Sharkey's 944 corvette t56 swap thread

[sharkey]

So i figured id start a thread on my upcoming project on my 944, and thats to swap to a corvette t56 transaxle and torque tube. my goal here is to give a detailed account of what it takes to put the corvette driveline into the 944. i have yet to find a detailed thread on this swap start to finish, there are multiple cars running around with the swap, and other still in progress, but info seems a little scarce. obviously there are multiple ways to go about this swap, this will be my take on it, but ill try and detail other options along the way.

first off, my engine swap is a little different. for those not familiar, im running a chevy 2.2l ecotec, and right now im around 500 whp. i have a swap thread HERE and a photo gallery here . some may question why i need a corvette transaxle with this engine, surely the AOR transaxle with AOS final drive can stand the power from a turbo 4 cylinder, and its done well so far. i drive it pretty easy, no launching, no burnouts, etc. well my plans with the car have changed, originally i built the car for street and with the intentions of getting into track days, but after 5 years i have yet to get on a road coarse. my local track doesnt do open lapping days, they do private track rentals to groups, and unless you have an in (which i dont) with a group your out of luck. my next 2 closest tracks are members only facilities, and again, if you dont know a member (or have $50k for a membership) your out of luck. so with that, ive decided to switch my focus to drag racing. a bucket list thing for me is to compete in a drag week style event, and i figure instead of building another car for that ill make some changes to the 944 and do it in that. my goal is a solid mid 10 second stick car.

so that being said, my swap will have a few differences than with a v8. all these differences will be from the front of the torque tube forward. my engine currently is mated to the porsche torque tube, the torque tube flange is in the same spot as any other 944, so the torque tube and transaxle will end up in the same location on mine as an ls swapped car. i will detail my clutch and bellhousing setup, but if you use this as reference for a v8 car everything you use here would be factory corvette, clutch, flywheel and bellhousing, and will all bolt together as it was designed to.

[sharkey]

so the first thing is selecting a transaxle and torque tube. i ended up being given a 2005 transaxle, which isnt the best option, but more on that later. here is some info on some options

c5- the transmissions themselves are mostly the same from 97-04, however there are some variances with the diffs. all manuals came with 3.42 ratio, automatics came with 2.73 or 3.15 and are interchangeable with manuals. the cases have been upgraded through the years, in the c5 era there were single rib and 3 rib cases. the 3 rib is often called a z06 diff, the c5 z06 first got this case, but around 2001+ all corvette manuals got the 3 rib case. all c5 transaxles mount under the rear of the diff

c6, 05- this one is a bit of an oddball, the transmission is the same as a c5, and the diff had the the new mounting ears off the side covers. these diff cases are known for being weak, the new style mounting ears changed where the load is put on the case. this shouldnt be a big issue in a 944 swap as most wont use the mounting ears, however it would be best to avoid this diff. this is the diff im using, however ive designed a brace kit to hopefully fix the weak points. z51 models got a transmission oil pump and a cooler.

c6 06-07- this is the same t56 as prior years, however the tailhousing was changed to a stronger design to coincide with a new diff case. the diff case got completely redesigned to address the weak points. the diff and tail housing from these transaxles can be swapped to an older transmission, but the tail housings are getting hard to come by. the z06 models got an upgraded 30 spline mainshaft in the transmission, a 30 spline pinion gear in the diff, along with a stronger passenger side output shaft and diff side gear. its common to swap the shaft and side gear into previous diffs. the z51 and z06 got a trans cooler system, and the z06 got a diff cooler.

c6 08-13- 08 is a new transmission, the tr6060. sharing the look of the t56 is about all thats the same, these are much stronger transmissions. all models got a 30 spline mainshaft, all the gears are physically larger, more refined syncros, etc. the diffs stayed pretty much the same.

c7- this is a tr6070 7 speed manual. these got an electronic diff. i dont have much info on this setup, i had no need to research them.


torque tubes

there are multiple lengths of torque tubes for manuals (autos wont be discussed)
c5- 54.375"
c6 05-07- 55.875"
c6 08-13- 55.75" (not 100% on this length)
c7- 53.5"

the c5 has 2 different manual trans torque tubes. 97-2000 had 10mm bolts in the driveshaft couplers, 2001+ (often called the z06 torque tube) got changed to 12mm bolts.

