So I managed to get a great deal on a complete corvette drivetrain from a 2001 corvette, I was planning on doing the LS1 swap anyways and after some discussion with my friend and fabricator Keith Zimbauer from ZFab here in Santa Clara we decided that it was very plausible to install the torque tube and complete transaxle assembly from the C5, at this point I think everyone has only speculated at doing this (correct me if I am wrong), I know there are several C4 IRS swaps done which was my motivation to attempt this. At this point I have all of the parts for an automatic transaxle assembly, I intend on going with a 6 speed instead, so I am working on selling the auto to buy a six speed and associated parts from my friend. Yesterday I pulled the stock 10 bolt and all of the suspension pieces out of the car so we could get an overall feel for the location and problem areas that we are likely to encounter, initial impressions are that the overall width is going to be perfect or very close to perfect, not too sure yet if the gas tank will be able to stay. The passenger side shock on the transaxle hits the panhard bar bracket when I try to jack the assembly up, so hopefully this weekend I will get a chance to remove the shocks and lift the rear end up farther under the car. Here are some initial pictures, showing the overall width, I will work on some more detailed photos after I get the shocks out of the way and get the thing jacked up further.

 

Dude, you're nuts, but in a good way! I want to see more of this.... did you see the other thread with the guy installing the front end of a z06 in his 3rd gen?

Subscribing.

 

agreed - the fab work will be insane, but would very much like to see someone pull it off. good luck with the swap!

 

Andrew91GT, thanks, and yes I did see the front end swap which looks very cool, was kind of figuring the guy would do the rear as well, but it sounded like he was going to stay 10 bolt for now.

1ADan, definitely going to be a challenge no doubt about that, fortunately my friend is an awesome fabricator so I cant wait to see what he cooks up. I am not accustomed to not doing stuff on my car myself so I am going to be pitching in as much as possible on the build, so I should have lots of pictures and details.

We are thinking at this point that we will start about 2-3 months from now since he is finishing up a couple of projects that are taking up his entire shop. This gives me some time to get the Spohn Tubular K Member ordered and get the engine installed in the car so we can start figuring out how much we will need to shorten the torque tube. At any rate much more to follow!

 

Well you definately need to keep us posted. I have thought about this exact idea on a couple occasions, rather than swapping to a solid rear since I want to do road racing and autoX.

 

Hi White 89' I definitely plan on documenting this whole process as best I can so stay tuned!

 

more postings please!!!

 

This is something I've wanted to do since I first heard about the transaxle setup. Can't wait to hear more. Good luck!

 

please make this happen

 

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that just looks soooo sexy...

 

OOOOHhhh!!! YEAH! I can get these transaxle setups for cheap all day long!!! (They are currently only good for c-5/c-6 vettes and most vette owners are picky enough to not want a "Used" trans!) Supply: Good. Demand: LOW! I really hope this works! I might just do it myself! Good luck and tell your friend to keep good notes; he might be able to make some really good money if he could create a "Kit"!

 

I'm curious.....

You mentioned the other Vette front suspension swap & you were surprised he didn't put the IRS in.

So I'm wondering why your doing the IRS but not the front suspension swap with it?

 

Hi Stephen, thats a thought, just need to locate the vette front end.
Quick update, had a meeting with my fabricator friend Keith last night, and looks like we are going to be getting the car over to the shop sometime in March, my old set up (LT1 and six speed) are out of the car and sold I am starting to work on the LS1, going to do a cam swap for now to spice it up some. Anyways, I will make sure to keep this thread updated with lots of information and pictures as we get going.

 

Quick update, we decided it might be easier if we could get a hold of the rear frame sections that have the mounting pads for the rear end from a C5, so I went looking and found a candidate yesterday. We are going on Sunday to cut those pieces out of the frame of the C5, I will post some pictures of that this weekend. At any rate, I am hopeful that the car will make it to the shop in the next month or so, depending on when another project at the shop gets wrapped up.

 

Very cool! I was just wondering what happened to you...

 

Awesome, I can't wait to see this as it progresses

 

This looks sick. Subscribed!

 

I was going to suggest just that. It will make it way easier!

