It's also a very clever conversion, because it combines the simplicity of a turbo with the instant and more linear response of a supercharger.

It's the first UK application of the new Geotec supercharger, which cunningly uses the impeller side of a conventional turbo, but powered by a compact, belt- driven epicyclic drive off the crankshaft, rather than using the exhaust gases as in a regular turbo. This means underbonnet temperatures remain close to standard and, because boost is engine-speed-related, power delivery suits the delicate balance of the Elise by giving instant, easily metered horsepower to the rear wheels, rather than the uncontrollable gobs of torque that are so often a consequence of turbocharging.

The conversion requires the engine to be removed and stripped - Turbo Technics fits its own pistons and con-rods, which are stronger, lighter, and machined to give a lower compression ratio of 8:1. The exhausts ports are tidied up and a new induction manifold is fitted, incorporating a charge cooler. This is linked to an independent cooling circuit powered by a separate electric pump, with a front-mounted radiator sandwiched to the main engine radiator in the nose of the car. Four new injectors are fitted, as is a completely new ECU to control ignition and fuelling.

It's an incredibly neat looking conversion; in fact you'd never guess it wasn't original equipment. Turbo Technics first offered the kit in 1999 after two years of on-road development and around 40 have been sold to Elise and MGF owners, but this car is the first to have the mark two version, which promises less noise intrusion to the cabin thanks to a revised drive coupling, and better overall performance, courtesy of the new ECU.

Start the car from cold and it sounds virtually standard: there's a barely discernable 'chatter' from the supercharger drive that all but disappears when the engine's warm. Otherwise only a slightly stiffer throttle pedal hints at the mayhem about to be unleashed.

In the standard car, power peaks at 118bhp at a lowly 5500rpm. I've always thought that Lotus's baby roadster works best with a peakier power curve, as with the Elise 135. Now, in the TT190, there's 180bhp at 5500rpm ί¿½ that's slightly more than 50 per cent up on standard - and peak power of 190bhp is still 1000rpm away, with another 800rpm to go before the rev-limiter cuts in. This conversion simply transforms your enjoyment of the car and moves the performance onto another plane.

The thing is, it's so well-suited to the Elise. Fitting the kit adds a mere 10kg to the overall weight of the car, while the handling is exactly as before - except that there's now enough power to really test the chassis, as grip is easily overcome should you get clumsy with the throttle. There is a very slight lag in power delivery, which you soon learn to drive around, but the supercharger remains inaudible under acceleration - only on the over-run can you hear the chatter of gears, but even then you'd be hard-pushed to distinguish it from the general rumblings in the engine bay.

The cost of the 190TT kit is ΂£6756 including VAT and fitting. You also get a free 12-month warranty on nearly new cars (΂£390 extra on older cars). And if all that isn't enough for you, then Turbo Technics offers the TT230 (΂£8924), which combines all of this with wilder cams and fully ported heads to give 230bhp at a higher 7000rpm.

It doesn't stop there either. For the VHPD engine in the Exige or 340R, Turbo Technics has a kit with a different inlet manifold with eight injectors that lifts power to in excess of 260bhp. That's over 400bhp per ton in a 340R...

The great thing about tweaking Elises is that they're so light the gains to be had are enormous, and rarely does your money produce such a transformation in performance as can be had from this supercharger kit. If you're tempted by the TT190 I don't think you'll be disappointed.