By Rick M 333 Date 2009-11-09 01:31
Ok, my SR is long gone to a happy home elsewhere so I can turn my attention to my other project in house. It has, at it's core, a vintage Ford V6 coupled to an Audi 100LS transaxle driving hybrid (read: welded) driveshafts to what is essentially a Corvair rear subframe... highly modified. I have an idea of where I want this project to go, and I'm not entirely sure I want to use the Audi transaxle. The engine is definately going - a 400 pound lump that's been sitting for 30 years. Anyway... the entire drivetrain in mid-engine. For those that don't know the Audi story, it's essentially a VW transaxle (automatic) that was used in quite a few VW's and Audi cars through the early '70's - FWD configuration, too! My question is pertaining to the 'Vair automatics: I'd like to keep the car an automatic, as well as mid-engine since it's already designed that way. On Clark's site they show the big V8 conversions with the front end of the transaxle modified to fit the bellhousing of the motor. The "bellhousing" end of the transaxle is blanked off and used as a support structure. If the 'Vair engine spun the wrong way and was mounted at the rear, why wouldn't turning the transaxle 180 degrees (bellhousing forward) work for a normal rotation motor, like a small block Chevy for instance? Am I missing something so simple I don't see it?
By Jay H (X-20) (ManxVair CC) Date 2009-11-09 02:16
Rick, From what I understand about the Corvair automatic, it was also used (or maybe that is: developed for but not used?) in the Pontiac Tempest, or something to that effect, so I think you are correct.
I do know that the Turbo Hydramatic 350 was adaptable to the Corvair. I googled it and came up with this: http://en.wikipedia.org/wiki/Turbo_Hydramatic#THM350
Not that that helps, but I figured I would add more confusion, LOL.
By Rick M 333 Date 2009-11-09 02:37
Thanks, Jay. Just what I need... But yeah, I had read that, too, about the Tempest. If I could swap one 180 degrees, then most of my issues are solved... but I think I'm going to have to mount the tranny the "normal" Corvair way with the engine ahead of the actual Powerglide head... and I just don't have that kind of room!
By Jeff GS Date 2009-11-09 12:34
Hey Rick - I'm guessing you already know this, but there were 2 "conversions" for the 'Vair transaxle to convert it for mid-engine. The Crown conversion is the one you are describing - they just "drove" the trans from the other end - opposite from where the normal Corvair engine was driving it. I believe this solved the rotation issue, as the trans was still spinning the correct direction and engine could be built "normal" V8 rotation too. The drawback was the differential is at the tail of the trans.
The Kelmark adapter swapped the trans around (as it sounds like you want to do) and used a longer input shaft. This solves the bellhousing to trans output distance issue (keeping the diff between engine and trans) but it does spin the trans the wrong direction. These had the weak points of driving the R&P the wrong direction and the longer input shaft breaking and I believe it's now NLA.
I think the Audi trans is probably the best way to go? It's already spinning the right direction for mid-layout, and strong enough to take a small V8. I know one of the 914 groups is working with the Boxter trans to adapt it to the LS series V8 engines, as well as the Porsche 6 and 914 motors. Lastly there is the Subaru auto - which I've read can absorb lots of HP when properly built and makes a great mid-engine setup. Just might have trouble adapting another engine to it?
More confusion to add.......
By Rick M 333 Date 2009-11-09 22:18
Thanks Jeff. I couldn't quite "get" the difference between the Kelmark and the Crown adaptations until I actually saw the photo of the Crown setup. Weird to see that big flat plate on the end!
I did find someone local to go over the existing Audi trans... at some cost, though. I also found in my searchings that the early Audi 5000 trannies are the rage for the Lambo guys for the mid engine setup. I have a line on a rebuilt for cheap, but shipping is going to kill me. If I can swing it and get it in house, I'll post photos of it compared to a regular VW trans. Methinks it's a little shorter, so that might be of some use to guys that want to do a mid engine car!
By Jeff GS Date 2009-11-10 01:54
The Audi 5000 box appears to be very popular, so much so that the cost of used boxes was driven up. The stock gearing isn't great for a V8 car, but a smaller higher revving engine it should be good. They make a special ring and pinion gear for it with lower ratio, but it's lots'a $$$!
Sounds like your "mystery" car is already set up for it - why change? Even some of the GT40 clones use the 5000 trans - I saw an RCR version at Carlisle last year that had one with a 302 Ford pushing it. They said it was a demonstrator for a "moderately powered" and priced option for a '40. Seeing how most of their cars are set up for much more expensive transaxles (in the $8-10K range - yikes!), the Audi seemed like a neat idea, even if a "built" one was in the $5K range.
Any consideration of going transverse? Lots more transaxle/engine options available for that configuration.
By Rick M 333 Date 2009-11-10 03:19
I had thought about that, Jeff. It still isn't totally out of the question, but, like everything else, budget is an issue. I also kinda want to keep the car close to what the original builder had intended the car to be 'back in the day'. He's still around and he had never completed the build past the 'start and run' phase. So it might be cool to complete it and shoot him some photos. But then, he could care less, too
My 'sorta' game plan is to at least have the running, if not finished, car there at Carlisle this coming year. But if business doesn't pick up, that may not happen
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