MARCOS RACECAR

My previous Marcos was a beautiful Mantula Spyder which I had hunted high and low for a 12 months to find a really good original example. I owned the Spyder for 7 years and loved every minute of it. The 7 years were a constant development of the car to improve the drivability and handling of it without altering its exterior originality. The 3.5L V8 was already in a mild state of tune, it was fully balanced with a fast road cam, weber 500 carb, modified heads and tubular manifolds. It was a very smooth and efficient engine and allowed rapid progress when asked of it.
The car was a really good open top tourer that was also capable of some really involving and quick cross country drives.

During the first 4 years I had replaced all the shockers with AVO units, replaced all the suspension bushes, fitted anti-bump steer kits, wider track front wishbones and also fitted front and rear anti-roll bars. I kept the standard 14 inch Revolution wheels and tyre sizes because I liked the way they looked and they allowed a sporty but cormfortable ride. All the mods allowed me to set the steering and suspension up accurately and it greatly improved the way the car drove. Around this time I started to do the odd trackday, the first being at Binbrook, an old airfield not far from Cadwell Park. I had spent all this time on the car and I wanted to get aquainted with the handling when it was on and beyond the limit of adhesion of the tyres.
The car handled great! It understeered if not enough power applied, oversteered if too much applied and was very neutal in the middle. All very progressive with no nasty surprises, the car was just so very easy to drive really fast! From Binbrook I then started going to Cadwell Park where the car really went much better on the smoother surface of this fine circuit. After a couple of years of trackdaying with the car I knew I was not going to go any further without some serious modifications in the suspension, brakes and tyres department. I didn`t want to ruin the Spyder as a sporty open top grand tourer, so I made the very difficult decision to sell the car to make way for an all out racer.

It took quite some time to find a 70`s steel chassis coupe with no sunroof, generally mechanically poor, but with undamaged bodywork and was priced accordingly to use as a donor car. The things learned from the days of the Spyder was that for a track car you need a stronger chassis, uprated and fully adjustable suspension, powerful brakes, sticky tyres, less weight and more power. Work started on the car early in 2003 with the building of a brand new chassis incorporating quite a few modifications to the standard Marcos item.

The new chassis is strengthened by triangulation and stressed alloy panelling to increase the torsional rigidity. It has wider based and wider track tubular wishbones along with strengthened brackets fitted to the chassis. Mountings have been fitted to accept the front and rear anti-roll bars and also the larger radiator.
The engine bay has been modified to accept the Rover V8 and 5 speed gearbox, which have replaced the original Ford V6 and gearbox. It sits further back in the chassis and the centre rails have been modified to allow the removal of the gearbox without removal of the engine, as you have to do in the Mantula. The Capri 3L axle has been retained and the rear suspension kept as standard apart from strengthened shocker and panhard rod mountings and relocating the rear leading arm mounting points on the chassis. All suspension bushes have been replaced with Polyrace items along with new Gaz fully theaded body shockers and uprated coil springs. Adjustable anti-roll bars fitted front and rear.

The brakes have had a major upgrade to HiSpec Motorsport 300 x 28mm vented and grooved racing rotors on alloy bells with 4 piston alloy racing calipers on the front. The original rear drums have been replaced with 249 x 10mm solid discs with Ford fully floating calipers incorporating the handbrake mechanism. A Willwood alloy pedal assembly with tandem master cylinders and adjustable brake bias bar controls front and rear braking effort. Aeroquip brake and clutch hoses are fitted throughout the car. Wheels have been upgraded to Compomotive motorsport 7 x 15 rims up front and 8 x 15 rims to the rear. Tyres vary depending on track conditions, but generally 205/50-15 front and 225/50-15 rear are used most of the time.
To improve the performance over that of the original car, one of the easiest things to do is to reduce the weight. A steel chassis V6 coupe normally weighs over a 1000kgs, the Rover engined Mantula nearly 900kgs. The trackcar currently weighs 790kgs with further weight reduction planned over the winter months. Well over half of the weight reduction is achieved by removing the Ford V6 engine and gearbox which is all cast iron. The Rover V8 engine block and heads are alloy and so is the gearbox bellhousing and 5th gear housing, therefore much lighter. By removing all the interior trim, dash, heater, Marcos pedal carriage assy, electric windows and glass, steel fuel tank, cast iron front hubs and calipers, all uneccessary bolts, brackets,fittings etc another 100kgs came off the car.
The engine and gearbox are approximately 3 inches further rearward in the chassis than they would be in a Mantula or LM. Weight distribution is further improved by fitting a new alloy fuel tank at low level behind the rear axle on the boot floor. The battery in now located in front of the rear axle behind the passenger seat area. A greater percentage of the remaining weight is now on the rear wheels to improve traction and braking.

NCM 109H made its track debut in Feb 2005 and has had a very busy year so far, as always, there is still much to do on the car. The basics are there and are working well, the car has been very reliable with no major problems as yet! First impressions, very pleased with things so far, much quicker on the track than I imagined it would be at this stage of the cars development. It is going to be another lengthy process of improvements, but the car has got huge potential, there is a lot more to come!

Address and Business Hours