 

It was cool when 2nd gen guys were doing it, though they had a much easier time of it, but why most went the step farther n grafted in the Vette taillights so folks new it wasn't a plain jane and just a few hr engine n trans swap, like it was then.


Now the 3rd gen guys just gotta step it up and go that extra mile, anyone can own a Vette , but how many got a Camvette???

 

Quick Update, the weather has not been cooperating with me lately, anytime I am free it is raining. At any rate we still need to go over to the donor car and cut those frame sections out, just havent felt like lying in puddles to get it done. As soon as we do I will post up some pictures!

 

Is the Z06 the only vette with the aluminum frame right? It would be sweet to make an aluminum frame that bolts onto the stock 3rd gen.

Someone else tried to stick a corvette IRS in his camaro... he got torn apart and then ended up failing i believe and left the project. Hope you follow through!

 

looking forward to watch this project progress!

 

Yeah, the zo6 and ZR-1 are the only vettes with an aluminum frame. The standard vette might be the better donor as the steel can be welded right to the 3rdgen chassis.

 

customblackbird and drknow90rs_ss@y, yes very good point, the car we are cutting up is a standard vette so we should be able to graft those frame sections into the third gen frame a little bit easier. customblackbird, I have seen a few folks who have sucessfully put in the C4 IRS on TGO and they were my inspiration to attempt the C5 IRS, I definitely don't claim to have the skills for this project myself I think the old adage of anything is possible it just depends on how much money your willing to spend applies for this one LOL!!

 

well good luck! I still vote that you make it all out of aluminum but costs will surely rise as well as difficulty.

Can you weigh the IRS setup complete? That thing has got to weigh a good bit (i understand its alot of aluminum) however it looks bulky (prob just looks that way with all the IRS stuff) which is why i ask. My ford 8.8 is by no means light ( not that much more than my stock 9bolt) but i can pick it up myself and move it around fully dressed.

Also depending on your power what are the power capabilities of the rear? my experience is with older vettes 68-78 and the halfshafts on those rears are a weak link.

 

Wouldn't be bad, the rear end it to light stock, long as the F/R weight ration is good.........

 

I do know it weighs a bit, but remember, its not just the rear end and suspension, but also the transmission. I bet it weighs less than the factory 9 or 10 bolt, the 700r4, driveshaft,torque arm, lower control arms, springs and shocks. Plus, some of that weight is being moved to the back! The vette has a near-50/50 weight distribution. This car will probably be around 60/40, maybe better! Not to mention, driveline vibration will be a thing of the past! I'm anxious to see this done! To hell with the house payment! Throw money at it! LOL, J/K!

 

It should be closer to 53/47 or better when you're done. The stock third gens are around 59/41 or so.

 

I will try to weigh the rear end if I can, I am trying to think about how too do that. I do know that with the transmission removed it feels similiar in weight to a 10 bolt, thats just me judging it by my efforts to move it around my garage and what not. It's funny that you mention building an entire aluminum frame because my buddy was making the same suggestion until we found the corvette donor car for the frame.

 

On another quick note, I ordered my F body motor mount bushings and clamshells and adaptor motor mounts from spohn today, so once those arrive I can drop the engine and torque tube in the car and then we can get it over to the shop!!!!

 

I just wanted to let you know that i have the energy suspension poly motor mount bushings (clamsehell style) and they are the worse! I mean they work ok but trying to get a 1/2 DIA grade 8 bolt through it is a pain in the A$$! Im using 1/2" grade 8 bc im putting in a big block, and they took my motor mount bolts when they stole my engine/trans.

I would love to get the UMI solid mounts! but getting the motor mount bolts out of the kmember is not fun esp bc i have to drop the Aarms which means hello coil springs and forget getting the Aarm holes with poly bushings to line up with the coil spring in the pocket lol.

EDIT: i would go solid mounts and poly trans mounts, understood that you would need to weld mounts to the car for the trans at the rear. I would use poly there if you can.

 

customblackbird, I hear ya on those things, I put them in my standard motor mounts and they were a big enough pain in my rear.. I ordered up the standard f Body ones, I find that after having the solids, and the poly that I am getting to old for all of the vibrations and what not. I hear ya on pulling the whole front end apart to change them out too, I've done that so many times now I dread having to do it.....

