Hi Jazza, The performance you get depends on how much you want to spend and what you want from it. If you want it to be fast and last you need to spend more. Talking naturally aspirated, if you want it grow to bigger balls you will need to do many things to it - install extractors but you wont get full potential unless you get a bigger exhaust system all the way [up to $900 ] - Replace the stock intake air filter with a good quality high performance air filter (K&N) or for higher power go a Cold air intake system (don't go short RAM intake) [up to $300] - Use high quality sparks and leads (NGK Iridium are good) [up to $200 ] - Use high quality fluids and lubes (Penrite worth a look) [up to $300] - Use high quality fuel (i use BP ultimate) but you wont get full potential if your engine is not tuned for it - Use a ECU upgrade or replacement (avoid piggy backs and check support for AC etc. Checkout Powerchip) [ up to $1200] - Use high quality radiator hoses (thicker and stronger) and clamps and make sure its has good air exposure [ up to $200 ] - Increase the wheel size Try and get all of it done professionally Or install a disco potato blow your car up into pieces and throw in a bit of nitro while totally forgetting natural aspiration and top it off with a Ambi Pur vent machine You can do anything your want.. Have a chat with your local mechanic. Just remember your car is as strong as its weakest component and its also about how far are you willing to go - You can have the head machined and bored out But also know that if you modify it a way that the engine wasn't designed for its costly and useless because you screw up other components from pressure and compression. ;)
