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As I mentioned earlier, the rear suspension will be completely scratch built using an independent Short Long Arm (SLA) and trailing arm style. I wanted to utilize a modern wheel bearing instead of the heavy Corvair unit. To keep things simple-ish, I chose to use the wheel bearings off the front of a Pontiac G6. This way the axle splines will be matched to the transmission when that time comes. I also decided to use the disk breaks off the front of a G6, which are massive and should work really really well. A trip to the junkyard got me the cores I needed plus the aluminum hub that is not available at the parts counter.









I took these aluminum castings to the mill and removed all the strut and ball joint mounts, as they will not be used.

I purchased brand new USA wheel bearings, calipers, and cross drilled and vented rotors. I then pressed the metric studs out of the wheel bearings, redrilled them for the 5 on 4.75" Corvair lug spacing, and pressed in 7/16-20 studs so I will have an excellent choice of wheels.

During the Christmas break I had a little time to do some research. I wanted to get a grasp on the axle situation because I knew it was going to be a tricky one. The benefit of using the G6 wheel bearing hubs is that I could use CV joints instead of u joints. The Pontiac G6 has a 30 spline hub, just like most 2001ish and newer GM cars. The F40 transmission has a 27 spline internal. Since the G6 GTP with a manual is such a rare beast, if it even exists at all (I mean who would really want to have to shift gears) I knew there was no way I was going to find the axles anywhere. After a few days of web searching, I found that 2003+ Saab 9-5 cars have 30 spline hubs, and use the same transmission splines as the F40! They also have the intermediate passenger side axle shaft that is not available when purchasing replacement axles. A trip (well 3 actually, but that story could have its own thread) to the local pick and pull and I had axles. They are too long, but upon disassemble I found that the inner shafts are not terribly hard and I will be able to put them in my mill with an indexer and will be able to shorten and respline them to fit my needs!

I wanted to have 4 bucket seats for this project, so last summer I went to the local pick and pull and bought 4 identical Dodge Neon seats. These will work very well.

So that pretty much brings us up to speed with where I am at right now. My next task is to finish the rear suspension. Right now I am building the trailing arms out of 9 gauge sheet metal. I had a buddy with a press brake bend bend 2" flanges to form a U channel. From here I will cut and bend and weld the shape of the trailing arm.

For the front of the trailing arm I bought spherical bearings and machined hubs to fit them. I will post more progress as I get it done!

Work continues on the custom trailing arms, I have made all the bends per my CAD drawings, and hopefully today I will have time to cut the holes for the front bearing sleeve and for the wheel bearing mount.

I have been slowly building rear suspension parts for the GTP Corsa, the new custom rear trailing arms are nearly complete, I just had to verify a few clearance areas and then I will box them up for strength. I have redesigned the rear locator arm attachment area since this photo was taken, I did not want to rely on the shoulder bolts to carry the shock load of the locator arms so I have cut away that .750" thick block and have moved the locator points inside the trailing arm for strength. Kinda hard to explain, the pictures I hopefully will have in the next few weeks will tell the story a little better.

Finally figured out the ideal mounting points for the locator arms, as well as their ideal length. I used http://www.vsusp.com and it is a wonderful free program. Once I had my numbers I designed a center mount bracket and cut it out with one of the CNC machines at work. It would have been quicker to plasma-cam or water jet this out, but hey, the CNC time was free. I made this out of 2 pieces of 10 gauge sheet steel that I bought used, hence the orange powder coating. After they were cut out I sand blasted the paint off to weld.

Last night I had a chance to mock up the rear suspension a little bit, and check a few clearances, things are looking pretty good! Now that I feel good everything will clear, I will get the trailing arms welded up completely, and then start figuring out the coil over shocks and how those will mount.

Got things mounted a little better, everything seems to clear nicely. Now I need to decide how and where I am going to mount a coilover spring setup. Then I need to determine what spring rates I need. After that I can shorten the CV joints, and box up the trailing arms. That should pretty much wrap up the rear suspension! Then onto, well I guess I am not sure what I will move onto next, maybe the cooling system. Stay tuned!

Ryan,

This is progressing into a great build book. You should be very proud of what you have accomplished to date. Others should be encouraged by your project enough to put their plans in motion.