the c6 torque tubes changed with the change to the tr6060, the tr6060 was longer so gm shortened the torque tube. some people claim the c6 z06 torque tube is lighter, i cant find much info on that though.

i can confirm the torque tubes between 97 and 07 are completely interchangeable. from what i can find, the torque tube 08-13 is the same aside from length, so it should bolt right up to any earlier transmission. the c7 torque tube was something i was interested in because of the length, however i wasnt able to confirm it would work with the earlier transmissions. i suspect it would, the bellhousing on the rear of it looks the same, and everything uses the typical gm 26 spline input shafts.

now here is some info on driveline important lengths

transmission length, 97-07- 19.315"
diff length from mounting face to axle centerline- 4.600"
total length of transaxle, mounting face to axle centerline- 23.915"

944 torque tube flange to axle centerline- 77 3/16"
c5 tt to axle centerline- 78.29"
c6 early tt to axle centerline- 79.89"
c7 tt with c5/early c6 t56 to axle centerline- 77.415"

going strictly off the measurements, the c7 tt and t56 transaxle seems like the winning combo, and if i could have confirmed it would work i would have gone that route. being the price difference between a c5 and c7 tt ($200 vs $800) i decided against experimenting. the less than 1" longer c5 driveline will work just fine. for most doing a corvette driveline, the c5 stuff is a good choice, especially if you can get it all from one car. another option would be c5tt and 06-07 transaxle for the stronger diff/tail housing. even stronger would be the c5 tt and tr6060, although this is an untested combo in a 944. imo, either c6 torque tube is unusable, both are going to push the axles back too far.

gear ratios

base and z06    z51      zr1
1st-  2.66        2.97     2.29      
2nd- 1.78        2.07     1.61
3rd-  1.30        1.43     1.21
4th-  1.00        1.00     1.00
5th-  0.74        0.71     0.81
6th-  0.50        0.57     0.67

common transaxle upgrades in corvettes

torque tube couplers- inside the torque tube are 2 rubber couplers. while they are strong and offer some dampening in the drivetrain, people often upgrade them. solid aluminum versions are offered as a race part, and aluminum with urethane insert versions are offered for cars seeing street use.

driveshafts- with high power and rpm some have found the driveshaft to flex inside the tube. larger aluminum driveshafts exist, along with carbon fiber.

transmission upgrades

syncro rings- all corvettes got fiber rings, however the aftermarket has carbon/kevlar rings that hold up better with high rpm.
syncro keys- the stock keys are stamped steel, and a failure can be catastrophic. aftermarket billet keys are a wise upgrade for at least 1-2 and 3-4.
shift fork pads- another cheap upgrade is to change the plastic fork pads to aftermarket bronze ones.
3-4 fork- other versions of the t56 have an aluminum 3-4 shift fork thats prone to failure when banging gears, the upgrade is a steel fork. luckily, all corvettes have this fork.
gearsets- there are multiple aftermarket gear set options from just changing 5th and 6th to ratios better suited to high strung engines, to full straight cut face plated gears, its all out there for the t56.

diff

all corvettes have a clutch style limited slip. eaton has a replacement clutch style diff, and wavetrack makes a torsen style diff
output shafts- high high power and sticky tires corvettes are known to break outputs. the c6 zo6 passenger side output and side gear is a common upgrade. there are multiple companies making output shafts and side gears out of exotic materials
gear ratios- corvettes have everything from 2.56 to 4.11s available. factory 2 series diffs require a special "thick" gearset to use a ratios 3.15 and up, however this wont apply to most as 2 series ratios are auto only. it seems most people argue over whats better in a corvette, 3.90 or 4.11.

transaxle braces- several companies offer braces to go from the front of the transmission to the diff to prevent the transmission tail housing from cracking. this is a wise upgrade for anyone, although if you dont plan on high power or racing may not be needed.


