A couple of friends and I have come up with a design for a rear shock tower bar for our cars. After a few brainstorming sessions and some reasoning we came up with what you are about to see. Yes, it looks a lot like one that is already offered, but is MUCH more affordable. We also have some results from testing we did.
I also wanted to say that it was NOT our intent to copy anybody's design. Yes, this particular design is very similar to the one currently on the market, but it IS different. This one is longer, uses 2 bolts at each end instead of 1, and is made of different materials. The current one is also MUCH more expensive!
If we were to make these it would be $40 plus shipping, and that would include the bar(it will be sanded down and primered so the customer can paint it the color they want...I'd suggest doing this AFTER the bar is installed if you intend on reinstalling the rear panels), the attatching hardware, and instructions. Because these are the first few there would be a lead time for the first batch. If somebody is interested they should contact either me or "slowbrokedodge" via e-mail or PM(e-mail is better for slowbrokedodge).
We tested the prototype bar in an '86 Daytona Turbo Z that is being parted. The doors were not latched, the hatch was completely off, there was NO interior when the tests were done...oh yeah, and it is a sunroof car at that. So basically it was about the worst case scenario we could duplicate for chassis flex to see how much the bar could help. The car was on four jackstands for the testing.
It's kind of hard to describe where the test points were that we used for measuring. There was one at each corner of the hatch opening to check for squareness, and then there were four more under the car at known chassis points to the ground to see if the other part of the unibody was also affected and to make sure we were putting the same stress on the car.
The numbers look like this:
Control-no jack: The hatch opening was 70" and 69.5" across it diagonally with the car static, we had not touched it at this point. The four chassis points were mearly for refference, their numbers don't really mean all the much.
We then jacked the car up on the left rear spring perch on the rear axle to best simulate road conditions. We lifted the car 3" past full suspension conpression.
The results without the bar are as follows:
69-1/2" and 69-3/8" (compared to the control 70 and 69-1/2) across the respective diagonals on the hatch opening. The total deflection: 5/8"
The results WITH the bar are as follows:
69-5/8" and 69-1/2" (compared to the control 70 and 69-1/2) across the respective diagonals on the hatch opening. The total deflection: 1/8"
We then tested with a currently available bar that is made by a vendor from our community. This test was done on a different day and the car has slightly shifted, hence the slightly different control numbers. The numbers for the chassis refference measurements were taken and were the same. The results from that test are as follows:
69-3/8" and 69-3/8" (compared to the control 69-1/2 and 69-3/8). The total deflection: 1/8".
Our conclusion is that the bar makes a significant difference in the deflection of the superstructer of the unibody. Apon driving my car with the bar installed I noticed the car no longer made a lot of creeking noises from the hatch area, the "boominess" was greatly diminished over rough roads, and the car handled almost neutrally around hard corners with a stock suspension.
This is how it looked installed in the test car:
This is the same bar installed in my 1988 Shelby Z. Keep in mind this is the very first one we made, the design is still being perfected.
This is how the bolts fit. The outer one is VERY tight, but it does fit. An open end box wrench is needed to hold it for sure!
This is the bolts from under the car so you can see where they are. Once tightened they do sit flat against the body. We did end up trimming the bolts off. These were 2" grade 8 bolts, nuts and lockwashers. I also used Grade 5 flat washers because they were larger in diameter than the Grade 8 ones.
This is the bar completely installed in my car. I painted it the closest color I could find to the interior. One of the major factors involved with this design is that my subwoofer HAD to fit under it and it had to fit under the tonoue cover. It was successful!
TurboDodge.com 
