markbsae

What is depicted in the line drawing is not a C5 Transmission. That is an F-body or GTO style front mount which is whay I was saying one of those would work without a massive conversion as where you will have to change from the front bearing plate forward and the tailhousing back. The shifter (if manual) would be WAY more straightforward also since the rail for the C5 goes out through the front bearing plate instead of intot he tail housing. Also note picture 6 shows the V-drive. The two 6 bolt patterns would be easy to face, bore and make a power tap for the front diff.

BigPines

I don't know for sure what is represented in the drawing but I know he used a C5 manual tranny (Borg Warner T-56) in his build. That is what it looks like to me in the drawing. It probably just looks different because the torque tube has been eliminated which is exactly what I have been saying I wanted to do. I am planning to go automatic so I won't have to worry about the shifter or linkage.

Yes, we could probably get another shaft off the back side of the V-Drive but there would be no give between the front/rear driveshafts if I did that. It would basically be a 50/50 4WD 4Hi-locked configuration. This isn't great for making turns on dry pavement. This is the reason why I rejected welding the spiders in a potential center diff. I feel like I must be missing something here. Am I? Maybe I could pull a driveshaft off the front of the V-Drive and then attach a Torsen center diff from an Audi/VW to the front diff to deal with the problem? Like I said before, I need to look into how those work to figure out if I could use one. If anyone know, I'm all ears.

Mike

markbsae

It is not a C5 transmission. It is an Fbody or GTO.

This is a C5 auto transaxle:
http://forums.corvetteforum.com/atta...ion-tranny.jpg

This is a C5 manual transaxle :
http://www.web-cars.com/images/vette_img/DSC_2704_a.jpg

This is what he used:
http://www.malwoodauto.com.au/images..._1_(Small).jpg

BigPines

This is probably just my mistake. Apparently, the C5 manual tranny is the Tremec T56 (see attached). The images you are showing for the C5 trannys still have the torque tube and/or rear diff bolted to them. That is why they look different right? I mean these aren't really transaxles in the truest sense of the word since they are really separate parts just bolted together.

The thing I am confused about is the bell-housing definitely looks different on your T56 image but it still says it is a Tremec T56. So they must have made different versions or can you just add that piece on? The input/output shafts may have to be changed too? Maybe what you are saying is it may be easier to get a tranny already set up in that configuration.

Sorry for my ignorance here.

markbsae

You are correct, the C5 T56 is basically the main case of a tremec T56 with a different front bearing plate and bellhousing (to accomodate the torque tube), different input shaft (to couple with the drive shaft), different output shaft (to spline couple with the pinion shaft), different tail shaft (to bolt directly to the diff). These are all shared traits with the 4L60E auto also. Thats why my previous post has my advice of trading your C5 transaxle for an Fbody or GTO 4L60 if you want an auto. It is way more straight forward than converting the C5.

BigPines

Thanks markbsae. Sorry I was so slow to pick up on that. Good advice. Sounds like it is definitely worth going that route.

madskater5

I don't really have anything smart to add to this, but it did remind me of two things I've seen before:

If you haven't found it yet (though I have a feeling you may have) here is an awesome story about a guy who built a Countach in his basement:
http://kiengineering.com/The_Bull.php

As you go through with this, please make it look better than this Aventador built off of a GTO/Monaro

phongshader

Looks like this has been idle for a while. I did a bunch of research on this about a year ago, http://www.locostusa.com/forums/view...hp?f=53&t=9269. I found 2 solutions for the torque split tcase issue, both are Land Rover tcases but both have a 50/50 split.
The LT230 found on Rovers before 2002 is a gear driven tcase with an open diff but a ATB (torsen) dif can replace the open diff. The problem is it's HUGE and has a passenger side drop and it has an oddball input shaft so an adapter/intermediate shaft has to be made...very expensive, $600-$1k but the tcases themselves are cheap, you can pick them up for $150 or less all day long. The other Rover tcase is the NV225 which is chain driven, torsen diff, 50/50 split. The downside is they aren't cheap, the cheapest one I found on Ebay was around $600 but they're more likely to go for $1-4k and there are no replacement parts. The transmission that this tcase sits behind in the rover is a GM 5l40e that I know has a 27 spline output shaft and I'm hoping that the output shaft has the standard GM 27 spline shaft, same as the t5, t56, etc. What that means is all that is needed is an adapter plate, no intermediate shafts between the trans and tcase. With the 50/50 split you could now go with the Lambo mid engine layout without the added complexity of v drives and a lot of extra driveshafts (and added weight) For the rear diff you could use a reverse cut high pinion front diff from a Ford 8.8, Toyota 7.5, or if you want a lot of strength (and weight) Ford9" and flip it around and upside down and you'll have a low pinion rear dif running on the drive side of the gears. The front dif is a little harder, you'll probably have to run a rear dif upside down which causes 2 problems, one your driveshaft now runs high up into the chassis and will probably have a high driveshaft angle and 2 running a dif upside down that's not designed to do so can cause oiling problems..nothing an oil pump can't fix just more complexity and weight. Another option is to run a rear engine Porsche front diff...high$ but simple. Don't know what r&p gear ratios Porsche diffs come with or if you could find matching ratios for your rear Ford, Toyota, GM reverse cut rear diff. Any how hopefully this is some food for thought.

