Boxster transmission adapter plate, Relocated starter Options

[r_towle]

Guys,
In response to another thread about subarus, someone posted a link about a shop in AZ that is making an adapter plate kit to bolt up a boxster transmission to a Subaru motor.

Wondering if he sold a kit, or just did all the work, I reached out to him.

He does in fact sell a kit which requires milling out some of the bell housing, but then you can mount a starter.

Assuming much of the flywheel and clutch would not work, this might be a good place to start for someone who races, wants a more modern transmission, a cable shifter, and would like to remain all Porsche....

Naro...


Link to site for pricing etc.
http://www.boxsterengineconversion.com/par...ith-prices.html

[naro914]

Did you ask if it work with a Porsche 3.2 engine?

[r_towle]

It's a flat plate of aluminum.
Holes need to be drilled for whatever motor you choose.

The hard part will be clutch and pressure plate, and flywheel.

It will work, yes, but the setup he sells is for a Subaru..
All the dimensions for the pressure plate offsets would be wrong..

Bet he could figure it out for you,,,,some really nice work on his site.

Rich

[precisionchassis]

It will only work with a Subaru engine and uses stock style Boxster/Cayman clutches. If you wanted to use an air cooled Porsche engine, you would be on your own.

[rick 918-S]

That is really not hard to do. I made my adapter plate for the Alien in my garage with a center punch and a hand drill. Many thousands of miles crossing the country is proof it works. Just takes some planning.

[bulitt]

I bet KEP could do this quickly. He already has plates for the Trans, and plates for the Suby. Just some CNC programming?

[CptTripps]

This could be real interesting, but I wonder if it wouldn't be easier at the end of the day to just find a way to cram the Boxster motor in there WITH the trans that it's already mated to.

If you are mounting a Subaru motor to it, you're saving weight and with the right mods, getting (about) the same HP. The Subie trans when converted to 2WD is pretty solid, and there are a lot more/easier mods/parts for the setup.

I'm glad to see people engineering other ways around this, but I am still happy with the path I took on using the Subie motor/trans.

[mepstein]

This could be real interesting, but I wonder if it wouldn't be easier at the end of the day to just find a way to cram the Boxster motor in there WITH the trans that it's already mated to.

If you are mounting a Subaru motor to it, you're saving weight and with the right mods, getting (about) the same HP. The Subie trans when converted to 2WD is pretty solid, and there are a lot more/easier mods/parts for the setup.

I'm glad to see people engineering other ways around this, but I am still happy with the path I took on using the Subie motor/trans.

I don't think people are thrilled about boxter motors. At least the ones with the IMS issues. Blown motors at 60K is one reason boxters sell so cheap. I like the idea of putting a subie motor into a blown boxter but also think there would be interest to adapt a boxter trans to an aircooled 6 in a 914. It would give us another option to the typical 915 trans swap.

[CptTripps]

... think there would be interest to adapt a boxter trans to an aircooled 6 in a 914. It would give us another option to the typical 915 trans swap.

I agree fully with this part. It gets pretty tight back there though. The boxster trans is pretty big IIRC. If you had a 3.6 or something extreme in there, I can see needing the better trans.

The cable-shift alone makes the mod worthwhile if you ask me. Even sitting in my car, not running, shifting through the gears is tight and quick. I can't wait to get it on the road and see what it's like to have a 914 where I don't need to "hunt" for a gear.

[r_towle]

That was kinda my point.
Subaru to Subaru is simple and well thought out.

Using a boxster transmission with the relocated start....well that was the first time I had seen anyone do more than just talk about the idea.

He went to the length of actually doing it.
Could someone copy him, maybe....but why bother.
He sells a kit....albeit it's just for a Subaru motor...

Taking his kit one more logical step to mate the boxster transmission to an aircooled porsche motor is a big plus and might sell even better.

For us, it may be a real and viable alternative to dumping money into an old 914 transmission that in the end still lacks a lot of the more modern things we expect.

Having a modern tranny solution is really interesting.

