Tim Lamont from Act Performance Products has kindly agreed to provide articles for the TVR Wedge Pages on V8 tuning. This being the first in an occasional series and covers Induction mods. He has also kindly offered to answer any questions regarding V8 engine tuning.

Please note however that his time is limited and therefore his replies may be brief. Also, due to the quantity of mail received he may not be able to answer queries straight away.

Tuning the Rover V8

Article by: Tim Lamont

My main line of work is Manufacturing components for motorsport (Act Performance Products), as many of you will know I also modify Rover V8 induction, this being the Inlet manifold, trumpet base and Plenum, these are normally the limiting performance factor, especially as a large number have modified engines running standard induction. With the exception of the 5 litre for this variant TVR Power enlarge the manifold ports and replace the trumpets with larger bore steel tubes, offering better "breathing" over standard but there is still scope for improvement.

For the purpose of this article we shall concentrate on the Wedge, bearing in mind that the induction can be a limiting factor, it is interesting that none of cars including the SEAC's had ported manifold and trumpets as standard, and yet such modifications can produce a good power increase. The 390/420 SE and SEAC models lend themselves well to tuning as they have "tough" bottom ends, i.e cosworth pistons and forged conrods capable of revving safely to over 6500 rpm. As well as gas-flowed heads.

Induction modification is the simplest and most cost effective way to tune / increase power on these engines, provided the engine requires more air in the first place, for example a ported manifold and trumpet base on a 350i will produce very little improvement, where as the same modifications to a 450 will produce plenty of extra torque. On the later models fitted with Hotwire injection, ECU chipping is also beneficial as the standard "factory" chips run very lean in the mid range, which can effect the engines life span as well as reduce performance. There is however a limiting factor with the Wedge, that being the Exhaust manifolds, the primary pipes (from the heads) are too small for High output engines, i.e 300+ BHP.

	Act Products carbon fibre plenum on a SEAC

I have had first hand experience with this, when a heavily modified 5.0L, 320 BHP engine from a Griffith was fitted into a Wedge it produced 299 this was measured on the same Rolling road. Still a respectable output though. The problem is lack of space between engine and chassis to allow for proper sized pipes. However with the engines available as standard including the 450 or engines up to say 300 bhp they are adequate.

I am happy to answer any questions regarding engine tuning, although I am "in the Business" you don't have to purchase or be a regular customer to get an answer, so feel free to email me.

timlamont@actproducts.co.uk

Thanks to Tim Lamont for submitting this article.