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Posted by: gfg3 Aug 11 2015, 03:39 PM

OK, I've got a line on a very inexpensive Boxster S 6-speed. And I've got my '75 914 2 liter. I've checked through lots of posts here and at Pelican and other sites to see if anyone has actually used this trans in the 914. Lots of folks say it can't be done, but to me that's just a challenge. And there are hints that it has been done, but I need to know if anyone has actually done this. Yes, I know the starter issue and a few of the other "challenges". Anyone?

George

Posted by: Dave_Darling Aug 11 2015, 03:51 PM

It's been done several times, hooking up to various non-stock motors. (Audi, Chevy, etc.) Just scroll down for discussion of the Small-Block Chevy version, and do a search for Mike Bellis' thread on his engine-of-the-month conversion car. He might have even had a rotary hooked up to a Boxster trans?

IMHO, the Boxster trans is not a particularly good idea with the Type IV engine. At the very least, it isn't needed--and it's quite a bit heavier. Plus you have to work out how to mount it, how to hook up the clutch, the reverse lights, the shift linkage, and the starter. Not to mention drive axles. It's probably easier to get a cable-shift setup from somewhere else, and buy two or three stock 914 transmissions to swap if you kill one. That'll still probably cost less than getting the Box trans all hooked in correctly.

--DD

Posted by: Mike Bellis Aug 11 2015, 05:31 PM

You will need a custom adapter, flywheel, clutch and you will need to machine and weld the transmission to create a starter pocket.

If you can do all that, then yes it can be connected to your 2.0L T4.

Posted by: gfg3 Aug 11 2015, 05:37 PM

Thanks for your input Dave. I just had to know if anyone matched a 6-speed Boxster trans to a type IV. The Boxster trans is sweet, and I've driven and raced 914s and that trans is....well, not so sweet. Plus I had this (almost) free 6-speed available. Just a thought....

Posted by: Andyrew Aug 11 2015, 05:44 PM

Might I suggest the 5 speed from the Audi A4/Vw Passat.

These can be found every day at the junkyard or from people parting them out.

Dime a dozen and if you paid more than 150 for it you didnt do your shopping very well (last one I bought was 60 bucks...)

Posted by: Andyrew Aug 11 2015, 05:45 PM

Its essentially the same trani but its been said they shift smoother. Not to mention there are a million gear combos you can use..

Posted by: Mike Bellis Aug 11 2015, 05:53 PM

Sell me the 6 speed. It will bolt right up to my Audi motor.

Posted by: Mueller Aug 11 2015, 07:20 PM

Good info there....

Posted by: gfg3 Aug 12 2015, 04:42 AM

Thanks everyone. Sounds like it may be too hard. But then again, I have a couple of bizarre ideas about how to mate the trans that I'll have to think about. But for now, it's something I'll fiddle with once the winter weather hits.

Posted by: brant Aug 12 2015, 07:53 AM

I Would worry about the gearing to a type 4

Posted by: gfg3 Aug 12 2015, 10:08 AM

Gearing doesn't appear to be too bad, at least at first glance. If you consider that the Boxster has a higher (lower numerical) rear ratio and then work through the individual gear ratios, here's what I get for total ratio at the rear (not definitive...I did the math quickly):

Boxster
1 13.14
2 7.57
3 5.23
4 4.20
5 3.51
6 2.89

914
1 13.69
2 8.37
3 5.58
4 4.10
5 3.14
6 -----

I haven't charted out all the shift points vs speed, but a couple of observations: Assuming 914 torque is sufficient to launch using the lower numerical Boxster 1st gear, the std 914 gearbox would pull a little better through 3rd gear. Once in 4th, Boxster pulls a little better. But frankly, now that I look at it, that 6th gear would probably be useless in most instances unless you really are looking for long legs and gas mileage. Again, not sure if the 4-cyl 914 has the power to even use that 6th gear effectively.

Oh well, nice mental exercise.