The second is learning how to drive properlyThe cheapest performance "upgrade" is making sure everything is working 100% as the factory intended.
Chris we have been through this, please buy one slap it on and you will see it works perfectly fine boosts you 2 + psi and gives you lower rpm power il put my keys on it. the A/F is not affected at all.
cant believe someone hasnt said this already.....seriously "cheap" and "performance" really don't even belong in the same sentence."cheap performance", Just remember 1 thing, Cheap parts aren't good, and good parts aren't cheap.......Nuff said
change fuel filter, (these can clog up causing a lack of fuel pressure to the regulator, meaning lacking performance) only £10, if that, from halfords.
replace air filter, (if not a performance replacemet) then just a standard filter will cleen up the air intake, and make ur car breath easier.
make sure you have the correct apark plugs, take them out give them a cleen up with a wire brush, - regap them - replace
oil change - will make your insides runs smoother, and quieten down the engine.
cut a hole in your wastgate line, that goes to your apc, about a 5mm hole, will add about 2psi of boost.