotor next to your stock rotor and check the weight difference then X 4 for the car. Adding pounds of unsprung weight to a narrow body four will affect acceleration and handling. Everything is a trade off and it really depends what you are trying to achieve.

We did the Boxster caliper, Carrera rotor upgrade on a lot of 911’s that got 3.2 or 3.6 engines. It’s a nice upgrade from M calipers.

S calipers have 3.5” spacing and are different from Boxster caliper spacing.

Dr Phil,

Correct on front setup. You need the hubs and brackets. You can get some nice screw in studs from BMW shops or 034 motorsports.

Correct on rear setup, you'd just need the radial adapters. The 914 hub will accommodate the Cayman caliper without any work. Note you lose the parking brake.

I have this setup on my car (vw) with 19mm master and works well. It's been on there for over a decade. I'd suggest maybe a slightly bigger master (20.6) if you want a really tall pedal , but I've left good enough alone.

On 16 fuchs the calipers need a little massaging, and maybe a slight spacer 5mm unless you have the 951 Fuchs. Pic of massaging here:
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In general you need 16" wheels. Some 15s fit (mainly the spare tire alloys such as 928/993 15" spare or 951 spare

Thanks
Lanner

Here's a VW I built on the same brake setup, 16*7/8 wheels. Yum
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Mark, @mepstein , good point, there is a lot to consider before just jumping into this but exciting to see this is an option. maybe a better lower weight option is the alloy calipers that PMB has could work using this hub and adaptor, again, saving weight and not having to swap out the whole suspension for 911 when i already have good new other components.
Lanner, thanks for all the info and the pictures. i think you will get a lot of interest in this.

Phil

I agree mepstein, you are adding unsprung weight. It's all a tradeoff, so each vehicle has to be evaluated individually. This setup doesn have the advantage of large rotor diameter for brake torque and thermal capacity, without being too thick and heavy. Numbers below

Dr Phil, the S setup s too much imo. Here are the numbers

Cayman rotors 298*24F, 299*20R
BoxS 318*28F, 299*24R

Btw, the Carrera rotor (911) is 282*24F. I could probably make a rear adapter for a slightly smaller rotor such as a 944 rear 289*20 which would aid in fitment of 15" wheels. I've built such setups for vws with the Boxster caliper: (15*5.5 pictured)
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Super cool bug!

I would be curious to know more on that car... Engine, trans, rear IRS I suppose, looks like a 68 or 69 with earlier front fender and bumpers? Fun stuff. I bet @Mark Henry would be curious too...

Parking brake option...lol

@montreal914 , funny you should ask...are you in Montreal? That car is. 2332t1 EFI, built 091 trans, irs rear, a-arm front end, rack and pinion steering. It's a euro 71 iirc. Getting a turbo this winter..aiming for 300whp

Maybe. These adaptors are for Boxster calipers, which I think are 3.75 spacing. S calipers are 3.5" and M/Alfa calipers are 3.0".
These adaptors look like a great product to provide a Boxster caliper solution on our stock cars but you are going to have to do your homework and not assume they will work in every situation.
I don't know if Boxster calipers will fit under/in 6x16 wheels.

Lanner

Nice!!
Actually moved to the greater Los Angeles area 11 years ago, where I bough my long awaited 914.
Beetles were my first 3 cars over the span of 7 years. I had a 1776cc with KG front disk brakes, lowered suspension, and 3/4" sway bars front ant rear. Lots of fun!

Yep-2 of those tanks might weigh a few pounds-at least it’s not unsprung!

The Boxster are 130mm radial mount. Most 911 is 89mm axial (3.5") and the 914 stuff is 76mm (3").

@mepstein , thanks for the welcome.

@montreal914 , I'm a big air-cooled fan. I've never had a teener but they're growing on me. Here's my half-year driver:

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I found Lanner through an insane VW Fastback build on the samba.
I first brought up the idea of adapting to the early struts because they are basically the same architecture as the type 3 and other VWs ball joint setup, and already done. I then got the idea to see if he could adapt to the later strut as the only change was the step back ears which I knew could be worked around after doing BMW front calipers.
I got some buggered up struts from Bruce Stone to add late model ball joints to early struts (before I found Lanner) I sent one to Lanner and in no time he figured it out. We even discussed bearing loads. He sent me pictures and I said “let’s do it.”
I found used calipers but you can purchase at local FLAPS. I found an amazing deal at Rock Auto on a complete set of 4 high carbon coated rotors with pads. I already had some studs. You need to select those based on wheel and any spacers you may use. Lanner supplies mounting hardware.
As for parking brake I will either use an inline hydraulic lock or one of the Wilwood cable operated units that welds onto the trailing arm. I think the lock plus leaving in gear should suffice for the majority of situations I may encounter.
The only downside I have found is that the screw holes to fix rotor to hub don’t line up on Boxster rotors to 914 hubs. I didn’t spend much time on that and I could be missing something.
I have started research on another project that I will have Lanner bring to life but it will be a bit yet.

@Lanner Are those calipers S or just repainted? Lanner your bug is awesome. I have loved the "German Look" for years. Every now and then I watch videos of Bugs with big T4 engines hunting Porsche.

Don't know this bug, I have seen the silver bug. I've known of Lanner for some 20 years when he was out of Mississauga doing brake/wheel adapting for the GTA germanlook beetle crowd. I installed a weber carb cable linkage from Lanner last year and I've helped in doing a few wheel conversions using his parts, always top notch well thought out kit.
Lanner I've met you in passing at a few shows long time ago at the Jitter bug and maybe Haugen's. I have a blue '67 with a 2600cc T4 conversion.

@djway , the pictured calipers are just repainted nonS.

@Mark Henry, thanks for the kind words. Yeah we have met in the past. I also have some vague memories of maybe coming by your place in early 2000s to look at a car you were selling....not exactly sure if that was you...it was in eastern ON so maybe. My mind is getting mush lol

@djway @Lanner - thank you guys for all of your hard work investigating this solution! I for one would definitely be interested in a front setup, but my goal would be to keep my 15" Empi-style rims. Not sure if there is a setup that would support that. The purpose for me is to increase the cooling efficiency on the front brakes by going vented. Aesthetics aren't important.

I would guess that Lanners solution above or spacers would work.

@ThePaintedMan . The hubs are dual pattern, so you could use 4*130mm wheels. Some clearance holes in the rotor would be required.

The 298 rotor will require a 16" wheel, but I could figure out a combination for you for 15" wheel if you're interested.