Blown Aston

Ken relates: "Lynx Motorsport contacted me whilst I was freelancing at BBR and asked if I could help them to turbocharge an Aston Martin Virage that had already been increased to 7 litres but had failed to impress their wealthy client. As "No" is not part of my vocabulary, the next step was to have a look at the car. A trip to the Lynx factory at Hastings was organised for a viewing…"

Having spent an hour or so looking the car over, I was asked whether or not the operation was possible. Well just about anything is possible, so taking a leaf out of the American’s book "would it stop us going to the moon?" I answered "when do we start?"

It was going to be difficult; there were lots of things in the way and there would have to be some subtle chassis and body modifications – not to mention the power proposed to put through the transmission and the effect this may all have on the handling!

After discussing general terms, the car was brought up from Hastings and work commenced. Due to the lack of underbonnet space, the large V8 occupying most of it, there seemed to be nowhere to put anything. We found that if we could move the water radiator forward, we may be able to squeeze a blower in front of the engine. In order to do this, it was necessary to create space in front of the radiator and this was done by resiting the air-conditioning heat exchanger forward and changing the engine oil cooler and the automatic gearbox cooler - as well as some bodywork modifications behind the front bumper and valance and chassis cross-member.

The turbo options were to fit two or one. If we fitted two, it meant double the installation with regard to inlet and exhaust systems. Two blowers take up nearly double the space even though they are smaller than a single. I took the challenge to a well-known American turbo specialist – let’s face it, all their turbo applications are huge out there! We bought the biggest we could get and a variety of exhaust housings with varying A/R ratios so that we could find the optimum size during dynamometer testing.

Meanwhile, we set about looking at the intercooling. This was to be the biggest nightmare. Where shall we put it? We already had a problem squeezing the turbo between the radiator and the engine. The only space was behind the enormous front bumper, which being made from plastic, could be modified to allow for a very large intake, ducted to the intercooler. The intercooler was drawn and manufactured and was sited as low as possible behind the bumper and underneath the oil cooler & power steering cooler. The pipework then had to be made to go from the turbo to the intercooler and the intercooler to the engine’s inlet manifold, via the two throttle assemblies. These were BIG pipes; we were looking for more than 1,000 lbs.ft if torque and approaching the same in horsepower!

Another equally absorbing problem was the exhaust system. This was a modern car and the emissions had to remain no worse than the original car so that it could pass its emission test. The system also had to be made in stainless steel, which can handle the temperature increases expected of up to 1,000°C. We took the problem to Primary Design in Thame, who are more used to making Formula One exhaust systems and we designed a double manifold to run forward from the engine and join just before the turbo mounting plate. Where the two manifolds met, we had to fit a wastegate valve to control boost so there was a further mounting fitted for this. The turbo, having eventually arrived from the States, was mounted to the new manifold assembly and the exhaust exit pipe was made and fitted through the chassis towards the rear of the car. To control the emissions, we approached Johnson Matthey, the huge catalyst manufacturers and their specials division made some stainless steel substrate units, heavily loaded with Platinum and Rhodium. We collected these and made stainless steel housings prior to fitting them in front of the custom made stainless steel silencers.

Whilst this work was being carried out, a special automatic transmission was also ordered from America and modified to suit the car by an automatic transmission specialist in Birmingham. This unit was to have a computer controlled gear-change system, which could be mapped in the car to suit the car’s power characteristics.

Once all the installation problems were sorted, the engine was removed from the car and fitted to the dynamometer for tuning and power testing. The standard electronic ECU was replaced with a more sophisticated system with twin Lambda inputs and closed loop fuel & ignition system. This was carefully mapped to suit the turbo and all throttle positions. The most difficult part of mapping is to get the transients right – in other words, to get the engine to run smoothly at any speed that the throttle is opened and to "stay with" the engine’s requirements during hard acceleration and all other times.

After about 3 days testing, the engine was ready to be re-acquainted with the car; 1,250 lbs ft torque and nearly 800 bhp – pretty awesome!

The engine and all the new ancillaries were fitted together with the new transmission system. And the car returned to Lynx for suspension modifications, paintwork and road testing.

Over a year had elapsed before the car was returned to the client!

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