here is my choice of setup, a 2004 c5 torque tube and a 2005 c6 z51 transaxle



i split the transmission apart for inspection and some upgrades




billet keys vs stamped keys


bronze fork pads


also pulled the diff apart for a 4.11 yukon gearset



this is one of the outputs often upgraded. i left it stock for now.


and the new gear set


torque tube


all together

[sharkey]

with the corvette transaxle wanting to occupy the same space as the torsion tube, a major change here is needed. no matter what you do you will need to cut a section of the floor under the back seat, and you will be doing a rear seat delete.

option 1- swap to corvette
going this route you remove all the porsche rear suspension and put in the corvette cradle, knuckles, control arms, etc. this route requires a fair bit of structural changes to the back of the car to mount the cradle and upper control arms.
pros-easy to mount the transaxle
-uses stock corvette cv axles
-better rear suspension design
- better brakes
cons- complex structural work
-very wide track width, needs flairs or widebody
-different bolt pattern than front

option 2- modified torsion tube
this route removes the torsion bars and requires full coilovers. the torsion tube is cut in half and a U is welded in the middle to allow the transaxle to pass through. uses the stock trailing arms, brakes, etc. the transaxle is generally hung from the top.
pros -less fab work
-mostly uses factory parts
cons -requires custom axles

ive decided to retain my factory rear suspension, to me its the most logical choice. so skipping over all the fab work (im not there yet, ill show what i do in detail later) the next big thing to sort out is axles. going from the corvette transaxle to the 100mm type 2 flange can be done in several ways, depending on how strong you need it.

1)all out
-930 style flanges for the transaxle. these are common for corvette axle upgrades. made by geforce, drive shaft shop and other. i priced the geforce ones, they were $800usd for the pair
-930 style cv joints. pick your brand
-outer adapter flange. your going to need to convert the outer stub axle from 100mm to 108mm bolt circle (type 2 to 930). im using an adapter from PRD racing products, although drive shaft shop and lindsey racing use the same sort of thing for their 944 level 5 axles

2)
-930 flanges for transaxle
-108 to 100mm adapters to bolt to the 930 flanges
-use type 2 (factory size) joints and a shorter axle

3)fusing corvette and porsche axles
-corvette inner cv joint. the factory corvette c5/c6 axle shaft/joint use the same 28 spline as a 930 cv joint. some corvettes use a tri-lobe inner plunging joint while others use a plunging 6 ball setup. wither will work, although id assume the 6 ball is stronger. *this may not work non oem corvette axles, my parts store replacements were a different spline size*
-100mm to 108mm adapter for outer
-930 cv joint for outer
-28 spline 930 axle shaft

im going with the 3rd option. i feel the 6 ball corvette inner joint will be plenty strong. the only thing i dont like about this (any of it) is the adapter on the outer stub shaft. it would be so much simpler if there was a 108mm (930) flanged stub shaft that fit a late 944, but to my knowledge this doesnt exist (if it does please post it). ive decided to use empi parts to do all this. im using a 930 race joint for the outer, and will be using empi axle shafts once i determine what length i need to order.

here are the adapters


outer cv joints, empi 930 race joints with chromoly cages, small 930 boots, hardened steel boot flanges and spirolox snap rings


corvette inner joints taken apart






this is about all i have to show right now. my car is currently sitting in my showroom at my shop for safe keeping while i wait for some more parts. currently im waiting on my clutch and flywheel to be made and shipped, and waiting on coilovers to ship. once those parts are in my hands ill be stripping the interior, removing the old drivetrain and start cutting the car up.

[Myporschels]

Thanks Sharkey for this! I too have been searching for some detailed info on this swap. In my case, i have a fresh LQ4 6.0 ready, but have been struggling with the set up. This summer i found C5 transaxle, TT, and complete rear end including frame rails neatly removed from the Vette. So my plan is to fabricate those into the 944 and bolt up rear end, then work forward. Intend to find Corvette or Camaro front end as well. What are you seeing with the 944 tunnel? Will we need to split and widen it?

Keep the updates coming.

Mike

[Geoff Daniels]

Thanks for the great info and taking the time to document your work. I have a 1986 951 that I put a hopped up LS6 in several years ago. I kept the original Porsche turbo (not an AOR) tranny at the time but have been considering an upgrade to the T56. I was able to acquire a T56 transaxle and TT from a friend that had a mishap with his 2001 Z06.

