Spiky - If an engine is 1500 to start with I am damn sure by the time you have fabricated it in to your Peugeot you will be over the cost of slapping a Turbo or SC on your GTi-6. And if you have one off parts like driveshafts and mounts then things get messy if you start breaking parts at the track.

If 3k is to Rotrex charge your GTi-6 you can get an easy 300bhp out of it if not more and would be perfect on track as the Rotrex keeps a linear power delivery so it just feels like a bigger capacity engine. That would be my choice.