Ginetta G27 Kit Car

A Two seater roadster powered by Mazda RX7 12A rotary engine.

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I had long thought about building a kit-car before deciding on the Ginetta G27.

A more productionised kit might have been a better choice for a first project but I was guided by my heart rather than my head on this one.

Having previously owned a Mk 1 Mazda RX7, I wanted to fit the Ginetta with a rotary engine. The 12A is Mazda's normally aspirated 2.2 litre wankel rotary. As the picture shows, it is small for its rated capacity, giving excellent power to weight ratio. Ideal for a very light car. The rated capacity is higher than the physical chamber size as the rotary provides more power strokes per revolution than a conventional piston engine. Other than rotating combustion chambers, and having no cam shafts, cam belts, moving valves etc. it operates in a very similar way to conventional engines.

The car was 'completed' in 2000 when it was subjected to the SVA test (Single Vehicle Approval). This is like a super MOT or non destructive type approval for kit cars, small production runs and import vehicles. It checks everything from weld quality to noise levels and documentation for fuel pipe conformity. Quite a task but very re-assuring once completed.

There is still a lot to do on the car but it’s complete enough to drive on the roads. A Roll bar and some weather protection are high on the wish list. Some carpet, a good stereo and more pedal box room would be quite handy. It’s not really a practical every-day car yet but for a bit of fun it's ideal.

Access to the engine is good with the bonnet hinging forward, although there isn't much height even for a small engine..

A custom exhaust was required, for which a model was made from aluminium heater hose and glass fibre. A local tube bender then copied the model in 2.25" steel tube.

The air filter is also custom made to reduce the height required.

The wiring is a little different from the norm. I decided that I didn't want thick bundles of cable running all over the car so I designed a micro-controller based single wire communications loom. Basically a fat power and ground run around the car with a small signal wire for communications. At suitable places around the car I put receiver modules driving up to 8 local loads. Receiver modules use Power MOSFETS and a PIC micro. The transmitter again uses a PIC micro sitting behind the dash with the various stalk switches and dash switches plugged into it. For the next upgrade, I plan to add functions to read back from modules to allow temperatures and pressures to be monitored by the micro. Also PWM or Pulse Width Modulation on the power outputs to allow soft start and variable speeds for fans and other motors.

An early trial fit of the engine and gearbox to test gear lever position for comfort before getting the prop shaft shortened and balanced

Front hubs are from a Triumph GT6 with Spax adjustable coil over dampers and Ginetta wishbones. At the rear is a live axle with Ginetta trailing arms.


	A pair of Toyota Supra headlamp motors have been used to power the popups. A future job to improve styling is to replace the lamps with small projector beam units and reduce the travel on the popups to give a less startled look!

Seats were a difficult choice. I would have preferred to buy off the shelf but in the end I had to go custom. There really is very little room for a large seat and a 6ft driver. Essentially, the seats are just trimmed panels to line the body tub. This gives maximum room but no adjustment. I find it very comfortable though and the body tub makes an excellent bucket seat. The 3-point harness holds you firmly in place.

A little help from Dad is always welcome!