BrockZ06

How is the project coming along? I began reading this thread and recall the passion and motivation of the OP'er and his desire to undertake such a project "against the odds" and was hopeful he would pursue it.

Any word on how BigPines is coming along with the AWD Lamborghini project? I would be interested to know how far along he and his brother are almost a year into it?

Mike

GSAWYERS

A couple solutions to an awd setup are available but would be relatively expensive.
You could adapt the awd Porsche 911 Turbo to an LS if you put the engine in the rear, facing backwards. Some of these drivetrains are computer controlled so you would have to research before purchase.
The next level of cost would be the Gallardo/Audi R8 drivetrain. These are more than strong(2000+hp capable with mods). The downfall is the Gallardo/R8 front differential is sketchy from ~1200hp and up. The front diff is usually removed if you want to make big boy power.
Another option would be to use the Murcialago drivetrain. It is battleship strong if you address the weak clutch Lamborghini uses. The front diff is still a problem above 1200hp as it will eventually frag.
Of the 2 Lamborghini drivetrains I think the Murci would be the easiest to adapt to an LS. There would be some engineering hurdles. The e-shift trans can be converted to manual shift relatively easily if you can't find a manual trans(e-shift is generally more common).
Unfortunately, unless you score an intact Murci or Gallardo/R8 drivetrain at an incredible price your $80k budget is going to be blown through. Any part for a Lamborghini has an "*******" tax attached to it. The parts to convert an LP640 trans from e-shift to manual was around $28k. The 4 inch long shifter(without ****) was over $4k. if you hit the Powerball or have real money I'd be happy to figure out how to adapt an LS to one. At that point it would be cheaper to just buy a used Murci.
The Porsche Turbo setup would be less expensive and probably a more realistic solution. Expensive is a relative term when you're dealing with exotics. A mid engine LS with a Porsche 930/935 transaxle would be way more cost effective, much simpler and the parts to do it exist. I'm not trying to dissuade you from doing an awd car, just would like to point out some issues with breaking new ground. If you don't have serious R&D and fabrication skills along with real money the chances of building an awd mid engine supercar without using at least a proven platform is going to be tough. Getting the f/r torque split and balance right is going to be crucial if you want to corner effectively on the throttle. A 10% difference in torque split can be the difference between an understeering pig and a balanced car at high speed. If you want to drive the car easy around corners, an awd setup could be crudely put together and made to work ok. Realistically getting it right would be either a stroke of luck or an incredible accomplishment. Yes it could be done but honestly, to build to a supercar level you are going to need more than a truck t-case and some fab work. If you just have to have an awd Murci replica that works at Camry speeds you should be able to pull it off. Getting it right is going to be tough and expensive. BTW, with the weight of the engine and transaxle over Murci sized tires, awd isn't necessary. You can plant 1600 to 2000+hp pretty effectively on drag radials, it's done more than most people realize. There are dozens of 1500+hp rwd tt Gallardo's out there that are frighteningly fast on drag radials or just good street tires. If you have the opportunity, drive an awd Gallardo and a rwd Gallardo or an F430 or a 458 Italia, the difference in steering feel and precision is noticeable. I really think Lamborghini puts awd in their cars to be different from Ferarriand to keep bad drivers from killing themselves.
Personally, if I wanted an awd exotic that looked like a Lamborghini, I'd buy a Gallardo(preferably a 5.2 liter) and enjoy the car. If you decide to build the car, good luck. I hope it turns out the way you want it. If you are in the tax bracket for a used Lamborghini, pm me, I'll turn you on to some guys that will take care of you.

DrBluntson Honeydube

It's a little late for this post but genius doesn't care about timing. Audi chassis - cut away what you don't need put an LS in the back pointing foward and run a driveshaft among one side transaxle (audi o1e) and bolt a v- drive (probably custom) going to the front of it to correct rotation. Build your own v- drive. Use junkyard Kenworth trans gears for strength and offset. Punch a hole in the bellbousing to pass the driveshaft through or cut off one side to get it closer to the center line. Added bonus - you can swap the final drive if you grab multiple gear sets (5th 6th?) . On a final note - the amount of "CAN'T" ON THIS site is astounding. Art Arfons used a surplus military turbine and a dump truck front axle to go 600mph in the mid 60's. No CAD/CAM , no FEA no 3d printer no super computers in your hand. Just old fashioned 'MERICAN can do.

G Atsma

Arfons slapped a jet engine on the back of a rolling chassis and went fast. What you are saying indicates pure ignorance, as it appears you have no knowledge of how things actually are with auto parts. Arfons KNEW what he was doing. You don't.