I will definitely be following your progress.

Geoff

[sharkey]

 What are you seeing with the 944 tunnel?  Will we need to split and widen it?

i dont believe the tunel itself is that much of an issue. yes, things will be tight, and the area around the shifter may need to be cut out, but i dont believe it needs a complete redo. im planning to look at the feasibility of moving the shifter from the side of the torque tube to the top, or at least a little farther up the side of the tube, this would help with tunel clearance, and my goal is to get the shifter in the factory spot in the console.

under the back seat area, thats a different story. i have 2 thoughts on this and im not really sure what way to go. can either cut the smallest amount of floor out to clear the trans, or take the whole section out under the seat and make a nice flat floor that goes from the front of the rear seats area up to the trunk floor. this would make finishing and carpet much easier, and would look better imo. ive gotta see what im dealing with once its all apart to decide what i wanna do. unlike what some people have done, i do plan to keep the entire trunk floor, imo there is no reason to cut it out.

[Myporschels]

Mine is automatic, so will still have to address shifter console area. By the way, i have a manual C5 shift lever if you need it... i plan to cut out entire back and rebuild with roll bar assembly and then area for fuel cell. Glad to hear that the TT should fit in tunnel

[Raymond-P]

Sharkey...I’m really excited you are going this route and posting this thread!  

I just retired and I’m at the torque tube rebuild and transaxle swap stage for my Porsche project.  It's been a long time coming and I finally have the time to finish it.

A T56 conversion has been enticing from the very beginning and I’m anxious to see how it goes for you.   I know your are certainly qualified and your prior LS conversion work has been well documented and very helpful to those of us who followed in this forum.

I'll be following along!


“Let no one seek his own, but each one the other’s well being.”
I Corinthians 10:24

[sharkey]

i havent yet had a chance to start any work, but i did get one more critical piece of the puzzle, and thats the clutch. for anyone looking at this thread as a reference for an ls swap, just ignore the clutch stuff, it wont apply to you (just use an off the shelf clutch for a corvette of your choosing)

the clutch i went with for the ecotec was a little complex to sort out. when i first started planning the t56 swap i had planned to just get a new disc for my current clutch setup (spec 3+, using a 6 bolt ecotec flywheel, cavalier ecotec pressure plate and a 944 n/a disc). a disc for a 2.4l pontiac solstice would have fit fine, its the same diameter and the same spline as the t56, however the problems came in this year when i switch to e85 and turned the boost up, i was able to drive through the clutch quite easily, it appeared i was at the limits of what i could put through a 215mm single disc clutch. after a couple months of dealing with clutch companies trying to sort out a 7.25" twin disc and getting nowhere i discovered spec clutches had an off the shelf solution.







this is something spec clutches makes as an upgrade for a 2.4l (non turbo) pontiac solstice. it starts with a billet conversion flywheel that allows the solstice 2.0l turbo sized clutch (240mm) to be used on the non turbo engine. the rest of the clutch is a stage 3+, however the pressure plate has been further upgraded with a stiffer diaphragm and a billet steel apply plate. spec claims this setup will be good for 671 lb/ft, so im hoping itll be all i will ever need.

another thing ive got done is my bellhousing adapter plate. i run a quicktime steel bellhousing that converts the ecotec to the t56 (non corvette) pattern. i drew up an adapter plate to go from the standard t56 pattern to the corvette torque tube pattern and had it laser cut from 1/4" steel.



this plate can work for any setup using a t56 bellhousing that bolts to any engine. i also have one designed that goes from t56 to 944 torque tube.

[kevin924kevin]

The vette trans and torque tube fit nice. My 924, i widened the tunnel a bit to 6" for better clearance.
I have the LS3 and Z06 6 speed. I am just waiting for my body guy to take the car and complete my custom body mods. I am using the factory S2 suspension in my car. X-chop made my 930 axle adapters at the wheel side and my 930 stubs into the vette trans are from 928 Motor sports.

