Exo Car “Ghettocet” Build Guide Part 11: Building the Front End

The NA Miata came to me with extensive front-end damage, so much so that the frame rails forward of the front struts were cut. Although I am getting closer to painting and reassembling, I must first construct a front end. I will create a tubular front bumper that ties into the front frame rails and strut mount reinforcements to stay aligned with the build. The focus is to make this front bumper as short as possible while protecting the wheels and engine compartment.

Considerations and Taking a Step Back

Before undertaking the last major fabrication of the ghettocet build, I had to take a few measurements and make one big decision. Namely, I forgot to measure the distance from the front frame to the front sway bar. I need to construct sway bar attachments along with the bumper. To get this measurement, I separated the engine from the front subframe. I then reattached the subframe and front suspension to the chassis. This allowed me to take measurements and verify placement as I constructed the front.

Using four tow straps as a lift to raise the exo car chassis high enough in the air to slide the front subframe under.
I used my DIY ‘lift’ again to raise the chassis enough to slide the subframe underneath.

As for the big decision, this project is an ideal test bed for me before another, larger build. As such, I decided to mount the radiator in the rear. I came to this decision for numerous reasons. First, this car will see serious track time, and the radiator will be entirely exposed without a front end. I thought about building a protective screen, but as I got into it, I started to like the idea of keeping the front end as short as possible to complement the rear. Second, this will ultimately leave the engine area completely open to whatever I want to throw at it. (turbo, intercooler, water injection, etc…) And finally, not only do I need to get a little more weight to the rear, but I think a rear mount radiator on an exo car is going to look pretty damn cool.

Fabricating the Front End

The build process was pretty straightforward. I attached two forward bars to the strut tower plates I had previously built. Then, I ran a bar perpendicular to and between these two bars right in front of the sway bar plane. Two drop bars were added to bring another horizontal bar in line with the sway bar. This lower bar is then triangulated to the front bar that was run across the end of the initial forward bars. Finally, one bar per side is run at an angle from the forwardmost bar back to the bars that attach the strut reinforcements to the main roll cage. This creates a stout, triangulated forward bumper that fully supports the sway bar load with no flex. (the pics below should make it clear)

The front end reinforcement plates on the 1991 NA Miata front end.
The forward bars attach to the reinforcement plates, which I had the pleasure of doing twice during part 9.
The front bumper frame of the ghettocet miata exo car.
The tubular front bumper. The forward-most bar is the bumper, and you can see the lower bar the sway bar mounts will attach to. Everything is triangulated to the cage and frame.

Sway Bar Bushing Attachments

To attach the sway bar mounts to the ghettocet, I cut and formed two mounts out of 3/16″ steel. These are rectangular plates with two holes drilled in them. The upper holes have bolts inserted due to the upp clearance to the bar. These bolts were welded in place, and the backs ground down before. Then the plates were attached to the sway bar and welded in place.

Sway bar mount plate for the ghettocet miata
The base of the mounting plate is a simple rectangle cut out of 3/16″ steel. Two holes are drilled to mount the bushing bracket.
The bolt welded to the sway bar bracket for the Miata ghettocet.
Before and After. Due to clearance, the upper hole of the bracket has a bolt welded to it from the other side. The back is then ground down to 1/16″ to keep a strong weld but eliminate excess material.
The sway bar bracket is now attached to the front bumper system on the exo car miata.
Here, you can see the bracket attached to the lower bumper assembly.

Next Steps

I only have three items left in the fabrication phase. Weld a crossbar to the roll cage rear to mount the radiator, attach the side window net mounts, and build and install the window and roof frame. Then it will be painted, and I can start reassembling this thing and finally get it to an event. (I also need to figure something out for wheel wells so the exo car will be legal for wheel-to-wheel racing.)

This time lapse starts with me cutting out my previous work after I decided to shorten the front with a rear mount radiator.

By Chris Simmons

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