Xsi engine upgrades (need advice)

[Niall]

Modifying petrol engines is generally more expensive than dervs when it comes to 306s but its all about what you want. The other thing you need to remember is the further you push a engine, the more its likely to break down. Thankfully Peugeot engines are pretty damn bullet proof (with exception of the TUs used in the 306) but still doesn't stop failures. Big boost DT engines often see rods spat out the block or HG issues.
Firstly you need to choose a fuel. There is benefits to both and if you go for diesel, you are in the right place for advice here. Even if you decide on petrol there is a fair few people here to give sound advice. Then you need to decide how you're going to get more power. If its derv, its 99% going to be a turbo. If perv, you could go turbo, throttle bodies, roots supercharger, centrifugal supercharger or even just highly strung single TB. All have their pros and cons