[sharkey]

alright guys, ive got some updates. last weekend i started tearing into this and have gotten a decent amount done. i was hoping to make this swap with as minimal major changes as possible, however within the first few hours of working on it i had already decided i was ditching the stock fuel tank and cutting out the spare tire well. i discovered the transaxle brace kit i had built was going to foul on the fuel tank (things would be very close without the brace), and i also determined i could get the transmission pushed up higher without the stock tank.

so not to bore you with disassembly pics, ill jump right into fab. so the tunnel around the torque tube is tight, the ribs in the tunnel are just barely touching the torque tube. i have yet to address this, however ill likely just cut them out and weld strips in flat to smooth the tunnel out. starting with the main structure under the back seat, the crossmember was cut between the support brace mounting points, the floor was cut forward roughly a foot, and that section of tunnel was removed. the main crossmember was later cut wider, removing the inner brace support bolt locations.





next the transmission was hung in place







next the transmission crossmember was built. instead of modding the stock crossmember i built a crossmember out of 1 1/2" dom tubing. the transaxle brace i designed integrates a mount to hang the transaxle from, and im using some 1 1/4" urethane bushings for mounts. the crossmember bolts into the factory crossmember bolt holes along with the fuel tank strap bolt holes, and ill add 2 more bolts on each side on the vertical





the torsion tube always is a big deal with this swap, most people do a horseshoe above the transaxle, but i decided to do things a little different. remember that brace that bolts into the main crossmember in the floor where i cut? that location in the floor is very strong, and the mounting locations are indexed. i machined up a steel tube with the register to index into the floor, and these were welded to the torsion bar tube with some 1/4" steel plate. this will index what is now just the trailing arm mount on the inside. combined that with 3 mounting points on the outside of the tube (2 on the aluminum bracket, plus the torsion support arm) its not going anywhere. this also has solid aluminum lower torsion mounts, solid upper torsion tube mounts, and urethane spring plate bushings





the i had to relocate the swaybar down roughly 3/4". i run a splined universal swaybar, i had a set of plates made to bolt the swaybar up to the torsion tube in the factory location, it was as simple as making a new set to lower the swaybar down. the swaybar still sits no lower than the bottom of the floor.



the spare tire well has been removed to make room for the new fuel cell.



so another reason i decided to remove the stock fuel tank was so i could push the transaxle up a little higher. i was able to get the cv axle angle just about flat with the suspension at ride height. this is a huge thing for me, as the axle angle gets to far out of wack, like with the original transaxle and lowered car, thats when you have axle problems. i was able to measure for axle shafts, they need to be 17", i have ordered empi 16-2225 axle shafts, they measure 17 1/2", so i likely will have to shorten them a little.

during this whole process ive also decided on doing some other things. i decided im going to put an nhra legal 8 point roll bar in. doing this will add structure to the floor and main crossmember, i hadnt really planned to do this till i needed to, however it makes sense to do it now.

[Hotrodz of Dallas]

I wish I had the equipment you have to work with. My shop just doesn't have the room for it.

[Raymond-P]

Sharkey,

Wow!  Great progress.

[sharkey]

not a whole lot of progress, but i did get the axles put together today.

as a mentioned before, i am using a corvette inner axle joint, a 930 outer joint and a type 2 to 930 adapter. the axle shafts are empi 28 spline 930 axles, they are 17 1/2" long. i machined the axle shafts for an inner snap ring to reduce movement of the joints (axles are designed for buggies with long travel suspension and need more plunging than the joints allow, hence why they dont run an inner snap ring).



the grooves were cut 1.120" between the inner edge of the grooves for the 930 joint and 1.200" for the corvette joint. after some assembly i have a pair of corvette to 930 axles





obviously i have to fully assemble the axles yet. the corvette inner boots need some work to fit. the diameter of the corvette axle shaft is larger than the 930 shaft, so the boot has a larger hole in it. i need to sort out a grommet/spacer of some sort, or else a different boot. overall im confident in this axle setup, however i cant help but think it would be better off with a non plunging 930 cv joint. the corvette joint has a lot of plunge length, making the plunge of the 930 joint unnecessary. i briefly looked into non plunging 930 joints, they seem to triple the price of a regular 930 joint, so i didnt bother.

