Super chargers  
A supercharger pushes more air through an air filter system into the engine than a simple filter can do, this aids in produces amazing results of increase performance and acceleration.
Enlarge picture The bhp increase (for a 106GTi) can result in 150bhp for a stage 1 all the way up to in excess of 230bhp for stage 5, from producing a smoother increase in power delivery, which won't strain the car and suffer from lack of traction. There are only a couple of GTiís in the UK fitted with this modification, but quite a lot have been fitted to Saxo's and have proved very successful. Despite being excellent bhp/£££, they arenít cheap.
The kit cost in the region of £2500 for a fitted stage 1, upwards of £5000 for a fitted stage 5 with intercoolers and all the rest. The best company to contact would be GMC Motorsport as they have first hand experience with this sort of tuning. You ask to see the demo Saxo, wow!

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106 1.6 8v Rallye with SC
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106 1.6 16v GTi with SC

Article written by Ian Dews. 'Courtesy of Ian from'