Here it is, our new 2003 Civic Si demo car project. It's stock right now, but not for long.
Sometimes, you just know that a project is going to be special before you even get started. Ideas that have been floating around in your head for years will finally get a chance to be created in three dimensions for all to see. Chris Yato and I had discussed a project of this magnitude for quite a while, and 2002 was the year that the car, the budget, and the time all came together to allow us to get it done. Without further delay, I present to you our 2003 Honda Civic Si demo car.
The main concept behind this project was to have the driver be totally enveloped by the audible and visual impact that the product and the installation created. To do this, the first thing we had to do was put the driver physically in the center of the action. As such, we had to create the world's first center-drive Honda Civic. Once the smoke from the welder and the plasma cutter had settled, a month of labor produced a working center-drive mechanism. Let's take a look at how we did this, step-by-step.
This is what the dash area looks like from the factory, complete with the dash-mounted shifter.
We took delivery of our new Civic in early July, and it remained stock for about one day. After snapping some "before" pictures we proceeded to entirely strip the interior of the car. At this point, we realized how good of a job we had done at selecting a car for our intended purpose. The floor of the Civic is almost entirely flat, with no center "hump" running down the middle. This makes putting the seat there a whole lot easier. The only minor thing we noticed was a small hump near the base of the firewall, where the catalytic converter came off of the header. Since this was a vehicle that was strictly for show, we decided to eliminate the converter, along with the rest of the factory exhaust system. The car now has a 24-inch dump tube coming directly off of the header, so it really gets noticed when we roll it into a Hot Import Nights show!
With the converter gone, we could now cut out the hump in the floor. We used one of our favorite tools, the plasma cutter, to do this quickly and efficiently. The plasma cutter basically heats up the metal near its tip to red hot, then blows it out of the way using compressed air. Needless to say, it creates a spectacular shower of sparks, so you have to be careful with it. It only took about a minute to cut out the hump, leaving a very clear view of the ground. We then fabricated a 20-gauge steel plate to replace this floor piece. Notice the holes in the edges of this panel -- they will be used to weld the sheet metal to the floor. You can't just weld thin metal continuously, because the heat created by this process warps it badly. By welding only through the holes, the panel is secured while not distorting its shape. The only problem with this technique is that the floor is not sealed against moisture. Fortunately, 3-M makes an epoxy called Panel Bonding Adhesive that is designed to adhere metal together. We used this epoxy to seal the edge of the floor plate, which also made the joint much stronger.
Now our floor was completely flat, so it was time to start the center drive conversion. The first step was to create a mounting bracket for the pedal assembly and the steering column. The biggest challenge here was how to move the brake and clutch master cylinders so that the pedals could act directly on them, just like from the factory. To do this, we decided to move the seating position back approximately 20 inches, allowing the master cylinders to be relocated to the inside of the car. We also ran hoses from under the hood to the inside of the car, allowing us to retain the factory filler reservoirs for the brakes and the clutch.
Once the pedal assembly was completed, it was time to get it in the car. A few well-placed brackets were bent and then welded to the assembly, allowing them to be bolted to the stock firewall. The master cylinders can also be seen here, behind the pedal assembly. With the pedal assembly positioned in the center, the steering column could now be clamped and welded to the top of the structure. The gas pedal was the easiest part, since the cable length was perfect, so we simply welded the pedal structure to our existing piece and clipped on the cable.
The last step for this project was to get the steering to work properly. The Civic has a steering knuckle that passes through the firewall on the driver's side, so we had to mate this piece up with our relocated steering column. To do this, we cut the stock steering rod in half and extended it by 18 inches with a piece of tubular steel. The joints were then welded and ground down to make a solid piece. We had to trim away some edges on our steering column brace to allow the steering rod to pass through; we were then able to connect the two sections with the newly formed rod. The stock U-joints on both sides of the rod worked well to translate the motion of the steering wheel smoothly to the stock steering system. At this point, the brakes, clutch, gas pedal and steering worked flawlessly in the middle of the car.
The first step was to completely gut the car, including the dash, heater, A/C, steering column, and pedal cluster. | 
Our single-seat idea requires the floor to be flat, so this hump in the floor has to be removed. This is where the driver's feet will go when the car is complete. | 
There's nothing that cuts metal faster than the plasma cutter. Here's me cutting out the hump. |
Wow, that's the ground down there! The hump's gone, and now we can fabricate the flat plate that goes over it. | 
The replacement floor plate was cut out of 20-gauge steel with the plasma cutter. We then drilled holes in the edges to weld the plate to the floor. | 
The plate was placed on the floor, welded through the edge holes, and then sealed with body panel epoxy. |
The next step was to fabricate the mounting structure for the pedals and steering column. Here's Chris welding the assembly together. | 
This is where the master cylinders for the brakes and clutch were originally mounted, on the engine side of the firewall. Our design moves both of these inside the car, while still using the stock reservoir locations under the hood. | 
Here's the pedal assembly mounted in the car. The large, round, black cylinder is the brake master cylinder, now mounted inside the firewall. |
With the pedal assembly in place, we modified the stock steering column and bolted it to the top of the structure. | 
The gas pedal was the last one to be mounted. Fortunately, we were able to retain the stock throttle cable and re-run it. | 
The last step was to make the steering work. We cut the stock steering rod in half between the U-joints, then extended it 18 inches with a tubular steel section. The ends were welded on each side of the tube and the pedal assembly was clearanced to allow the rod to pass through. |
Next month, we'll talk about the shifter and emergency brake assembly, along with the building of the seat itself. Check out www.SteveBrownUniversity.com for some unique opportunities to get hands-on with some of these techniques, and keep those questions coming to sbrown@alpine-usa.com.