New convert under way

Good luck on your biuld. There are a lot of very smart individuals that have built 948s on this forum. This is my first build of this nature. A little update on the trans, sending the C6 back, missing to many parts. BUT, just finished buying off ebay a 2003 C5 complete transaxle, torque tube , shifter etc.This unit has 18000 documented miles, brand new basicly, so once this unit arrives i will get back at it, did managed to make a template from the first trans , this will allow me to move forward on the cross member section. Keep you posted, I will take pics of the front imput shaft ,it is out of the trans, for shipping.

Well, the new unit ships on Wed, the seller threw in the vette axles, this will help in the axle design.
Ithink i have a final design for the torsion tube, but will install tt on the weekend and see. I think 2 bushings one on each upright, and i think i should be able to have a removeble bottom cross(under trans) member to truley have a solid mid section back in the tt, i would have to think there is some load at the point of mount for the trailing arm, where it will be split, should be darn good. I will post some pics when a few more things are done to the car.

Well the new complete Z 06 transaxle/torque tube has landed, heading to Neche ND to pick up in the am. Got luckey today and found a 2 piece bell housing, 150.00 plus shipping, they are shipping on Friday. Need to get a few more things, then i am going to take a week off work in Feb and get this unit in where it belongs.

On another note ,what would be the best brake master set up with hydro boost for the 993TT and babies for the rear. What clutch master will work best with the corvette unit. Been looking at the Tilton products but costly. Does everyone run the stock porsche unit, my car was cable. Thoughts?

Well, the transaxle and TT are sitting in there new home, had to open the trans tunnel, but no biggy, from what i am finding in this change is, should be able to reuse some of the metal removed. QUESTION. does anyone no the measurement from the back of the floor pan ( behind torsion tube ) to the center of the porsche axles. I think i am with in a 1/4 ". Trans tunnel needed to widen 1", so out with the sawzall and cut the top off, and then split up the middle , add filler strip and reuse. Reuse the old trans hump, same deal cut up middle add filler and so on. I will post some pics on Monday. How long is a porsche axle, i dont have. splines on vette appear to be same as porsche, just slid my S2 hub on to the vette axle, will investigate deeper. TT appears to be about 5 to 7" to long cut and weld. Spline count anyone ?
Thanks in advance. Kevin.

Did GM lengthen the C6 driveline/TT?

[You must be registered and logged in to see this image.]
As you can see a little mods needed, but should fit like a glove. So far no surprises. This process will be a benefit with weight removel, and from what i see stock gas tank should work. I will test fit this week, but i think i will go to a different tank, i believe i should be able to have a tank sitting over the new trans, in fact i am going to try reversing the stock tank.Either way move the weight inboard and go alum. I will post more pics. Thanks, Kevin.

Good morning xschop, i dont know if they added length. I measure 54 1/4 ". On you car how close does the bell housing sit from the fire wall. You will see in the photos, how far the tt sits out.

[You must be registered and logged in to see this image.]
Here is a good look at the TT, my bell housing should be here this week.

If you are going to move the tank around, just make sure the axle outputs on the trans sit +/- 2 inch from the stub axles. The 930 Cv's can take alot of angularity. IIRC There is a bout 2 - 2.5" from C5 BH to firewall. I'll have to double check. I know that the driveline differences are only about 3/16 - 1/4" difference, so you will not have a problem in front.

EDIT: You're good to go there

[You must be registered and logged in to see this image.]

So, am i getting this right no shortning of tt, is that measurement from the face of BH our where it meets tt. The c5 shifter local is only about an 1" diff (back) from stock. Would you no the measurement from the center of axles back to vertical part of floor pan. If i can slide trans back a bit i will, but right now, i think i am within a quarter inch. If i dont have to shorten tt bonus. Does anyone have a pic looking in at the stock trans showing the output shaft area.Thank you.

