Subaru transmission in place of a 915

[Tremelune]

I've been ruminating about this for quite some time. I have a 3.6 pushing a 915, and I'm not happy with the gearing (close ratio for track use with a short top gear). One day it will come out, I'll rebuild it with new gears, and thousands of dollars later I'll have a 915 that shifts decently for a while. I think I could get four gears in a 930 that shifts well and handles more power for twice the cost, but I'm starting to wonder if a similar amount of money could have me driving around with six modern gears instead.

I've read about people putting Subaru transmissions in 914s:

http://www.914world.com/bbs2/index.php?showtopic=110990&view=findpost&p=1368310

914World.com - The fastest growing online 914 community!



I've read about people putting 915s in 914s with an adapter from WEVO:

Transmission > Porsche 915 WEVO to 914 By Patrick Motorsports Porsche & Mid Engine Performance Specialists



Subaru Gears sells a kit for reversing the output of Subaru transmissions for use in various old VWs, as well as "930" flanges to mount the CVs to. A salesmen told me he's seen one go into a 912 with a Subaru motor, but I haven't seen pictures yet.



If a 915 fits in both a 914 and a 911, and a Subaru transmission fits in a 914, what are the largest barriers for putting a Subaru transmission in a 911 in place of a 915?

[metalracer]

Cool idea and seems plausible (tho I have no direct experience with the Subs). I'm interested to see where this goes.....

[pksystems]

'68 Porsche 912 conversion - 2005 STi EJ207 - NASIOC

Subaru shifter has to come through in a different location then the stock Porsche. Porsche is 6 oclock, subaru is 10 oclock.

[Elombard]

Matt Monson at guard transmission knows 915s and Subaru transmissions. He once commented that he was doing a lot of transmissions for the Factory five mid engine subaru kit (cant think of the name). He had some concerns about the strength of the Suby trans when converted to 2WD. He might be a resource. I love the idea of a lower cost modern trans. Especially if the mod was reversible.

[Cherry Bomb]

The right Subaru trans will handle up to 450hp on the "street".

Adapters for offsetting the shift rod to output can be made or purchased for VW applications, so I imagine the same for 911 apps.

After flipping the R&P, converting to 2wd via SubaGears kit it will be able to handle 3.6. The WRX puts out similar or more power/torque depending on model & origin. JDM is more balls.

A full Subaru STI swap would be sweet in a 911 for many reasons other than resale.

There is no kit for the six speed, yet.... but that may be remedied by the time you finish this sentence.

The Subaru 6cyl 3.0R has big potential.

We have recently installed a JDM WRX engine/trans into this 62 Kafer. Lots of cutting, some welding and swearing but it's going together nicely. This one is 260hp/260trq in factory trim. After the transplant and mild mods it should be knocking on 300hp's door. This is a 1675# Street Bug. Should be interesting. ;-)

[Cherry Bomb]

The weight savings alone is a huge plus. The Subi six is just a fraction of an inch bigger than the four banger. Not much heavier either. If my 3.2 takes a nap I am ready to do the swap so I can enjoy the 911 and keep my house. Haha.

[Coastr]

Well, off topic but if you like swapped subaru-VW conversions

https://m.youtube.com/watch?v=hpb2Him9CUo

[Cherry Bomb]

That's what I'm sayin'....lol.

[Lake Guy]

Well that skoobie doo transplant looks like lots of fun - I'd be interested to see how effective the engine cooling system turned out to be.

[Tremelune]

Originally Posted by pksystems

'68 Porsche 912 conversion - 2005 STi EJ207 - NASIOC

Subaru shifter has to come through in a different location then the stock Porsche. Porsche is 6 oclock, subaru is 10 oclock.

What is the clock in this metaphor? Unfortunately, the vast majority of the photos from this build are gone, though there is a shot of the pedals and shift tower here:

NASIOC - View Single Post - '68 Porsche 912 conversion - 2005 STi EJ207

After seeing the level of metalwork being done on rust buckets around here, I would be willing to cut/weld some interior metal to accomplish the task, but it always makes me very, very wary to cut anything.

It also looks like he went with a hydraulic setup...Is that simpler than running cables?? Once you get into G50 conversion territory in terms of resource outlay, there is very little reason to go Subaru. That said, every G50 conversion I've researched ended with "this costs a lot", so...

[Tremelune]

I scared up some of the missing photos from that 912 conversion.

