Street Stock Chassis Build up Part 2

Jim Ott

 

In the continuation of the Street Stock chassis build we need to focus on the reassembly of the chassis components and the main shell of the body. In the previous segment we looked at preparing the main chassis by re-welding all joints and making any necessary repairs to the frame. We are going to look at the finishing touches on the frame and plan to do a mock-up of the front suspension, steering components and rear differential and suspension.

 

We built this car to race at a little 1/4 mile track called Varney Motor Speedway located in Ontario Canada as my driver was only thirteen years old it was tough to find a track that would let us run. The rules at Varney are somewhat unique and in the Street Stock division don’t allow too many changes. Bearing that in mind we will look at everything we can do and still remain legal.

 

 We finished off the frame by boxing in the long section between the front and rear clips. The formed channels the GM installed are barely better than sheet metal and if you ever tried to jack your car up in this are you know what I mean. I believe that this is a safety item and boxing the frame in gives me a stronger sense of security for my son’s well-being out on the track. As our rules book states a “stock frame”, I decided not to get carried away the boxing idea and trying to jamb in the heavy tubing you might see in other divisions. The material we used was very close in thickness to the rest of the frame and we merely bent it to form around the humped areas of the middle body mounts. This gave the frame a nice neat “stock appearing” look and hopefully will pass the tech inspectors ever watchful eye as our intended safety improvement. The plates were cut to cover the upper fold and reach the bottom flanged. We ran them from where the front clip ended to where the rear clip began. At the clip ends we installed small pieces to cap the OEM openings to give us something to tie the plates to. Our shop double duties as a fabrication shop which recently picked a new MIG welder so we were able to lay down some nice beads to hold in the new metal work. The plates were continuous bead welded in on a slight angle to pick up the factory stamped contour leaving plenty of room to run the fuel and the brake lines.

 

The next task at hand was to prepare the suspension components for reassembly. The control arms were sandblasted and after we removed the bushings they were then given a coat of paint. I tried a few different methods of removing the bushings and settled on using the ever-trusted oxy-acetylene torch. This proved to be very fast at releasing the rubber, but not without a wonderful show of shooting smoke and flames. PLEASE be very careful using this method as you could be easily be burned if you are not mindful of the micro explosion of rubber and flames as the bushing gets hot. This is also best done outside as the burning rubber gives allot off nasty smoke. The remaining tubes had the center sections cut out and we used a hammer and chisel to collapse and beat out the left over tubing stubs. This is the point where I would have liked to said we spent a boat load of money on urethane suspension parts but due too our strictly enforced stock rules, the truth is we loaded aftermarket rubber replacements in the arms. If you’re working on a GM metric chassis you will already know the suspension pivot bolts are metric and can be a little difficult to find. I gave this allot of thought about over sizing the holes to install 1/2” hardware and even tried to drill out the stock bushings. This proved to be an utter waste of time! The inner sleeve of the new suspension bushings are formed metal tubes with an un-welded seam. The drill will go in and just get stuck without actually removing any material! It seems the tube opens up to allow drill bit in and nothing happens except the drill gets really hot. Oh well those stock suspension bolts look like they will do the job just fine.

 

 

 

The suspension components were all assembled back into the frame for a test fit. We left the springs and shocks out to be able to fully stroke the suspension to check for binding or any interference. The control arm bolts were installed with plenty of Anti-Seize as the lubricant because we are not going to tighten them up as they were originally installed. What we want here is the bushings to pivot around the bolts. They were tightened just to provide a slight drag as they were moved up and down in there travel. All the components were re-fitted and test in the same manner. It’s worth noting here that all the suspension components in the front end were replaced with brand new parts. I don’t feel it’s really worth the hassle to replace worn out twenty plus year old parts half way through season when we can do it now. New premium ball joints were fitted in the upper and lower control arms. Again our rules dictated stock parts for the make and model year be installed, but it doesn’t say we have to use the cheap stuff! We also did a test fit for the rear suspension and the differential. If you recall in the first segment we did allot welding in the rear and I wanted to make sure we didn’t bend or warp anything. It all seemed to go very well and having the rear end installed for the time being gave us the opportunity too move the car around on some wheels. All new steel brake lines were installed on the frame along with the original proportioning valve as per our rule package.

 

Preparing the body for race use has to be about the most miserable job of all. My son Jake did a wonderful job of attacking his new race car with a grinder fitted a wire wheel to remove all of that wonder seam sealant that covers a car. When the welding begins you will appreciate having this done before hand as it becomes very apparent that some got missed when you start inhaling the resulting acrid smoke. We had to replace the entire driver side floor pan as it had completely rusted away. I opted not to buy the rust repair panels available at your local parts store because I can fab them myself and I would rather spend the $375 dollars they cost somewhere else. Some 20GA. sheet metal did the trick for the floor as well as the fire wall patches. 22GA. Is far easier to work with but for these areas I like the patches to be a little thicker. Speaking of firewalls, we took allot of extra time in this area to make sure the patches were all fitted properly and completely welded in. In our first season we had a small oil fire and I want to make sure my driver is well protected by having a sound firewall free from holes. After trimming away all the unnecessary tabs and mounts we went ahead and painted the firewall before mounting the body. It will undoubtedly get messed up but with the tractor paint touching up is relatively easy. We used our ever handy engine hoist to position the body over the frame and to suspend it while we positioned our NHL official body mounts (a.k.a. hockey pucks). After getting the mounts and body into position we are now ready to bolt it into position.

 

With the main body shell in position we are starting to get a sense of accomplishment. It has been allot of work until this point and the car still looks nothing like a stock car. At this point Jake was able to finish off some floor patches and to do some more trimming of unnecessary junk in the car. He has all  the seam sealer and tar removed from the trunk area and in the cockpit of the body. This will give the car a nice professional look when everything is painted.

 

 Jake and I also have to keep up with paying the bills so we need to get some much needed fab work out of the way and free up some valuable shop space. In the next segment we are going to begin the task of installing the roll cage and getting the car to a state where it begins to resemble a race car! The CSC (http://www.cscracing.com/index.html ) roll bar kit uses the front spindles as a reference point for installation so this is another good reason to have the front suspension mocked up.