Not that the standard 5 litre V8 Griffith is lacking in the performance department but my philosophy is that you can never have too much of a good thing! As part of the first year service the camshaft was replaced with a 335 cam supplied by TVR Power and fitted along with solid-lifters and adjustable steel pushrods by my dealer, Portfield Sports & Classics. Around this time Tim Lamont was developing his ACT Performance Products carbon fibre upgrades business and asked me to be a guinea-pig for his carbon fibre twin-throttle induction system - comprising plenum chamber, air-box, alloy flared trumpet base, upgraded airflow meter and a Jenvey twin-throttle body. During a session at Power Engineering Tim fitted the induction system following which Mark Adams fitted his Tornado chip and mapped it to the engine. The result of this was an addition 16 bhp and 10 lbs/ft torque overall but more importantly max power was now produced at 5,900 rev's up from 5,380 previously, with torque remaining solid at 250 lbs/ft approaching 6,000 revs whereas before it fell away rapidly after 5,250 revs.

A year or so later Tim was in touch again to let me know he has a pair of stainless steel header manifolds ‘going spare’. These have no pre-cats and are fitted with reversing cones designed to minimise back pressure from the exhaust gasses as they reach the main catalyst. With these fitted by Racing Green it was time for another rolling road session to, as Mark Adams put it, ‘fettle’ the chip to maximise the benefits of the new manifolds. Mark now works at Austec and along with Paul Austin they managed to get substantially more power from the engine. During the session Paul fitted Bosch fuel injectors which provide an improved spray pattern and flow than the Lucas items, Magnacor ignition leads and a new Bosch coil. With this done the maximum power achieved was an excellent 325 bhp however the best balance of power, torque and drivability was found to be with a mapping that produced 300 bhp and 325 lbs/ft of torque. It would be nice to boast a 325 bhp - 325 lbs/ft engine and I have the print-outs but in the real world it’s on the road that matters!

Thanks to:

ACT http://www.actproducts.co.uk/

Austec & Mark Adams  http://www.austec.co.uk/

Racing Green http://www.racinggreentvr.com/