[Okie]

Hello Sharkey, build looking great so far. I was wondering if you had any updates on it? I am looking to buy a 944 NA or turbo and build a 450-500 whp car with a 6.2 LS3 and I figured that either of those trans axles would need to be swapped as well. Also, if you could guide me into which model to go with on this swap, the NA or Turbo, because I’m not sure that the turbo can handle that much torque and HP but I’m new to Porsche, so fire away.

[sharkey]

not much for updates. ive collected some more parts, and my fuel tank is built. i just havent had any time to work on my own car, ive been slammed with work and cant seem to get enough time to get the car back into the shop.

a 944 turbo transaxle with a case stiffening plate and the .72 5th gear swap will work for what you have planned, providing your not trying to do burnouts or launch the car. there is also the audi 01E swap, i know of a drift car running one of those transmissions with a twin turbo ls and its holding up. ive heard a company is making parts for this swap (cant remember the name), and its much simpler than my swap.

[sharkey]

ive finally got the car in the shop again, and managed to move forward on the sheet metal work.

so we all know that the floor in the back seat area needs to be cut, but the tunnel is also an issue. the corvette torque tube is as wide as the tunnel is at the top, and while i was able to fit it in the tunnel enough to build everything so far, the tunnel touches the torque tube in a number of places. one option for fixing this is not fixing it at all, although engine vibrations will be transmitted into the body. this may be fine for a race car, but im not cool with it. another option i came up with was to cut out the offending areas (mostly its the ribs in the tunnel causing issues) and weld in flat strips. alternatively, a mini sledge hammer could also sort things out here, although its going to make a mess. yet another option ive seen done is to cut the tunnel open down the center and add a strip to it. this is a decent option, however the tunnel will end up narrower at the bottom than the top, its not a big issue but it could present some issues during assembly and repairs. in the end i chose to go about as invasive as you can get and cut the entire tunnel out and build a new one.

you can see here what i had cut out of the floor to this point



and here is what i ended up cutting out of the tunnel. i stopped at the point the tunnel flattens out in front of the shifter, i figured this would be a good transition point. also, ahead of there had no areas that were touching the torque tube, it was a little snug but alright.



making the tunnel started with a cardboard. template cardboard is easy to cut, tap pieces on, and even acts like metal when you bend it in a brake.



the cardboard template is then removed and unfolded and traced onto metal



from there it was cut out, bent up, and some step rolling adds the inserts. i didnt get pics of it till it was tack welded into place



from there i moved to the back of the tunnel above the transaxle. i had a tough time coming up with a way to do this that i liked. to me it still looks a little odd, but it will work just fine for what i have planned for finishing the back seat area. again, this part was templated in cardboard, rolled, bent and step rolled. the transition between the rounded rear section and the square tunnel was interesting to make, this required some hand forming and hammer work.





so thats the sheet metal all built and tacked in place. since then ive removed the transmission and torque tube, and spent hours scraping and grinding undercoating off around the seams. all the seams will be fully welded. a couple areas still need some attention, but for the most part after welding that will wrap this part of the project up. and yes, the console will still fit. having the complete console was the motivation behind the next thing...

the shifter location is another thing you need to decide with this swap. the shifter with the corvette setup is offset to the drivers side, and ends up a couple inches further back (closer to driver) than stock. the most common thing here is to cut the tunnel out and make a box around the shifter. i had originally intended to widen the tunnel enough to fit the shifter in the corvette location, however it was looking like the tunnel needed to be around 3 to 3 1/2" wider than stock, which is not ideal. the other thing with the shifter in the corvette location is the center console, essentially the shifter ends up dead center of the upright on the late model center console. i contemplated cutting the console and widening it at the back, removing tits natural taper, or even cutting it off at the switches and finishing the end off, but really wasnt happy with that. i decided to move the shifter location on the torque tube.

here is the stock shifter mounts



i cut the lugs off and machined up some new mounts and welded them to the torque tube. ignore the tack "welds", i cant weld aluminum, they held for the time being and have been properly welded since.