 

I dont know... My iron-block/aluminum headed LS motor puts my RS around 3,300 lbs and I think I was still at 60/40 or so. I have access to a scale, I think I will weigh the IROC (Mostly stock) this weekend, if I can. It'll at least get us a stock, ballpark figure...

 

So quick update, I received my motor mounts from Spohn and as usual they are great quality! I picked up a bare LS block for mock up, I figured this would be easier to work around then putting my entire engine in the car. At any rate I should be putting the block and the torque tube in the car this weekend. Then I just need to coordinate getting it over to the shop, my friend who is doing the fabricating cut the frame sections from the vette for me already so we are good to go there. So stay tuned, more to follow. I am looking for some input as well, I am considering putting in a simple roll cage, I am thinking a 10 point minus the dash bar and putting in removable door bars. Anybody have input on roll cages in these cars, like them or hate them? I am mainly looking at chassis stiffness first and safety second. I do not plan on going to the strip with the car at all...

 

Cages help in these cars. I would go 8-point if you arent actually racing it. The problem if you have door bars is that they almost always keep the door from shutting unless you ditch the armrests. You could probably have new door bars fabricated that bend for the armrests.. Andrew91GT had some fabbed that look like they would work.

 

i have a Competition engineering 8pt roll bar in my bird. I think they help alot, esp when you build them to tie into strongest parts of the car, or tie them into some custom SFC (this being the best route). When planning for a roll bar/cage then you should also think about SFC as they should mate together in some way to acheive max stiffness.

The 8pt roll bar from CEE was alright, no real issues with it (roll bars are extrememly simple and the only part thats different is the hoop). I will state that the main hoop in the CEE kit had to be pulled in slightly (not much) to get the hoops base to lay where i wanted it. Took maybe 10min with a cumbalong to squeeze it in, then Tack welded it in place.

Door bars will be your next adventure, they mostly will not clear stock door arm rests, but if you get custom bent door bars you might be good. Or you could ditch the stock door panels and go aluminum (much more bad A$$ in my book and thats what I did). Also the door bar will be your arm rest. Then you have swing out kits... most will say that swing out kits are bull$hit and they the destroy the integrety of the roll bar. I welded my door bars in first and then tried to get in my car lol... not happening! Im only 6'1" too. In order for me to enjoy the car and drive it on the street i needed swing out kits. I put CEE swing out kits on, they work and they are certified to 9.99 seconds i believe. There are a few other brands of swing out kits, SW race cars has a set, CEE, But I LOVE THESE! and would have went with these if i knew about them! http://www.bearsperformanceproducts....ges/S-2246.jpg
http://image.popularhotrodding.com/f...ng_out_kit.jpg
these are the CEE ones
http://chassisengineering.com/products/1456-2.jpg

When you fab it all up make sure it comforms to NHRA rules or basically your just adding weight. Now the difference between 10pt and 8pt is no big deal unless your never going to run fast enough to get to need the 10pt, if your not planning on going faster then 9.99s then dont put the 10pt ( i cant remember if the 8pt is good for 9.99 or 8.99 sec). these roll bars are heavy, my 8pt weighed in at 110lbs with floor plates and everything. So consider how you want to run the car and how fast and then consider the weight of the tubing etc.

Roll bar kits i would look at are, CEE, jegster, SWrace cars (i would try them since i love there products and great people).

 

Thanks for the input guys:
Customblackbird, great thoughts, thanks so much. Part of the reason for the roll cage idea is that I did the Spohn SFC's on the car and it made a super big difference however I still notice some chassis flex, length wise, when jacking up the car, so I want to stiffen the chassis to help with that if I can, and add some more safety. I also think that since the Spohn SFC's are roll bar tube, I could possibly tie the cage into the SFC's which I think would be very cool!

 

it would be hard to connect the roll bar to the SFC directly... depending on the placement of the rear hoop a hole would have to be drilled through the body, if the hood extends far enough outward and you line everything up you might be able to connect the main hoop bar to the SFC. however i dont think thats possible the main hoop bars bend inwards slightly and mount too far inward toward the center console. basically means you would need to develope a SFC that is farther inward.

did you stitch weld the SFC along the rocker panel? from what I heard the perimeter type SFC need stitch welding to the rocker to really get all the stiffness of the design of the SFC. Ive stitch welded mine (but i designed mine and im not running aftermarket SFC).

