When we did my initial turbo setup, we just slapped everything on and filled the tank with 93 octane and the car ran fine for 20K mi. EGTs were too hot by 5500rpms though so after the first month of hard driving I just used the power for easy 5th gear highway passing and I didn't rev much past 5000rpms. Still on a totally stock ECU and fuel system I put out 146whp and 155wtq at 5psi, intercooled with a small turbo. I don't necessarily encourage this for anybody else, but it worked for me and
could work for you as well.
I decided to go this route because Aerocharger, back in the day, sold their base kit with 5psi non intercooled and said it was OK. Granted not everybody with the base AC kit got away without deto but some did. Figured if we got deto I could always add water injection and that could fix that.
My dad's also gonna go this route when he turbo's his Focus because it's the cheapest and it's worked before. If it doesn't work for him, he'll then look into fuel and ECU upgrades. One thing that might work would be to make a homemade JSRC black box. All you'd need is a pressure switch wired into the fuel injectors to ground them open when it sees boosts. That might give you a decent fuel ratio for 5psi but it would make your injectors work 100%.
Getting a base HP home made turbo setup is easy, but it is a risk. Here's some required reading for you.
Zetec Turbo FAQ
