Congratulations to Skip on the selection of his Miata-powered Caterham as the January Miata of the Month!
I have been tracking my '92 Sunburst yellow Miata for about 8 years and have been fighting an overheating problem on the track due to the amount of heat produced by the turbocharged 1,900 cc engine and intercooler. At a Peak to Peak Miata Club track event at the Aspen race track in October of '05, I had come to the conclusion that running at Colorado’s altitude and after all the different radiators (5), coolant reroutes (2) and other things I had tried, that I just wasn't going to be able to lick the problem. I decided that I was going to retire the Miata from the track and begin looking around for something else for a track day car.
That same day, I had a chance to drive a Caterham SV at the track, brought there by Ben from Rocky Mountain Sports Cars of Denver. The SV model is fairly recent and is 4” wider and 3” longer in the cockpit. This allowed space for my size 11 ½ wide feet to be able to work the pedals without hitting two pedals at once.
I went out as a passenger for a few laps and then Ben was brave enough to let me behind the wheel. It was a gearhead's epiphany. I have driven a number of cars on race tracks, including a twin turbo 911, a Ferrari 360 Modena, numerous Miatas from stock to wild and others. Nothing came close to this Caterham SV. It was almost telepathic; think about clipping that apex just so, and it happens. I was having so much fun they tell me I was laughing like a maniac all the way around the track. By the time I got out of the SV, I knew I had to have one.
I hadn't really planned on buying one right away, but I couldn't resist searching the internet to see what was available. I found a few SVs but one really caught my eye. The price was not listed but the ad said to call for a special price.
I talked to Rex at Speed Classics in Cottonwood, Arizona about the Laguna Seca Blue SV he had advertised. The car had been assembled but didn't have an engine or transmission, exactly what I was looking for. The "special price" turned out to be a screaming deal and after securing a quick second mortgage on my home I made arrangements with Rex to pickup the car.
Most late model Caterhams are built with Ford Zetec or Duratec engines. Since I am more familiar with Miata engines and their modifications, I decided to use a Miata engine and 5 speed transmission.
I immediately began looking for a donor engine and transmission. I bid on and won a low mileage 2000 Miata at the local salvage auction. After trailering it home, I disassembled the car, right down to almost the last nut and bolt. Only the gas tank and fuel filter were left on the hulk when I took it to the crusher. The remains weighed only 460 lb. Selling the extra parts on the Miata.net classifieds recovered the cost of the salvage Miata and left me with a free engine and transmission and some cash to put back into the build budget.
A damaged transmission was found to experiment with and a significant amount of metal had to be removed from the tailshaft housing of the transmission to allow it to fit into the very narrow transmission tunnel on the Caterham. Once I had hacked, ground and filed it to fit, a friend used that tailshaft housing as a template and machined the tailshaft of the 2000 transmission to fit and also machined an adaptor on the bottom of the housing to accommodate the standard Caterham transmission mount. Bill Cardell of Flyin Miata loaned me an empty 1.8 engine block, pan, head and manifold to use to mockup the engine and transmission mounts. Once the altered transmission was in place, the mockup engine was installed and engine mounts were fabricated.
The rest of the installation was fairly simple except for merging the Link ECU and a ’96 Miata wiring harness into the pre-wired Caterham chassis. This was the most difficult part of the project and over 80 hours were spent on the engine wiring. To my amazement the engine started on the very first attempt. There is a short video of the startup on YouTube.
Once I had a car that could be driven, I began the process of getting the car through the DMV licensing process. The requirements for kit cars are quite different from normal cars. I had to trailer the car to the highway patrol station in Golden for a physical inspection. I was warned that this could be as difficult as having everything checked and even tests like measuring the heights of the headlights. Some people have had it very difficult. The two vehicles in front of me that day were both rejected. I had it easy, the only thing they had me do was start the engine to hear how loud the exhaust was. Then I had to provide documentation proving the major parts I used in the build were not stolen. The officer inspected the VINs on the car and the engine.
With a large folder of paper work I went off to the DMV to get it registered. I was pleasantly surprised when I was issued plates with no hassles. I got home and about an hour later was in the process of mounting them on the car, anticipating my first legal drive in it when the phone rang. It was the DMV informing me that they had missed a step and I would have to bring the plates back. Another six weeks and another trip to the highway patrol to get a new VIN plate attached went by before we got things straightened out and the plates were issued.
The Caterham is a dream to drive, it is as elemental a sports car as you can get. With 235 RWHP and weighing only 1,340 lb. it is extremely quick and has the handling and brakes to go with it. It has been to five track days and now has about 2,000 miles on it. It even won its class in the concours at the 27th annual Lotus Owners Gathering (LOG27) held at Snowmass/Aspen this past August.
The project took about 1 year of my spare time and now I have the bug to build another car so I’m looking around for this winter’s project.
A more detailed documentation of the build can be found at CarDomain.
Will you be next?