Mid Engine 944 Audi V8

So I just bought a 1987 944S and a 1999 Audi 4.2 V8.
I want to put the V8 in the back behind the driver.
My research indicates the 944S transaxle will bolt up directly to the 4.2 v8.
However looking at the rear suspension, the torsion bar tube is directly in from of the transaxle and can't be modified as the torsion bars go right there. What I was thinking was to reverse the suspension, so the torsion bars and suspension pivots are BEHIND the transaxle, basically flip it around.
I understand I need something to mount it back there, but my question is really is there any suspension geometry theory problem with having the swing arms swing from the back?

Mod the torsion tube like the Vette transaxle swap guys are doing. Run bigger springs.

xschop wrote:Mod the torsion tube like the Vette transaxle swap guys are doing. Run bigger springs.

Where can I find info on this "Vette transaxle swap" ?

nimblemotorsports wrote: is there any suspension geometry theory problem with having the swing arms swing from the back?

I'm not a guru on suspension geometry but I think it's asking for trouble to have the swing arms trying to pole vault the rear end of the vehicle as the wheels encounter bumps.

I am looking forward to following your project no matter what you do!

Why is it trouble?   I do see that with the pivot in front, the wheels 'pull' on the suspension arm, with the pivot in back the arm is 'pushed'.   I have never seen a car with rear pivot suspension, but I think this is because the structure to attach it is best placed in the middle where there is already structure to keep the car from bending in half, so putting more in the rear would just add weight.  I will pay the extra weight in exchange for not having to use/buy a different rear suspension that the existing 944 parts.  

I'm not even sure what other parts I can use for a mid-engine rear suspension that are cheap and simple (I had a boxster, that setup would be very difficult to transplant).

sparkydog wrote:

nimblemotorsports wrote: is there any suspension geometry theory problem with having the swing arms swing from the back?

I'm not a guru on suspension geometry but I think it's asking for trouble to have the swing arms trying to pole vault the rear end of the vehicle as the wheels encounter bumps.

I am looking forward to following your project no matter what you do!

you would be better off to remove the torsion bars and run coil overs, then cut the torsion tube. no matter what, your going to have to do a lot of structural work to the car to do what your proposing.

the audi engine may use the same bellhousing bolt pattern as the 944 transaxle, but the input shaft isnt going to work. the input shaft on the 944 is longer and doesnt have a pilot machined into it. you would have to swap in an audi transaxle or change the mainshaft.

I think the inner control arm pivot is also going to be in the way of the engine, so just deleting the torsion bar doesn't solve the problem.  I could perhaps remove the inner pivot and add another lateral location arm somewhere else.  No doubt structural work needed, in fact, a LOT of work needed, this is no bolt-in swap.  

I do have two other audi automatic transaxles that came with the engine, but I was hoping to keep the 5-speed, machining the shaft isn't a big issue.

However, looks like a flywheel for a v8 audi will cost more than the car itself, so might have to live with the automatic (tiptronic?).  Any ideas on how to get a flywheel?  Get one filled and redrilled for the 10 bolt of the 4.2?  That must cost under the $500 to $1500 people asking for the hen's tooth 4.2 flywheel.

sharkey wrote:you would be better off to remove the torsion bars and run coil overs, then cut the torsion tube. no matter what, your going to have to do a lot of structural work to the car to do what your proposing.

the audi engine may use the same bellhousing bolt pattern as the 944 transaxle, but the input shaft isnt going to work. the input shaft on the 944 is longer and doesnt have a pilot machined into it. you would have to swap in an audi transaxle or change the mainshaft.

Thinking a little more about your proposal to mount the 944 torsion assy and swing arms from the rear of the car - I DO feel qualified to comment about hacking up the rear of a 944 and other related issues. Here's some things to consider that come to my mind:

You'll loose the spare tire well and probably need to use a different fuel tank arrangement.

I think the width of the torsion housing is wider than the area between the fender wells aft of the axle centerline - so if I'm right then the ends of the torsion housing may be close to protruding out beyond the exterior sheet metal.

Brake caliper mounts will be in a different quadrant of the wheel and you'll just need to think about how they transfer load into the swingarm casting under braking.

Upper shock mount location will change and more fab involved to create a new location.

I haven't cut into the frame rails aft of the shock mounts but I suspect they have thinner walls - Porsche has multiple layers of stampings inside the frame as needed to deal with loads. As you mentioned there isn't much loading in the back area so you'll probably need to add bracing/gussets as you go.

Any suggestions on how/where to sell the 944S (16v) engine? Local craigslist has been zero.

Looks like the VR6 flywheel will work with some minor plug/drill work.

nimblemotorsports wrote:Any suggestions on how/where to sell the 944S (16v) engine?  Local craigslist has been zero.

Looks like the VR6 flywheel will work with some minor plug/drill work.  

If you have Facebook, check out a group called 'Porsche Parts Group 944 951 968'

The link is [You must be registered and logged in to see this link.]

Let me know if that link doesn't work, but there is about 3,200 people in that group. I have sold numerous parts in a short amount of time.