APEX Automotive Engineering

You've heard of a Lotus 7. A small British car with motorcycle fenders. It was made famous in the British TV series "The Prisoner".

The Champion Motor Car Co. makes pieces to build a Lotus 7 with Miata mechanicals. That is what I plan on building.

A Locost 7 frame, heim joint suspension, fiberglass fenders, hood, nose, aluminum body panels, gas tank etc., a '99 Miata engine balanced and blue printed, port and polished head, TECII electronics, aluninum flywheel, Miata transmission and independent rear end with RX7 differential. This car will not be for the street but for autocross and track use only. Driving such a small car on the track, I'll be installing a full roll cage for safety reasons. Some of the weight I'll gain from the cage will be offset by not having to deal with things like lights (there will be a brake light), wipers, windshield, heater etc. I'm still expecting 1200 - 1300 pounds wet. The power to weight ratio should be very favorable. I've been accumulating parts as I wait for the frame to arrive. Front and rear brakes, spindles, uprights, a brake line kit from Longacres along with starter and power switches. Miata steering column and steering rack.

So, that's the plan, as always, things may change as the project forges forward. I've been waiting for the parts from Champion for three months. There have been many excuses as to the delay (one being Grass Roots Motorsports magazine doing a car build and article at their shop). I think the reality is they are overwhelmed with orders . This is going to be a very popular kit. If you decide to make one, be prepared to wait for the parts (I ordered the kit 10/28/03). While waiting, order the book "Build your own sports car for as little as 250 pounds and race it" by Ron Champion (Haynes). It has all the plans and details for the car, .

While I wait for the frame, I'm keeping busy cleaning and painting parts. Many of the small parts will be powder coated with a do-it-yourself system from Eastwood. All you need is a used oven and a low powered air compressor. I have had great success using this system; many parts for Spyder were done this way.

Update: 3/27/04 The frame has arived, Almost 5 months to the day of ordering. I have the frame, fiberglass parts and aluminum panels.

I'm still waiting for shocks, springs, suspension and gas tank.

Update 4/28/04 Six months after ordering my parts from CMC I finaly have them all. I've decided to cancel the gas tank, I found out it was an off the shelf part and not the custom aluminum tank I thought it was going to be.

I've scheduled for a full roll cage to be installed, untill that happens, I'm just doing mock ups and figuring a few issues out with the frame and body.

I've decided to use the stock PPF that came on the Miata. Trying to get it to fit within the confines of an already small passenger compartment will be a challenge, but I think it can be done

I also wanted to move the rear differential more inline with the rear suspension. I wanted it further back in the chassis and higher up.

This will faciltate in lining up the diff with the trans when useing the PPF. I fabricated a new mount that should do the trick, but it looks like I'll only have room for a 5 gallon fuel cell.

The next problem I need to tackle is the bodywork. Apart from the fact that the aluminum panels I received from CMC do not fit the chassis as good as I had hoped, The fiberglass hood will not clear the engine with a '99 intake manifold.

Even without the manifold, the hood rests on the oil cap. Any kind of engine movement and the hood will be rubbing.

It looks like the easy way out of this problem for now, is to raise the nose, hood and scuttle up 1.5 inches. I'm looking into some aluminum channel to use between the frame and the fiberglass. Possibly making new side panels that will cover it.

Another concern I have is the engines oil pan, it sits two inches lower than the lowest part of the chassis.

I will be useing a dry sump on this engine so I can cut down the depth of the oil pan, but it will only gain me about an inch because the transmission bellhousing is the next lowest part. Looks like a skid plate will have to be fabricated

Update 5/22/04 I've done a few things to the car. I have shortened the steering rack and figured out it's location, along with fabrication of longer tie rod ends.
I've decided to use the Miata inner and outer tie rod ends.

It took a little moving around of the rack to eliminate bump steer, but I'm happy with the results.
CMC had made a mount for the rack, but it didn't work at all for me, so, I removed it and made my own mounts.

The PPF is now cut and welded together, it fits nicely. Now that is done, I can nail down the rear diff and the engine and get the drive shaft shortened.

The other thing I've been brainstorming is the brake and clutch master cylinders.
I want to use the Miata parts along with the pedals.
I think I've figured out a way to put the pedals wherever I want, use the stock master cylinders and not worry about the steering shaft getting in the way.
I'll get some pictures up after I get this mocked up.

Update 6/18/04 Not much has been done on the car the last couple of weeks, the chassis has been out to Chris Howard, the cage fabricator. We talked at length about what I wanted. This car will see duty on the track, so consideration for side protection as well as roll over protection was high on the list. We could have gone crazy with more bars (and more weight). Looks also played a big role in the finished product, Chris did a masterful job on the design and fabrication.

The cage added 60lbs to the car, but in my opinion, weight well spent.

Update 8/6/04 I've been very busy in the shop, unfortunately, not on Stynger. I've been rethinking the steering and have decided to can the stock tie rod end idea. The rack would have been low enough to bind the tie rods on the lower A arms at full droop. I should have gone with Keith Tanner's idea from the start, using heim joints. I also modified the front spindles to accommodate the heim joints and have a better angle at their connecting point.

The fuel tank has been an issue since I modified the rear differential location (it took up some of the room used by the fuel tank). I wanted to install a fuel cell with a rubber bladder. It is so close to the back of the car with zero crush zone, I felt a fuel cell could only help if I ever back the car into a wall. It took some searching, but I finally found a cell over 5 gallons that I could fit. It's a Fuel Safe brand 8-gallon cell, number SM108-A. I'll get some pictures of the install once it's completed.

Update 8/30/04 Some pictures of the rough in for the tank. To get the tank in the frame, the rear brace for the bodywork had to be removed. Mounts were added to the brace and nut inserts attached to the frame. The brace can now be removed and attached when needed. Straps for the tank have yet to be fabricated.

Update 11/17/04 It's been a while since the last update, but things have been progressing. I have installed the steering shaft to the steering rack.

I have the headers almost completed.

The pedals and master cylinders are fabricated,

and the radiator and fan are installed

Pictures of the removeable scuttle.

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