You can pretty much flip any axle as long as you adjust the fill and vent.

The 203 is way too big and heavy. I think they are all cast iron aren't they? Weigh 165lb and have a built in diff for full time usage. They are 15" tall.

I'm still thinking about it's placement. It I attach it right after the trans it will be around the knee to feet area so a small unit (D20) would be best. If I move it forward of the feet, then I could use a physically larger unit (205). I've got an idea for a simple torque tube design to mate the T-case to the trans. Kind of like the C5 vette. That way the entire driveline will be bolted together as one and rest on bushings to reduce vibrations.

Using an offset differential, I think as long as the drivers side axle clears the harmonic balancer, then I can keep the rear wheel placement pretty close to stock. I may need to move the wheel back a little, but the exterior should look pretty close to stock.

 

I'm also trying to decide if I should run equal length half shafts or un-equal length. Equal is the accepted design in front wheel drive cars, due to torque steer, but it will cost me more. I think the un-equal should work just fine for a rear setup.

If anyone knows of a good reason for me to have 3 custom axles made instead of 2, I'd like to hear it.

Here's a decent picture if your not clear on what I'm talking about.

 

The 203 is aluminum cast; I have one. Yes it has a diff for full time, but if you are running the front output (the one that faces the same way as the input) then you need the front output to be always engaged, if I understand your diagram. If the gray box is your xfer case, then the RWD output of any case I have ever seen will be non used, as in your setup, it would be facing the now empty engine bay, right?

Now if you figure out your rear end, I would say run a divorced NP205. That way, while you will have to use a small custom shaft between the transmission and the transfer case, you can set that distance to match an existing shaft for the return route back to the rear wheels. Also running divorced will remove a lot of the trans output shaft mismatch issues you would get from a case that was mated to a certain transmission from the factory.

 

I don't mean to hate on you here bro but I just don't see the point to this thread. It's a dreamer project. I'm tired of this photochop junk. I don't mind you dreaming about this and it is interesting but is "advanced engineering" the section for this? It's not the "Advanced photoshop/MS Paint engineering" section is it?

Im think i'll start a thread called "My nitrous fed - jet-powered - mid-engine AWD Trans am". In this thread I plan to do several detailed photochops in which i will place a jet engine over a profile shot of my car. Then hook up 37 NAWZZ systems to it in MS paint.

I will then argue and justify that it CAN be done and DONT HATE. AND its my dream to build this...

 

Your correct about my diagram. The diff, rear output and reduction gears can be removed or cut out of the case to save weight. I just need a strong method of transfering the power 180*. Basically like a poor mans V-Drive.
What is so great about the 203? It's huge for one thing. Is it any better than the Syclone BW 4472 case?

 

If that's what you want to build, then go for it. I would consider an aircraft or jet engine forum, though, as the type of vehicle is rather inconsequintial. I know there are compact jet engines that will fit, but it's not very practical. Oh, and you may want to find out what nitrous oxide would do in that type of engine. I would suggest you check out some turbine engines. That's the best way to get the power to the 4 wheels.

If you start that thread, post a link here. I want to check it out. Thanks for the compliment.

Ps. Also, thank you for telling us what your tired of as well as not minding me "dreaming". I'm sure everyone is relieved to hear this.

 

To get back on topic, I really do admire the efficient packaging of a transaxle with the diff mounted between the engine and trans. So I was mapping out the power flow to see if there was a way to convert a strong and cheap T-56 into a similar design.



As you can see, the T-56 design just does not allow the power to be redirected to the front. The only way to do it would be to route the power externally which is why I was looking at a V-Drive or transfer case.

So the next issue is how to make room for a diff between the LS1 and the T-56. This was tricky, but it is already done on the vettes. The concept is to take one of those torque tubes and shorten it drastically. Sort of like this picture.



Now it may be easier to just make a spacer myself than to use torque tube parts. The trick here is to figure out how to extend the input shaft. I don't know if the input shaft spins on one or two bearings. If it's just one, then I'm kind of screwed. I'll have to figure something out.

You can then mount your beefy diff right between the flywheel and the trans like so:



There you have your poor mans transaxle, except this has a lot more advantages.
It can handle lots of torque
It's easy to change the gearing
It's easy to change the LSD
The whole setup is much cheaper than a Porche transaxle.

The 2 down sides are that it's not a nice neat package which may have trouble fitting some vehicles (not mine) and that it will weigh more. Again, that's not a major problem for me.

With this setup I can run whatever transfer case I want as size is not a concern anymore. I really don't even need a transmission tunnel running in between the seats which is interesting. I can use that space for a fuel tank if I want.



Well, I probably need it to stiffen up the chassis.

 

Why not modify an olds tornado transmission from a 60's FWD car:

Why not use a Porsche rear suspension and transmission?
Several companies install mid engine v8's in the 914 model

 

Not with the original 914 rear equipment + a v8, right?

 

Are you asking me why I chose not to use the TH425?
I don't like automatics for one. The second is it only has 3 speeds. No overdrive sucks.

