HMMM...where do I start.
First, what are you dropping a turbo into?
If the kit doesn't include these things you need to do the following:
Upgrade the fuel system. You may need bigger injectors, higher flowing fuel pump, adjustable regulator etc...
If it's a computer controlled car you may want to look into custom tune.
Hopefully your engine internals will be able to handle boost. Cars that didn't come turbocharged somtimes don't have strong enough parts for boost. Things like forged pistons and hardened valves are best for turbo applications. If your engine doesn't have these componets and others you may survive for a little while but when you start cranking up the boost, don't be surprised if you end up with a set of piston ashtrays.
A blow off valve will extend the life of the turbo and prevent compressor surge.
You will want to install a boost controller of some sort.
If the car has a MAF sensor you might need to upgrade that as well.
Kevin
