Subaru Conversion, CSOB style... Options

[jsteele22]

I've been thinking about what it would take to do a Subaru install
into my 914, and making it as inexpensive (and as home-brew) as
possible. I have a friend who is a machinist with a lot of enthusiasm
for the project, and a nice shop. He's done a couple of adapter plates
before, so I'm confident in that part. What I'm more curious about is
the flywheel. My idea for this is to take the stock Subaru flywheel
and machine it down to a radius of 4-5-ish inches, and then bolt a
stock Porsche (okay, VW) flywheel to it. So the Subaru FW becomes
just an adapter hub. Then, the thickness of the adapter plate is
chosen to get the input shaft to reach the proper position in the
friction plate/pilot bearing.

What do all you hybrid gurus out there think of this ? Am I
overlooking anything glaringly obvious ? (I haven't seen the pieces
in person, just in Haynes & on EBay.) Sure, the assembly will have to
be balanced carefully, but I think we (he) can handle that. The
engine I'm looking at is an EJ25 (165-ish HP) or, more realistically,
an EJ22 (130-ish), so it won't be an axle-snapper like some of you SBC
folks are driving.


Another issue is the engine mount. I've seen pics of Scott's, and
another one (tube steel) that I think Friid had made up, but not the
ultra-secret Renegade design. One idea I had on this is to not use
the stock Suby engine mount points, but instead make the adapter plate
several inches wider than the bell housing. Then each side of the
adapter plate could have an "L" shaped bracket bolted (sideways) onto
it; the bottom of the L would bolt vertically onto the plate at two
points, and the back of the L would point (horizontally) forward to
hang from a cross bar, either in the conventional (lower) position, or
up high across the top of the engine bay. This would take essentially
all of the torque off of the mounting bar bolts, and would leave an
open path for the shift linkage. In practice, I'm sure there would
need to be a little cross-bracing to prevent side-to-side motion, and
also to keep the L from straightening. Again, oh learned ones, what are
your opinions on this setup ? I *think* that suspending an engine
from the adapter plate is essentially what all the Subaru airplane
folks do.


I'm really pretty excited about the idea of putting a Suby in my car.
And it would be even more cool if it turns out to be affordable.

Please let me know what you think....

[lapuwali]

QUOTE (914turboford @ Oct 5 2005, 10:36 AM)

I'm not saying he should install a Ford 2.3 turbo like I did. It sounds like he is pretty set on a Subaru engine. I don't think he would have to cut the trunk with a Subaru trans. I don't think the Subaru trans are week. I've never heard that. Also, they are easier to find than 914 transmissions. At our local self serve JY there are probably one or two 2wd EJ Subaru transmissions and there have only been 2 teeners there in the last 5 years. Here are some advantages/disadvantages of my setup. I can work on my car. I don't have to lay on the trunk to adjust the points. I don't have to work in an impossibly tights space under the car to adjust the valves. Easy to obtain 250+ hp with 400 not unreasonable. All wear parts obtainable at Kragen. Cheap and easy to find parts. Engine can take 25 psi boost with a stock long block. Center of gravity is both higher and further back. I like the further back CG. I prefer a little oversteer. I have stiff sway bars front and rear and have the car pretty low and I am quite sure I am ahead of 90% of the teeners out there in the handling department. I did cut up my trunk floor and my right coilover tower and reinforced all of this with a nice, light cage. I know my car is stiffer than a cageless teener. But this is about the Subaru conversion. The shift linkage will be about the easiest thing you ever do. It took me literally less than one hour to design and fabricate mine. Engine mounts are very easy as well. Usually one of the easiest parts of any conversion, IMHO. To me the hardest part of an engine conversion is the plumbing. Exhaust, coolant, power steering (NA to you), fuel, etc. In the end, though, you should do it the way you want. It's going to be cool whether you use the Subaru or the teener trans.

A couple of Subaru tuners have complained about the weak transaxle, at least in the era before the WRX was available in the US. The 2.5RS transaxle, for example, was known to break even in the stock application. The 2wd transaxle was intended for the granny market, basically, and doesn't take abuse kindly. It's not likely to be a huge deal, really, but using the Subaru transaxle really just trades one easily solved problem (adapter plate/flywheel) for another, and doesn't seem to gain you much. I think it ends up being a wash, at best. The advantage of the 914 transaxle is you can buy parts rather than fabricate them, which can be a huge advantage for those people who don't have ready access to machine tools or the ability to use them. Something that takes you an hour to do may be completely beyond the ability of many.

QUOTE

I am quite sure I am ahead of 90% of the teeners out there in the handling department.

That's a pretty bold statement.

One of the things I like about the Subaru conversion is that weight distribution isn't affected much over the stock setup. Scott Thatcher's fabulous radiator setup even leaves both trunks unmolested, and ends up with overall weight and distribution of weight that's nearly identical to stock.