I have 99 wrx wondering about basic modifications? Already have a full 3" ss exhaust!
Try fitting a de-cat pipe,that's the most cost effective mod,next would be a front mounted intercooler,still want more?next is a programmable ecu,and if thats not enough,fit the larger VF-22 turbocharger(easy bolt straight in fit)from a Type R STi.After these alterations you should be sitting at around 330 BHP.If you wish to have higher out put still consider the 2.5 litre Block,and version 3 STi cams and buckets(these are the most radical cams fitted to a classic Impreza).With these last 2 Mods Torque and power will be substantially increased,and you should have round about 400 BHP.
The mods AliAdean writes are good mods, but I would go for a programmable ECU and a Walbro fuel pump before anything else and get that mapped for the mods you have at the current time, so you won't overboost and also avoid fuelcut. Then after that you can move on with the mods that AliAdean writes, but always have your ECU mapped for the mods you have made, just to be sure.
thanks guys! Whats the rough cost of these mods?
This is only an estimate, but I would say around £2500-3000 for the ECU, fuel pump, de-catted downpipe, intercooler and turbo, depending on which ECU you buy and who maps it. An uprated oil pump would also be worth considering so you won't suffer from oil surge. It's only a guess depeding on the choice of brands. If you are aiming for 400bhp, you can easily spend £5000-6000 on good parts, given that you'll have some on put the parts on your car for you.
I'm aiming for around the 300hp atw. D you know any recommended tuning brands as I live in Australia!
Not really sure, but try to ask some of the guys here www.wrx.com.au