The
Next Step – Our chassis takes shape! |
We left our project with the roll bar hoop attached to the chassis rails. The next job on the agenda is adding the outboard floor bars, on this chassis the bars are about three inches off the ground. The drawings show the bar parallel with the floor but you may need to alter that if you are going to run mufflers and need to tuck them under the floor. It is quite OK to raise the front bars and have the floor running at an angle, many Pro cars are built this way. This is a case in point for looking at the big picture and having a good plan for your chassis build. Remember the chassis has to accept your running gear and the time to make any changes is before you complete all the welding. Another thing to keep in mind is the fact that all drag cars will probably have to run mufflers in the next few years. Track owners have to consider noise pollution as one of the problems they have with the surrounding communities and mufflers are a concession they can offer to appease irate neighbors. If you build your chassis to accommodate mufflers now, you won’t have a problem if you are mandated to have them. The roofline bars are the next on the list. Both bars are shipped with extra length and will therefore accommodate any changes in position of the floor bars. Using the digital protractor you make sure the bars are parallel to the ground and rotated to the proper angle to ensure a good fit with the windshield pillars. The bars are tacked in place and the brow bar and dash bar cut to length before fitting to the chassis. At this point it is best to test fit the cab to ensure a proper fit without interfering with the chassis. All required braces are listed in the Morrison instruction manual along with their diameter and wall thickness. Once the main cage is complete the next step is to install the strut bars. Morrison provides angle iron to fabricate a support frame to properly locate the strut bars ensuring they are in the proper place for locating the upper strut mounts. The strut support tubes are only tacked in position until the headers have been constructed. The front motor plate support bars are not included in the kit and are required to be bent up out of tubing. When you position the support bars you have to remember that they set the width of the motor plate. Too narrow and you have not enough space to mount ancillary equipment and too wide will not help with the fore-aft location of the motor. You have to have some sort of support for the motor plate to hold it in position while the motor is being bolted into the chassis. Most chassis builders fabricate a combination of flat plates to support the motor plate, I decided to fabricate a support using tubing. The motor plate then has a half round notch which locates the plate, this is similar in design to the type of plate that is used in twin rail chassis as used in Pro Modified cars. A truck chassis differs from a car due to the extended wheelbase of the truck. This is reflected by the addition of a four link box that moves the four link brackets back seventeen inches from the main hoop. The bars in the rear of a truck chassis also differ from a car due to the need to cover them with bed cover. The only bars visible are the main hoop supports, which exit through the rear window area and reattach themselves to the chassis through the bed tonneau cover. The rear of the chassis is fairly straight forward, as it only has to attach the rear shock absorbers and provide somewhere to attach the body. In our case we want to make the bed sides removable to facilitate removal of the rear slicks. To do this we fabricated a substantial removable frame to attach the tailgate and rear wing to, which gives us something solid to attach the bed side framework. Unlike the Pro Stock trucks, which raise the bed and modify the cab to give more tire clearance we are sticking with the factory look and appearance. This could cause tire clearance problems but we hope to get around that when we mount our new Mickey Thompson slicks and see what room is available. If there is a problem we will integrate a rear spoiler into some clearance humps or rake the body to give us the clearance needed. This is another case of having everything available to you before you start building your racecar but like most racers that are building a vehicle themselves you tend to do it on a budget and purchase components over a period of time. I would suggest sitting down and planning out your build process and deciding what parts are required for what section of the build. The next issue will cover the fitting of the rest of the components that make up a racecar. Make sure you check it out!
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