As soon as I arrive, Dave Walker is into the 340R's engine bay like a man possessed. Helped by the fact that the original single-piece bodywork now splits into two distinct halves (work done by Lotus during the repair of last year's accident), the section covering the whole engine bay is soon removed by undoing 11 screws. Once the cam-cover is off, the current cam timing can be determined via two digital valve-lift measurement devices and a Top Dead Centre indicator. Dave finds the current cam timing is way too retarded (i.e. the exhaust valve is open while the inlet valve has already started to lift) so fuel is being wasted, as is power in the mid-range. Fitting the vernier pulleys mean the timing can be correctly reset to the precise degree, as measured by the instruments. Dave reckons that fitting the ΂£120 adjustable pulleys is a 'must do' on the fickle K-series if maximum efficiency is to be achieved.

Once the cam timing is set, attention turns to removing the standard ECU. It's unique to the Exige and 340R and is roundly criticised for giving them their distinctly rough running characteristics. But before we can fit the new ECU a revised interface plug has to be soldered to the loom.

Now the fun can begin. The semi-naked 340R is strapped onto the rolling road, the ECU plugged into the laptop and the engine started. The standard ECU uses vacuum from the inlet manifold as its primary reference point while the Emerald unit uses throttle position. Dave explains that while vacuum is good for 'soft' engines, when you fit high-lift cams with lots of overlap, it's better to use throttle position. This is because inlet vacuum can leap about all over the place at low revs prior to the cams reaching their sweet spot higher up the rev range.

It takes a couple of hours to fully check the ECU map. The power curve is nicely ahead of the result a few weeks ago, but then there's an inexplicable fall in power beyond 7000rpm. It looks like we've got some duff fuel on board as the ignition advance has to be wound back before a final figure of 187.5bhp (+6bhp) at 7799rpm is recorded. Over 190bhp looks to be on if the tank had been filled with Optimax. Torque is up 6 to 140.9 lb ft, still at a high 6696rpm but the increase is carried through from 3400rpm to 8000rpm.

On the 'real' road it's not the extra power that impresses first but the new smoothness of pick-up. The previous hesitation below 3500rpm has disappeared completely (only a slight hunting below 1900rpm remains) and the occasional kangarooing banished to history, as is the stink of unburnt fuel that always seemed to spew from the 340R's slightly sooty exhaust pipe.

The real shock is when I check fuel consumption for the first time. I've never cracked 20mpg before, 18-19mpg being the norm, but the first fill-up reveals 29.8mpg, a ridiculous 50 per cent improvement. It's no fluke either, as the second tank is even better at 30.5mpg! Range has gone from a miserable 140 miles to 220 miles, or to put it another way there's a saving on fuel of ΂£75 for every 1000 miles travelled.