Much of the development has been done by R.S.Williams, the famous Aston Martin specialist in Cobham, Surrey but also Aston Engineering of Derby and Goldsmith and Young. These cars represent what the DB4 line would have become if factory development of the 6 cylinder engine had been allowed to continue.
This is the extremely quick ‘Banana’ car, as driven by Gerry Marshall and run during the 1999 season by Aston Engineering of Derby.
Modifications to the cars are not dissimilar to what the factory did when making the GT although most retain the longer wheelbase of the standard car. The engines which began with 3670cc are bored out to 4.2 or 4.5 litres, twin plug GT type heads are used as well as triple Weber twin choke 48mm carburettors. Engine output varies but an RSW prepared 4.5 litre unit can produce 420 bhp at 6800 rpm. Cars compete in various classes which allow increasing levels of modifications, so one often wonders how much of the original factory built DB4 is left!
Above is an example of an RSW DB4 lightweight that has recently come onto the market. Chassis 315 was modified for racing in the late 1970’s by Richard Williams for Lord Downe and now has an extensive race history both in the UK and US, in the hands of AM celebrity drivers such as Mike Salmon and former AML shareholder, Peter Livanos. The standard DB4 series2 weighs in at 1353kg – this car is down to 1026kg – just over the 1000kg limit for cars in the AMOC group C category. The pictures above were taken at RSW in March 2004 where 315 was being prepared for sale and to the right at the AM/Bonhams sale in May 2004.