VW Corrado V8 RWD

[ViolentBlue]

I figgured I'd post this here

I just started collecting parts for this build, so no pics yet.

Heres the plans
'93 VR6 corrado
4.2 Audi V8 (actually came out of a VW Touareg)
Megasquirt and hybrid EDIS/COP ignition
porsche 924 Turbo (G31) bellhousing, torque tube, and 5 speed
VW Syncro rear end (differential removed, and 5 speed located in its place)

having quite the time finding the 1 year only trans and torque tube, but I believe I have the correct bellhousing lined up, so I can figure the clutch out and begin wiring the engine management .

the engine will phisically fit in the front, hood will close. with the 924 torque tube setup it will clear the stock R&P and I can leave the front suspension pretty much alone (suspension has already been upgraded on the car so I'm glad about that)

the all aluminum V8 will weigh a little less than the Iron VR6 in the car currently, so shouldn't mess weight distribution too much.

the Syncro conversion has been done on corrado's before, and its "almost" a bolt on affair, mso I shouldn't have top cut apart the tunnel, but I'll probably (read I'm living in a dream world hoping that I won't have to) cut out the trunk floor sheet metal, and replace it with the trunk floor from a syncro passat, which will raise it by six inches for more room under.

I keep hoping that I'll get something solid as far as parts go. I already have the engine, I have a deal arranged for the syncro rear end,- just waiting on delivery, but everything else is up in the air at the moment.

[MarKoBrow]

does it have to be a 924 Bellhousing? I know of a 944 in a junkyard that is unmolested

[ViolentBlue]

as I understand it, the early 944 bellhousing is virtually identical to the 924 Turbo unit. the torque tube and shift linkage are specific to the trans being used.

(hey I almost sound like I know what I'm talking about)

[MarKoBrow]

I will go and get the year and maybe snap a few pics of the car and post them if it will help. I just saw it there yesterday

[ViolentBlue]

a quick shot of the engine siting in the garage, and the peanut gallery looking on.

[jadewombat]

Any updates? Reminds me of the Vorsche Golf.

[ViolentBlue]

got someone building the MS3 loom for the engine now.
Need to track down:
G31 trans, torque tube and bell housing.
also looking for Passat Syncro rear end assembly.
once I get those I'll be good to go.

[ViolentBlue]

got a nice low mileage G31 with LSD, as well as matching bellhousing.
also got a factory engine bay wiring harness for the engine. we'll adapt the MS3 to it, for a factory look.

need to find the proper torque tube yet.

[Dave at Pelican Parts]

I have read that the 924 and 944 transaxles are not awfully strong, and don't hold up well to lots of torque. Hopefully I'm wrong about that, or you have a steady source of them.

--DD

[ViolentBlue]

Originally Posted by Dave at Pelican Parts

I have read that the 924 and 944 transaxles are not awfully strong, and don't hold up well to lots of torque. Hopefully I'm wrong about that, or you have a steady source of them.

--DD

as I understand that is true of the Audi sourced boxes. However the early 924 turbos used a porsche box, that used 915 components, making for a incredibly strong box.
but this was only used for a couple years, thus, rare as hens teeth.
mine just arrived part number 931 031 031 OR
if I am correct this is the G31 capable of handling 300+ hp

[962porsche]

