June 16, 2007

I decided to go with an intercooler right from the start instead of going with low boost and no intercooler and adding it later. I found an intercooler from Track Dog Racing that met my needs and fabricated the plumbing from 2 1/4" exhaust tubing and Samco silicone hoses. It all fits inside the nosecone although the 90* silicone hoses touch the underside of the nosecone. I sanded the areas smooth and will consider the hoses to be consumable items to be replaced as necessary.

The turbo is mounted on a cast manifold from Flyin Miata. I made a small sleeve to attach a K&N air filter directly to the intake of the turbo.

The electronic boost control valve is mounted to the engine and plumbed between the turbo compressor outlet and the wastegate operating can. The Link ECU controls this valve which bleeds off pressure going to the can to allow higher boost levels than the base value of the can.

Hanksville Hot Rods fabricated the down pipe and the side pipe as well as welding up the cat, muffler and tail pipes. The downpipe started with a flange with an internal divider between turbine outlet and wastegate outlet from Corky Bell to which Hank added the two pipes making up the down pipe. The main pipe starts at 2 1/4" and steps up in two steps to 3". The wastegate pipe is 1 3/4" diameter and joins the 3" main pipe downstream just prior to where the 3" main pipe exits the side of the car. A 3" flange joint allows easy removal and installation of the exhaust system. The complete exhaust system is stainless steel.

After the muffler there is a splitter that converts the 3" main pipe into two 2 1/4" Caterham tail pipes which exit at the rear of the car. A heat shield has been added over the muffler to help prevent cooking my legs when entering and exiting the car.

The cooling system was completed using a pressure tank from Canton mounted on a bracket I bent up from flat aluminum. There is an overflow/recovery tank mounted in front of the passenger footwell, also on a custom bracket.

Things were coming together rather quickly and on April 17, 2007 the engine was started for the first time. To my amazement, it started instantly on the first attempt. There is a short video of the first start on YouTube. You can hear the sporty sound of the exhaust system.

There is a walk around video on YouTube that gives a better overall view of the nearly finished car. The car was driven for the first time on April 27th and a rather boring video can be seen here.

The car has been weighed and corner weighted. It came in at 1,371 lb with full weather gear, spare tire and wheel, jack and tool pack and 4 gallons of gas. Track weight without these items (other than the gas) should be about 1,325 lb. With an estimated 240 RWHP the car will have a power to weight ratio of 5.52 pounds per HP. It certainly feels very quick the few times I have run it up through the gears.

Front corner weights were spot on without me in the car, biased to the driver side with me in the seat. I remeasured the clearance under the oil sump now that the car is mostly complete and it has dropped from 3 3/4" to 2 1/2". I purchased some adjustable perches for the coil overs and when I install them I will raise the car back up to at least 3 1/2".

I have driven the car a few times on back roads and all seems to be working well except the electronic speedometer won't talk to the Miata speed sensor, the gas gage doesn't work and the alternator light stays on even though the alternator is producing the specified voltage and the battery is staying charged. These are all minor problems and I am working on them.

I am now in the process of getting the car licensed for the street. A somewhat complicated process here in Colorado as you have to deal with both the state and county goverments. No one person knows the whole system and I have had to jump through hoops several times. The first trip to the DMV went well and I had to make an appointment with the highway patrol to have a certified VIN inspection. This meant loading the car on a trailer and taking it to a highway partol station in Golden, CO. On my second trip to the DMV I was issued plates and was at home an hour later about to mount them on the car when the phone rang. It was the DMV telling me that a form was missing and I had to return the plates to the DMV. The registration has been in process for two months and I am hopeful of getting plates in the next week or two.

I trailered the car to a charity car show in Denver last weekend and displayed the car with the Lotus Colorado (LoCo) club which I have joined. The car got a lot of attention. At the end of the show, a 5/8 scale Louts 7 named .7 hitched a ride to its home on the back of my trailer.

The car gets its first track day on June 23rd. I will post a video of a lap or two.

The start of this project is here
Flyin Miata