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Unread 08-20-2015, 02:45 PM
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Default Re: Vorshlag Build Thread - 69 Camaro Pro Touring/Track Car

continued from above

Watts Link and Aluminum Center Section

Many of the Watts Link parts were re-used in the new layout, shown below. The mounting tabs were super sketchy before, and looked like they'd fold up under hard cornering. These new mounts are stronger and will receive additional bracing and structure as the build progresses.

The solid axle had the mount for the center pivot of the Watts, as you can see above left. It was a decent looking mount and double-shear style football pivot, so those pieces were re-used. Since the rear frame rails and mounts for the Watts link changed, we had to alter the length of the lateral arms for the Watts. So those went from steel to aluminum lateral locating links; the old pics show black arms which are now gold anodized and adjustable length.

Next up was ordering the "third member" or "pumpkin" (rear gears + limited slip + bearing assembly) that bolts into the front of the Ford 9" rear axle housing. The housing was bare when the car rolled in here, so Ryan shared different available third member brand and material options with the customer and in the end we chose a Moser aluminum center section. Normally these are cast iron (nodular iron) but the Moser built aluminum third member is much lighter and plenty strong. Gearing calcs were done to pick the rear gear ratio that worked with the tire height (345/30/19 Hoosier), the gearing from the G-Force trans, and terminal speeds we expect the car to see at Texas road course tracks.

There are a lot of differential options for the Ford 9" but we chose a WaveTrac. We needed the third member in place to be able to know where to make room for the driveshaft, exhaust and such. Having Moser build and supply the entire assembly made it easy - they installed and setup the hypoid gear set, bearings, and differential into the aluminum housing - so that can be just bolted into the axle housing. We picked up some ARP studs and nuts for a Ford 9" housing and installed the third member shortly after it arrived (below).

New Front Subframe Fab

By now we are into work done in early to mid June. After the old front subframe was removed, additional 2x4" frame rail material was purchased. Ryan got to town and had the new rails cut and tacked in place quickly and began the front suspension mounting points.

The suspension used of a lot of pre-existing parts, including C6 Corvette aluminum uprights, aluminum C6 upper and lower control arms, and big disc brakes from Wilwood. There's a fabricated steering arm on the spindles, which was for the old subframe and rack setup. There was a haggard looking Fox Mustang steering rack kluged into the old subframe, but we knew that had to go (more on that next time).

Please note: all of the lower control arm mounts WILL be double shear. They are incomplete in the image above

Since we had other ideas for a more appropriate steering rack, Ryan left out some of the front structure - awaiting the new rack. As you can see the front has room for a bolt-in lower brace structure, which should allow for track-side service of the oil pan with the motor still in the car. Its a dry sump oil oiling system and pan, which still allows the motor to sit fairly low. The C6 control arms were mounted after geometry was again checked in simulation and placed where we could get some real camber and alignment settings appropriate for track use.

Again, the previous plate steel mounts were cantilevered off the frame rails and looked like they would not withstand the side loading that 315 Hoosiers could generate. We asked Ryan to tie the upper control arm mounting plates into the frame with tubing. The curved tubing wraps around the mounting plates and vertical 1-3/4" tubing will come up and tie across the engine bay. This will also be tied back into to the roll cage.

Before too long the motor and transmission needed to go in to make sure the front subframe frame rails left appropriate room to add custom full length headers (will show the construction of the headers in my next post). The placement and driveline angles were checked and re-checked then Ryan began working on the motor mounts. The driver's side mount is already installed in the image above, and you can see the digital angle finder on the tail of the G-force transmission as well.

The motor mounts use the same Energy Suspension polyurethane bushing we've used on hundreds of LS swaps, which is both rigid enough to prevent drivetrain deflection but just supple enough to cancel out some NVH. The mounts tie into the front frame/subframe structure and bolt on.

Above you can see Brad and Ryan test fitting one of three different racing seats the customer brought - a Sparco EVO III, an EVOII, and a Lajoie aluminum seat - which I will show next time. They also mocked up a driveshaft with 4" PVC tubing, to check rear crossmember clearance and tunnel position. There's some floor and tunnel structure started here, but I will show more of that in my next post.

A quick body mockup showed that meeting the desired engine setback would be easier to remove the factory cowl in favor of a fabricated part rather than just trimming it. Again, the firewall had been heavily modified (and yet had zero room for exhaust headers) and the rusty cowl was a mess, so losing all of that wasn't making anyone too sad. Plasma cutter made the initial, big cuts on the cowl, then the body could slide down over the chassis to verify fit...

With the body on you can see the engine setback clearly, above. The Norwood "alumi-fit" 69 Z28 reproduction aluminum front fenders and hood were also test fitted at this stage, to check basic clearances to the engine, tires, etc. Everything looked good and fit as expected.

That shot gives you a better image of what the car will look like when its done. It looks SO much meaner with the wheels and tires fitted, but I will show that next time.

Videos - This Week At Vorshlag

The 69 Camaro has made it into a few of my semi-regular "this week at Vorshlag" videos, and the one below get us caught up to where we stopped here in this build thread.

This June 15th Video has plenty of 69 Camaro at the beginning to about the 3:38 mark.

What's Next?

Next time I will finish covering the rest of the work knocked out in June and then some going into July, including: the differential install, more floor structure and tunnel fab work, dry sump tank mounting, more front suspension work, and firewall structure work. Oh yea, and the roll cage was built (teaser pic above). Until next time...


Last edited by Fair!; 08-20-2015 at 03:11 PM.
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