I'll point you in the right direction mate, it's called the bank as you'll need a fat loan to get 300bhp out of the C1J & keep it running

If you want that sort of power get a loan for £3-4k & do the clio conversion, it is proven to take 300bhp+ easy, the C1J can be done but not to a road car IMHO.
250-260 is about manageable mate, as i'm about to ind out.
You need to get the fueling sorted, very hard at that boost (30psi+) big lag monster turbo, a cam of some sorts, prob a custom jobbie, forged pistons & prob steel liners, headwork, prob big valve head.
NOS maybe as well.....
Lightened & balanced engine, twin or tripple plate clutch...
Why do you want 300 bhp in a road car anyway, just to brag to ya mates you have a 300bhp GTT ??
If so stick a big arse turbo & NOS on it & go to the local rolling rd, it will be shit on the raod though.
It's a 1.4, 50 year old engine (the design) at the end of the day