[naro914]

^^ Agreed
I have no interest in a Subaru motor. I want to keep it Porsche. There are A LOT of 914/6 conversions out there - I would suspect many more than Subie conversions. i would think if we could find a reliable, fairly simple way to mate up a Boxster trans to those, it would be a big win.

[r_towle]

And this seems really close.
Boxster transmission
Starter relocate
Boxster clutch

Just need to setup a flywheel for your application, and drill different holes for your motor....which would be the same for any of the six cylinder motors...

[ClayPerrine]

Looking at the specs in PET and online, the Boxster and 964/993 clutch disks are teh same diameter. Both cars use a dual mass flywheel. But the Boxster uses a push type clutch, and the 964/993 uses a pull type.

I don't have any of them here, but I suspect the bolt pattern is the same for the pressure plate attachment. So IF you could bolt the Boxster pressure plate to the 964/993 flywheel, then there is no custom clutch parts needed. But you still need the adapter plate for the trans, and a place to mount the starter. The adapter plate may make the engagement of the pilot bearing a little short, and the throwout bearing stroke a little longer.

I would use the aftermarket racing flywheel to eliminate the dual mass setup, and use the aftermarket clutch throwout bearing that incorporates the slave cylinder into it. A spacer could be made the same thickness as the adapter plate for it.


(IMG:style_emoticons/default/idea.gif)

[BIGKAT_83]

And this seems really close.
Boxster transmission
Starter relocate
Boxster clutch

Just need to setup a flywheel for your application, and drill different holes for your motor....which would be the same for any of the six cylinder motors...

Looks a little harder than that. From the picture thread and damn nice.

[Chris914n6]

I don't suppose someone has a CAD file of the 914 engine on Boxster trans bolt holes they would care to share?

I don't have a Boxster trans available and wanted to see if was feasible to redrill my Nissan adapter plate.

[bulitt]

The pics above are from member "221kw914" - Alex.
I pm'ed him to see if he has a template.

Also, I emailed KEP. They manufacture an adapter for boxster to SBC & LS engines but not Suby or Porsche.

[got914?]

I don't suppose someone has a CAD file of the 914 engine on Boxster trans bolt holes they would care to share?

I don't have a Boxster trans available and wanted to see if was feasible to redrill my Nissan adapter plate.

Ever get anything on this ?

[Chris914n6]

Found this on Rennlist.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i94.photobucket.com-431-1413841627.1.jpg)

Nothing larger than a 228mm clutch will fit inside the 4 bolt pattern. The adapter plate above pretty much explains it. 1" Flywheel spacer to stock 240mm pieces. There are VW/Audi sprung discs to choose from. The Box/VW/A PP might bolt up to that 993 fly or be T/O bearing compatible.

As for me, I've got a built tall gear box and only 260hp so not really worth all the R&D time and cost. Hydraulic clutch should fix my only big issue. Maybe do cables as the rod is a tight fit around the oil pan.

[Mike Bellis]

I'm running an 11lb VW/Audi lightened flywheel with a SPEC Stage 3 clutch. It works with both my Boxster 5 & 6 speed trannys. I also run the cheap ($) VW slave cylinder instead of the expensive ($$$) Porsche unit that is exactly the same except the hydraulic fitting. 034 Motorsport sells fitting adapters with a plug and play -3AN end. It makes it easy to install with a Wilwood or Howe type master cylinder.

Here is a pic of a 901 and Boxster 5 speed with the axles lined up. The center line distance from the axle center to the edge of the bell housing is shorter on the Boxster. A 1" adapter would put the tranny in better alignment with the engine in stock location. With the axles lined up, the end of the tranny is in about the same place.

[El Vikingo Tropical]

And this seems really close.
Boxster transmission
Starter relocate
Boxster clutch

Just need to setup a flywheel for your application, and drill different holes for your motor....which would be the same for any of the six cylinder motors...

Looks a little harder than that. From the picture thread and damn nice.

Do have any news about the 3.6L engine fitted to the Boxster trans?