The reason I didn't use a Porsche trans is due to the high cost.

 

LOL

I find this very interesting and hope you do go through with it. Not alot of people are creative enough to make dreams a reality. Looks like you are one of the few that are.

 

Just an update.

I'm looking for an aluminum LS block and T56 case just for mockup purposes, a complete 90's T-Bird rear suspension, and a C5/C6 torque tube so I can get the whole drivetrain sorted.

What I'm really focused on at the moment is designing the front suspension. I'm converting it to a short spindle design (no more shock towers) and I've narrowed the spindle choices down to a C4 unit. There are 2 different height units that I need to measure personally to see which would be the better choice. The 84-87 are a tad shorter than the 87-96. Then the 84-87 can further be broken down. The 84-85 units have different brake mounts than the 86-87.

I picked up a K-member and lower control arms last week. The new setup will be a hybrid of those parts, plus the C4 spindles and some tubular upper A arms.

One bonus thing I learned is that the vette spindle automatically drops the ride height just like a drop spindle would. That's sweet. :-) It's one less thing I have to design.

 

Remember how I was toying with using an automatic like the mongoose cars a while back?
Well, I'm considering it again. In fact, I'm not sure I want to part out my complete 99 car. I think I can build XTA piece by piece. I can buy a wrecked donor car or just use junkyard parts.

Anyway, using a 4L60-E or 80-E kills a flock of birds with one stone.
1. The cost of a good cable shifter ($500) will pay for a used auto right there.
2. There are already adapters to mate strong, gear driven transfer cases to these transmissions. This is due to lots of Jeepers swapping to these better GM transmissions.
3. There will be less driveline shock compared to a T-56.
4. I've come up with a way to seperate the engine and trans to make room for the differential.
5. Fewer custom parts and less fabrication overall.

Autos aren't as fun, but there is room for improvement. Paddleshift systems are already out there. I can also swap in a 3,000-4,000 rpm stall converter. That would be fun. :-)

The light duty option would be a 4L60-E with a D300 transfer case.
The heavy duty option would be a 4L80-E and a NP 205 case. The down side to the HD option is increased weight.

D300 = 80lbs
NP205=138lbs
Keep in mind these will be lightened once I remove the low range gears and other unnecessary components.

4L60-E = 175lbs
4L80-E = 255lbs

Light duty combo - 255lbs
Heavy duty combo - 395lbs

That's 140lbs more and it all behind the rear axle which is the worst place for it. Do you think the extra weight is worth the much stronger setup?

 

Here's a comparison of the 700R4 (which is close in size to the 4L60E) and the 4L80E. Both are shown with the big dog NP205 transfer case.




I actually like the idea of running the bigger trans. It should mean fewer problems down the road and they are not that expensive used. I see them fro $500-$750 locally.

Now the NP205 case might be a bit more than I need. Maybe the combo of the 4L80E and the Dana/Spicer 300 transfer case would be a good combo. That would only be about 80lbs more than the light duty combo.

 

I also found some good pics of the corvette torque tubes. I finally understand how they work, both automatic and manual versions.

The automatic has an extra plate bolted to the flywheel onto which bolts a splined coupler. On the other end is a simple flexplate that bolts to the converter on one side and that plate then bolts to the shaft coming out of the torque tube.

Here are some front pics of the Auto tube.

Flexplate/flywheel


Coupler


Both pieces together


Then on the front of the torque tube there is a splined input shaft very much like the Manual version, just without the hydraulic throwout bearing. It may actually be identical, but I don't know for sure.

 

The converter end looks like this:







This 3 sided converter plate mounts to a short shaft with 2 beaaring supports and either slides into the torque tube or bolts onto it. It has 8 bolt holes on one end and a 3 point mount on the other for a rubber bushing. Rubber bushings are used on both ends of the internal driveshaft.

Converter end


Engine end


This shows the 2 different looking styles at the converter end. The newer left style slides in and is held with a big snap ring. The one on the right is the earlier style and bolts into place.



Here's a diagram. Notice it has 2 bearings. I think the front only uses one bearing, but the shaft goes all the way into the crank mounted pilot bushing. So maybe that's what keeps the front shaft spinning true.



Here's the complete internal setup.

 

So far I've come up with 2 ways to seperate the engine and trans enough for me to get a driveshaft through in front of the converter.

Here are the parts of Design 1:


Then you move them all close together. I basically removed the driveshaft and one rubber bushing to make a super short torque tube.


It would look pretty close to this. I have plenty of room to mount the differential into place, but the transfer case may stick out of the back of the car. That's not good.


Here's Design 2. This one is a shorter design. It basically uses the flexplate on the engine side and a converter plate on the converter and both plates use the same type coupler. I just have a long splined shaft made so that they can be bolted together. The one flaw is that I may need to have a support bearing in there for the converter.


I'll think of something.

 

Awesome..Keep it up...

 

hmmmmm looks kinda like a G50!

Chris.

 

The Porsche G50 transaxle?
I don't see it.