 

I dont know if it was mentioned, but there is an article in the new gm high performance where an independent corvette suspension was put into a third gen.

 

I think that was a C4 rear, wasnt it?

 

I can't remember, but is this a street car only?

 

It was a C4 rear, dana44. That article was based on a thread here that a guy started, but i believe he got flamed too much and then he stopped the thread. I was watching the thread to see how it turned out. The car was the same color and I definitly remember the pics... GM peformance just used his pics! they didnt even take ones for themselves lol.

But that C4 swap is not the same thing as the tq tube... the trans is still attached to the engine in the C4 swap. The tq tube basically extends the end of the crankshaft all the way to the rear of the car, then the trans and rear are bolted where the rear is originally placed, this basically moves the trans (and the weight of the trans) all the way to the rear of the car. Supposidly it also cuts down on drivetrain losses as well. I dont know about you but the 700r4 with converter weighs a good bit, its hard to transfer 150-200lbs to the rear of the car to help with weight distribution.

 

I know your not the source for this but, as a general question (to anyone)... How would moving the transmission to the rear of the car even remotely affect drivetrain loss ? Rotating weight is... what it is.

 

I think the drivetrain losses he is referring to is the substitution of the rear end with the transaxle setup. I once read that one of the reasons GM moved it back there was to reduce friction...
Typical rear drive power transmission= Clutch > transmission > rear end.

C5 transaxle setup = Clutch > Transaxle.

It's a little more complicated than that, but making the transmission and rearend one unit cuts down on friction.

 

Ok i'll try to explain. The tq tube doesn't have u joints... it has rubber couplers... this means less friction and less weight which means more power and less drivetrain loss. Now bc the tube is attached to the back of the engine and the IRS rear (both are fixed to the car) that means there's much less unsprung weight. Not to mention the tube acts as a chassis brace and adds to the overall rigidy of the cars structure. Believe it or not driveshafts flex and bend and wobble... tq tubes do not. This means less friction swell. So less weight, less friction, added rigidy and less unsprung and rotational weight means less. Drivetrain loss.

Oldchevys had tq tubes as well... but tq tubes increase vibrational noise so they ditched it. But they've fixed the issue so now its win win.

 

Subscribed!

 

Okay everyone, here is a long overdue update. I've been a little busy with the birth of my second daughter and then my wife getting very sick and ending up in the hospital for a week.. At any rate I wanted to do a quick mock up of the torque tube and motor just to see where things would land. So after my spohn motor mounts showed up I got to work and got the motor in the car, well just a mock up block for now, and yesterday I picked up the six speed torque tube fromy my buddies house, I am glad I did because there is roughly a three inch difference in length between the A4 and M6 torque tubes. Here are some pictures below, I was pleasantly surprised to find that the shifter mounting tabs on the tube are within a couple of inches of lining up with the hole in my floor and the front section of the tube (bellhousing) area fits nicely. The rear bellhousing area shows pretty clearly where the floor will need to be modified, which is roughly the area on the tunnel hump in between the rear lower seat cushions, the good news is that I dont think it will need to be modified a whole lot and after that area under the car it pretty quickly opens up into the gas tank/rear end area which has a good amount of space. Sorry for the crummy picture quality, my car is about 2 feet off the ground and getting great pictures showing everything is kind of tough......






I am hoping that I can get the car over to the shop soon to get started on the tough stuff. Thanks for all of the great discussion going on here on the thread, lots of great questions and ideas, I will do my best to document this for everyone's reference. Thanks!

 

Quick Update, car is going to the shop early next week! Lots of pictures to come!

 

Sorta offtopic, but I came across this info. If you go to http://www.gmheritagecenter.com/gm-h...tion-kits.html and Camaro -> 1990 -> pg.110
It has front curb weight listed as 1911 and 1437 for the rear, which makes total weight
3348. So according to this source it´s 57/43 stock.

82Camaroguy, do you have new pictures from the shop yet?

 

I am working on arranging the trip over to the shop either tomorrow or Thursday, so I should have some updated pictures and stuff pretty soon.