DrBluntson Honeydube

We have a winner. To stupid to see when I bait you in? Now you make some bold assumptions of my knowledge base . Allow me to do the same with you. Only difference is unlike you I have the brains to be accurate. You probably have built plenty of things and have a decent mechanical understanding but all of it was based on what other people have already figured out. I stand by what I wrote in my previous post. Tear it apart. That is a challenge. You won't for the same reason you assume I don't know what I'm talking about - you are to arrogant and ignorant to think outside the box. So do me a favour close the lid and kept quiet while the free thinking people are moving the ball foward you human anchor. Your move goof.

G Atsma

I am known for thinking outside the box, but I am not as conceited about it as you. So far you have generalized about all you have said, no specifics. There is something to be said about people who debase others to elevate their own self image. It's just not very nice, so I won't say it here. But so far all you have spewed is a lot of self-promoting hot air.

DrBluntson Honeydube

"There is something to be said about people who debase others to elevate their own self image" - Seriously that is your response? Read your first response to me and tell that's not exactly what you did. Oh sweet irony. As for me being conceited I would have had to stated somewhere that I am without fault. I have many strengths but I am far from infallible. As for me generalizing and not giving specifics - about what? As far as I can tell this has never been done before. Again tear my idea apart instead of trashing me. I would love one of the many people on this site that know way more than I do about things of this nature to explain why this might be a bad idea. But I'm just not going to sit idley by as you or anyone else takes pot shots at me.

G Atsma

OK, see how many people align with your way of thinking. I hope you are VERY patient.
BTW, potshots are akin to shots in the dark. I target all my shots. As far as tearing your idea apart, come up with a SPECIFIC idea so that may be possible. Your ideas for a mid-engine car are all just speculation instead of concrete ideas. Kenworth gears?? Kenworth does not even manufacture gearboxes. Punch a hole in the bell housing to pass a shaft through?? No room with a flywheel hogging all the space. Here is where I knew you do not know what you are talking about. That thought still stands.

DrBluntson Honeydube

Finally a question. Of course it's all speculation but not out of the realm of reasonability. Ok forget I said Kenworth and think transport truck(TT) gears. My thoughts are that the gears might be large enough to get the input for the driveshaft far enough over not to interfere with the side of the transaxle case. Should be easy and cheap to source from a wrecker. Strong. Helical cut (I know not all of them) to keep it quiet. Input shaft from TT is large. Maybe large enough that custom shaft that gear would sit on could be machined to slide over the input shaft of the transaxle. Flywheel and clutch would still be on the motor which leaves the bellhousing wide open to fill it with my crazy ideas. Getting a better idea that I might be onto something?

G Atsma

Sure seems like you want to do some complex engineering for something that's been done. Lamborghini situated the engine and trans backward to normal orientation, put spur gears on the end of the tranny, then ran a shaft all the way back thru the tranny and engine to a diff immediately behind the engine. The tailshaft of the tranny actually was right below the shifter.
Other than this layout, shorten the C5 or C6 Vette's driveshaft and close-couple the engine and tranny to get a rather lengthy setup with the engine a bit forward of the rear axle.
The only feasible alternative is to just use a transaxle like a Porsche unit and flip it around for midengine use.
With all the above possibilities, there is no reason to overthink this whole thing.

DrBluntson Honeydube

Have you forgotten that the point of this was mid engine awd? Lamborghini trans cost more the most people's whole car. I've read 30k just for the trans. No diffs, no driveshaft or axles. The C5 transaxle has the diff at the rear. One guy built a tube frame track car using C5 suspension and drivetrain converted to mid engine with no torque tube and it was still a mile long. You would be sitting on the engine. The Porsche G64 awd transaxle flipped would have the front diff output at the very back of the car and would be reverse rotation you would still have to have a transfercase off the back of the car and 10-12 feet of driveshaft to get it to the front (I have seen this with a mid engine awd audi setup on a grass racer). Now if you had the money take your O1E transaxle to someone with a faro arm digitize it and have www.scsgearbox.com whip something up for you quick but we're trying to speculate this on the cheap. That's why I said grab an audi chassis and cut away what you don't need. By just using the Audi pan and my transfer box idea you have all the suspension, transaxle, driveshaft, cv axles and all the mounts already done for you. The only problem I see is the shocks mount on top of the upper control arms (A4 and A6) and you would have to go to pushrod and lay the coilovers on there side to clear the Murcielagos low hood line. This is speculation I know. Until you get under the car with a tape measure who knows.

G Atsma

There is no strength in the Audi pan alone. A unibody depends on the whole structure for strength. It's not like the old VW pan that could work on its own without a "main" body. What you are dreaming up will use various parts from a myriad of sources, but making it all work WILL cost plenty! You and I are not engineers, but it would take one to make your ideas work PROPERLY. You would be better off building a tube chassis to do what you want, and use a regular tranny behind the engine, with both turned around, like the Countach, as I described in a previous post. Any transfer box would then go behind(ahead?) of this setup. This is the most doable setup you could do with resources available.