901 vs TY758 5-speed from a 2010 WRX (the AWD bit was coupled, so it is a shortened version that is FWD-only...The front-wheel portion of the transmission drives the rear Porsche wheels):





I can't quite tell where the Subaru motor ends and the Subaru transmission begins in this next shot, and I don't know where a Porsche motor (or LS) would normally sit. I'm wondering if it is definitely necessary to cut that crossmember if using a different motor:







The transmission tunnel:



Slave cylinder (the red bit is the Subaru motor intake):



It gets a bit ugly in the interior, but not much worse than a Hargett setup.



The seat hump looks fiberglass, which raises the question of whether or not enlarging it in this manner was required, or if it was just a weight-saving attempt while already cutting in that area.

[Tremelune]

Specific measurements culled from that 912 thread:

Bell housing face to tip of shift rod housing: 73.5 (Porsche), 74.0 cm (Subaru)
Bell housing face to flange center: 16.5 (Porsche), 20 cm (Subaru respectively)

[Matt Monson]

Originally Posted by Tremelune

It also looks like he went with a hydraulic setup...Is that simpler than running cables?? Once you get into G50 conversion territory in terms of resource outlay, there is very little reason to go Subaru. That said, every G50 conversion I've researched ended with "this costs a lot", so...

Starting in 1998 all Subarus went hydraulic clutch. And in 2003 the gears were widened. There are both pull and push style clutches on different product lines. The pull clutch from a WRX has better clamping force and pedal feel.

I'm not sure anyone has ever made an adapter plate and flywheel to mate the Subaru gearbox to an air cooled engine.

[pksystems]

I thought there was more pictures in that thread. Good thing you found them.. They will help when I get back to my 912 project.

Notice the picture where the shifter is coming through the bump between the seats? That's the 10 o'clock position of the subaru transmission. I won't fit through in the same place as the Porsche transmission. The subaru linkage won't line up through the 911 tunnel.

[Ferrino]

I'd be very interested to learn more about a complete Scooby engine+tranny swap into a 911 chassis. Given the cost of air-cooled engine/tranny rebuilds these days, I'm questioning how hard I will end up pushing the car when it's back on the road: forget the "money shift" - it's now more of a "remortgage shift". For the money I could recoup in the current market for my very healthy 3.2 Carrera and turbo-look 915 w/ LSD, I'm thinking I could get a pretty neat STi setup with modern shifting and lots of aftermarket goodness (plus spare engine and tranny!).

[MichiganMike]

I've shifted Ron's car and with the WEVO shifter into the Subaru trans, its a beautiful thing. Not like a tractor-esqe like Porsche trans. I had the 6spd trans with my motor and it was quite large, too large for my car. Ron has the smaller 5 spd which is robust enough for the motor in his '68. Being that we have SWB cars, it was already a tight fit, but maybe better on a LWB. Another great thing on his setup is that his CVs are stout. I'm a little concerned about tearing through them on my set as i run 914 output shafts with stock SWB CVs. I believe Ron has 930 CVs, but not 100% on that. Also, BTW, Rons picture above through his tunnel is not FG, just looks that way from the picture.

Interesting question Tremelune, as Im not sure who (if anyone) makes an adapter from subaru trans to porsche motor. If so, how about putting a 3.6L into a WRX with a very large oil cooler up front?!?!

[Tremelune]

Indeed, though Subaru Gears does have adapters for a VW Type IV:

Subarugears

I'd like to convince them that there is a market for a Porsche motor adapter, but I fear the Porsche community is a little too precious about putting non-Porsche stuff in their cars, even though nobody has called the transmission the "heart" and "soul" of a car.

It is also worth noting that there is an adapter for the Chevy LS as well.

[puddy]

A friend of mine is doing a subie motor swap into his 1967 912, i'l'l send him this link, perhaps he'll post what hes doing. His Porsche buddies think he should keep it simple with a Porsche swap but I think he likes the idea of his Subie motor & trans costing less than a Porsche trans alone.

[-Levi-]

I'm in the middle of a 3.6 swap into my sc- I would love to have a better cheaper transmission in my car! this would be one heck of an upgrade if we can pull it off. do these trannys come with lsd by chance?>

[Tremelune]

Some have LSD on the front part of the diff (which would drive our cars) and some don't:

Subaru Transmission Chart

The aftermarket and community for these things is remarkable. It sure seems like you buy in any gear or diff you want, if you have the transaxle apart.