you can get an idea how far i moved the shifter forward based off that strap thats still on the tube. originally there was a piece on the shifter that sat in that strap, ive cut that off. the new mounting bosses are on the exact center/top of the torque tube, this still makes the shifter offset towards the drivers side, however what sticks up through the floor and console fits in the stock holes, and a shifter boot will easily cover it all up. the shifter mounts will need a little work, i feel only mounting it off the 2 bosses without the brace on the other side will eventually lead to the shifter box breaking the mounting tabs off. i havent put much thought into this yet, ill have more on that later. the shifter rod shown was a mock up to build the tunnel around. the shift rod no longer has any dogleg to it, its a straight shot between the shifter and the trans. while i have the transmission out of the car i will put everything together on the bench and build a new shifter rod, along with the additional shifter mount.

[sharkey]

there are a few more things i have slowly gotten done. my fuel cell is nearly done. i decided it was best to ditch the factory fuel tank. some people can make it work, i think an early tank would be the best candidate, but i felt a my best coarse of action was to eliminate it and have a cell built.



the sending unit is a bit of a problem, its an odd resistance range and i wasnt able to find a suitable aftermarket replacement, so i had to make the stock one work. i ended up spinning up a retaining ring on the lathe, then drilled and tapped the tank and threaded bolts with sealing washers from inside the tank to give me a stud. the retainer ring just goes on with 6 nuts. the rubber seal on the sending unit is what seals it to the tank.



the fuel pump was a big part of why i went with a custom tank. im not a huge fan of external efi pumps, especially high volume pumps. i much prefer the pumps being in the tank where the fuel helps keep them cool. for this i went with an aeromotive phantom stealth setup. this incorporates a billet fuel hat/pump hanger with pass throughs for wiring, feeds and return, as well as the vent line. it also uses a special fuel foam columb that keeps fuel around the pump inlets. if you noticed things in plural thats not a typo, this setup is equipped with dual aeromotive 340 lph pumps.







that much fuel pump may seem like overkill, however running e85 im in a little bit of a weird spot for pumps. a single 340 lph will just barely keep up with current power levels, and a single 450 wont do what i have planned. i decided dual pumps would be the best option, allowing me to run one all the time and stage the second pump through the ecm. this will help keep the fuel cooler while cruising than with a single large pump.

i still have to make tank mounts, and add in a tube for the filler.

something else ive gotten is my coilovers for the rear. no matter what, a coilover conversion is needed for this swap, there are lots of options out there but i decided to go something less typical. i worked with QA1 to put together a double adjustable coilover shock. these will allow for more adjustability to get the car to launch the way i want it. i went with a 10" long 450lb spring, this is a bit of a guess and will likely change (its looking like the free length of the spring may be too long). im using racers edge lower coilover mounts.





something else not directly related to the swap, ime replacing the worn out stock seats with a pair of kirkeys



i actually took these out of a customers truck. they had some uprights welded to the bottoms, i had a set of aluminum mounts laser cut and bent to bolt into the factory bolts.



i also got a piece cut out and tacked in place to fill the hole were the spare tire well was



i think that covers most of what ive gotten done since i last updated. i wish i had more updates cause it would mean ive gotten more done lol. im hoping to get all the floor welded up this weekend, and maybe start mounting the fuel tank. the roll bar will be the next, and hopefully the last major fab work, and im hoping to get that pretty quick.

[sharkey]

its been a long time since ive updated this thread, i have been a little busy to. the car has been on the road for a couple months now, im still ironing out small thing, but so far its working well. ill pick up where i left off

with the sheet metal all tacked in place, the trans and torque tube all came out for welding. hours of welding and grinding later and the car is solid again. everything was seam sealed, primed and undercoated.






i mentioned earlier that i moved the shifter more towards the center of the torque tube to line up better with the console. this got all welded up, and a new shifter rod was made







from here on its final assembly. suspension and coilovers went in first (mainly cause i had to keep the car rolling)



clutch, bellhousing, torque tube and transaxle was next. i didnt get much for pics of the install, but got a few of my finished diff girdle/brace kit







i started getting a little impatient at this point, i needed the car out of my shop and i had very little time to work on it, so i came up with some quicker solutions to thing. my old exhaust fit close enough, i had to flatten the pipe under the trans a little. i had planned a new exhaust system, but it will have to wait.