In that pic, the rear of the driver's side head was 0.75" from firewall. Then I designed the 0.5" setback transmount which brought it back to 1/4" from firewall. You can mic your driver's rear head to block/BH interface and add 5.80" (C5 2 piece BH depth)

Run a stringline

xschop, thanks for the pics, it looks like the face of the BH is close to being inline with the fire wall, i cant measure head back, no motor yet, it comes with warranty and i dont want to waist. String line?

In the empty engine bay, run a stringline from left to right firewall where the brake MC mating plane is. I can get the head-to/block measurement for you at lunchtime or if someone has it handy step in...

Thanks xschop, had a brain cramp, yes straight edge across fire wall, on a 3/4" spacer to set on fire wall and measure back, i will do this tonight, i will also do a 1/4" spacer and see where that puts the trans and update. Thanks again. Work time.

I never took the measurement in yellow.... C5 driveline swap wasn't brewing at the time

You should be able to drop the drivetrain down as well......911 killa
I also just noticed the factory trans stop....that would be a great Purist slap-in-the-face if it could be re-used
[You must be registered and logged in to see this image.]

Thanks xschop. u are such a big help. I will check and see, crossing my fingers. How low does the stock trans hang? my trans is sitting about an inch or so below the 924 cross member where the fac trans use to hang. Does the drive line sit level or does it slope at all.Questions, questions, thank you.

The output shafts on the 944 trans sit 3.5" below the input shaft plane! So they sit right about center of the torsion tube and at normal ride height, the axles still angle down and forward towards the outer stub axles on the trailing arms. This is an audi box and only the input shaft is a different dimension...

[You must be registered and logged in to see this image.]

Thanks xschop, i will look into this tonight, would it not be so perfect if the tt can stay the same length. from the info you have provided, it looks very promising.

[img][You must be registered and logged in to see this link.][You must be registered and logged in to see this image.]47.s[You must be registered and logged in to see this image.]ervim[You must be registered and logged in to see this image.]g.com/u/f47/16/17/65/65/car_1-10.jpg[/i[img][You must be registered and logged in to see this link.]i47.servimg.c[You must be registered and logged in to see this image.]om/u/f47/16/17/65/65/car_1-14.jpg[/img][/url]mg][/url] Well in would appear that the C5 TT does not need to be shortened. I put a staright edge across the engine bay and a square hanging down. From the measuments i took i have room to move the drive train forward or backwards, this should be a really nice swap. You can see in the pics there is a 1/2" spacer between the straight edge and fire wall, all the adjustment needed.. My BH is in route, once here i will confirm, BUt this will work.

Now that's cleared up, you may have another issue. The shaft length is tell-tale as the C5 2-piece BH is shorter depth than the C6 1 piece by 0.75".....You may have to trim that shaft down or see if the C5 input shaft would work......or use the C6 BH

Or I could be wrong and you could use the factory Pilot bearing which sits much further into the crank.
What is the exact length of the splined edges to TT and the tip itself?

I will check tonight, but the C5 unit complete should be a perfect mate to the LS, it came from the factory this way, what am i not getting, the measurents i took should have the C5 BH sitting where the other BH sit when using the fac TT, and i do have movement front to back.

O.K. I re-read that you did get a C5 TT so the input shaft does insert into the factory recessed pilot and you'll have to use one of those. Big question, does the plane of the TOB seat sit flat with the plane of the TT/BH interface?......pic looks strange there too.

xschop, throw out bearing sits flat against tt, u can see in the pic the two small bolts in the middle of the tube, they hold the TOB inplace,the complete unit came with the vette tube, it should be as simple as factory GM parts. If i got the TOB abreviation right. The TT came complete, i took the TOB of for mock up. I will slide on and take pics.This should be one mean beast, with fuel milage.

Hello all , just to clear up any confusion, i am installing the complete Vette C5 Z06 drive line, motor to transaxle. All GM Porsche. Killer reliable power and balance a fine combo.

I know this is a part later on in this conversion, but I have been wondering what u will do to get the 944 rear hub to mate with the corvette trans hub? Custom shafts? Or something else?