the G31 boxes are pretty much all the same they are all audi boxes and not at all Porsche boxes .
the G31 -03 box was used on the 924 Carrera GT's race cars only and by your numbers you listed it is not one of them it would be a g31-02 box with out the extra hardened gears . the G31-03 boxes have harder gears other then that they are all just as strong .
yes they will hold up to torques every well to about 400 with out doing burn outs all the time .
if you like roasting your tires all the time then they will not hold up to more then 250 torques .
HP is not what will damage your gear box torque will .
it's not the gears that will brake it's more the cases that brake one of my V8 944's is a 350 SBC with 428 torques and 407 hp the car is used for endurance racing only and other then braking one gear box case pulling out of our pit stall with to much of a launch . THEY WILL hold up .
the half shafts are I should say the CV's will tend to give out 1st . I installed beefier half shafts and CV's . so instead of the cv's braking the case of the gear box broke . we now just run the stock 944 half shafts and it's been years with no brakeage at all . once the car is rolling you can get on it but not from a standing start with full slicks . you could run a 951 gear box and we do at some events as the gearing is different . we swap out the boxes for the tracks we run at to dial in the gearing to the track . it's easier to just swap out the boxes then to tear down the hole gear box to change the gearing in them . we do run trans coolers on all of the boxes and to aid in quick gear box swap outs we removed the spare tire well .

[ViolentBlue]

pulled the ring gear from my aluminium flywheel, and remachined the shoulder to fit inside the Touareg flex plate. same concept as the 034 adapter.
i'll pull it all apart and replace the main seal once I've got everything figured out.


VW Touareg bellhousing in place, as well as the Pressure plate


perfect fit, Hydraulic clutch assembly from a Borg Warner T5. I have the backing plate being laser cut right now, should bolt up and require maybe 1 or 2 shims to set perfect.

[ViolentBlue]

ha ha, Success finally.
Porsche 944 use a 1" x 23 spline for their torque tube but uses a much smaller disc. it appears the disc that came with my kit is 24 spline and slightly less than 1"
I've been told that the 23-1 is a common setup should be easy to find the right disc for it, but its been a bit of a battle.
but the perfect combo of 235mm diameter and 23 splines is not easy to come by. mid 70's Chrysler used that setup, bu you cant get those parts, and just found out RX8 also uses that setup, which means, there re performance parts easily accessible, and eBay has provided some inexpensive but performance ready options.
now I just have to wait for my delivery to continue.

[ViolentBlue]

Laser cut pieces were done today.
so i took the time to tap the holes that needed it and assemble.
I'll give it a lick of paint before installing on the engine, once my clutch disc arrives.


I bought a cheap 90mm throttle body on Ebay, took some time to draw up a 2 part adapter to bolt it in place of the Fly by Wire unit.
hopefully it will be ready tomorrow.

[ViolentBlue]

looks like a lot of the earlier pictures are now defunct, I'll repost from my facebook photo album

aluminum flywheel machined to slip inside the OEM flex plate, there was no manual option for this engine originally.


Bellhousing from the original 6 speed auto, taking measurements toadapt it to the Porsch 931 transmission and torque tube.



adapter in place, laser cut from 3/8 mild steel, it has more than doubled the weight of the original aluminum bellhousing, but plenty of meat for everything to bolt to.


not my car, but virtually identical, mine is a '93 VR6 with auto. the new aluminum V8 will weigh about the same as the old iron block VR6, so balance should be good.


And the engine, AXQ V8 from an '06 Touareg. keep it all in the VW family. 300hp stock.


931 trans with LSD, good for 300+hp, and all in a tiny package, that should fit in the same space as the Syncro Differential and Viscous coupler location.


Rear end from a Canadian Syncro Passat. Corrado used same floor pans and tunnel as the passat, so it is almost a bolt in. need special suspension mounts, and new trunk sheet metal, but it can be done with a minimum of fuss.


syncro rear suspension mostly installed on a similar car for referance. I think on the Corrado with the 931 trans, I can get away with cutting out the spare tire well, and welding in a flat sheet in its place., May even have room to use the stock fuel tank.

[ViolentBlue]

got the belhousing finished, clutch assembled, hydraulic clutch slave installed
Throttle body adapter finished and installed.

[ViolentBlue]

oil ports for the cooler and filter assembly are just the right size to be tapped out to 1/2" NPT
tefflon tape and a couple Brass fittings and I'm ready to go for external filter/cooler.
don't rag on me for using coolant hose for the oil, its just a 2ft loop untill I can get it installed in the car, not a permanent fixture.