same deal with the roll cage i planned to put in to tie the car together, i just didnt have the time to build it. i had to do something to tie the car together to support the inside torque tube mounts. a simple tube and some plates took care of this.



at this point the fab was done, so i took the car back home. i picked away getting things done. started with priming and painting the bare sheet metal inside the car



from here i started th wiring. i had a significant amount of wiring to do for my setup, seeing im running dual fuel pumps, a trans cooler fan, and everything on the transmission. most of this is controlled by my ms3x computer. i decided to use bulkhead deutsch connectors for everything, it worked out well and i have sub harnesses for everything making maintenance very easy.



the fuel tank was the last major task. i had a mount bent up for it, the top portion bolts into the trunk floor, and tank goes into the lower part and the lower part bolts to the top piece in the car. the tank mount also has the fuel filter and flex fuel sensor mounted to it, and the whole thing has one wiring harness that plugs into the body. within a few minutes the tank can be pulled, if needed.







at this point i ran fuel lines, blead brakes, tossed in some fluids and was able to get the car running again. i then turned my attention to getting the interior back together





i ran into a major glitch at this point. i had planned on a new carpet kit as with the amount of modification to the floor and tunnel, the factory carpet wasnt going to be a good fit. being my shop is an auto custom carpet dealer we gave them a call, turns out like many things right now, there is a shortage of material to make carpet. they were able to make the carpet kit, however they wouldnt sell us any extra flat carpet because of the shortage. being acc makes their own raw material i couldnt find anything that was a close enough match, and if im spending the money on carpet i want it to be good. my hands were tied, i ended up trimming the stained, worn out carpet, its the best i can do right now. ill have to revisit this when i put the cage in.

for the last couple months ive been driving the car on and off, slowly working out some glitches. i had some issues with the transmission being real noisey. long story short it was solved by changing fluid types (going from the gm recommended dexron 3 to the viper spec syncromesh) and mainly ignoring it. the trans is essentially in a sheet metal box pretty much beside me, with no carpet or sound deadening, and my ear is 18" from that box. mechanically, everything is good so far, some other noises from metal on metal suspension joints and such, but nothing im worried about.

electrically ive had some more glitches. the fuel gauge works, but it reads incorrectly. i didnt clue in earlier, but the shape of the factory tank means the fuel gauge isnt linear. ive got an autometer box to calibrate the fuel gauge, ill be putting that in at some point. the other big glitch has been the speedometer. of coarse the gm transaxle uses a vr style sensor not compatible with the factory gauge cluster. i had a method to use a signal converter with my ecm, however its been hit and miss. im trying another method with my ecm, i put it in last night, however i have yet to try it.

overall, it keeps getting better as i work out kinks. so the million dollar question, was it worth it? i think so. the gearing 1st to 4th with the 4.10 final drive is near perfect for my combination, however 5th and 6th are a little steep. 5th gear is a little too short to drive the thing as a 5 speed, i can use 6th gear requires around 120 km/h to even consider it. its also not the smoothest shifting transmission when trying to pussy foot it around town, however flat shifting at 8000 rpm is like butter. overall this combo just wants to be beat on.

oh yea, the other day leaving work i put it up on the 2 step, sidestepped the clutch at 5000 rpm with 6 lbs boost, it went up in a cloud of tire smoke, then grabbed 2nd and made more smoke, and i didnt even think twice about doing it. while not exactly the reason i did all this work, its nice to know i can screw around without worrying about hurting the drivetrain. im certain with a turbo transaxle that would have resulted in me getting the bucket of floor dry and shoveling parts into the scrap bin.

[racertomtom]

Heck Yeah! Excellent job and thanks for all the detailed information.

[Raymond-P]

Sharkey, you have one IMPRESSIVE body of work here!  I'm sure we'll soon be seeing videos of you thoroughly enjoying the fruits of your labor.

Kudos for always being out there on the edge, exploring, researching, documenting, and notably...sharing it with us all.