What is needed to use a 4"/3" turbo?

[89mulletbird]

I have a TA-49 on my car right now, I'm guessing it is 3" inlet and 2.5" outlet diameter. What do I need to get to use a turbo with 4" inlet and 3" outlet?

 

[RatFink]

You need transition hoses. My MAS intake is 3", so It's a 3" to 4" transition into turbo.
I have the dutt neck on my intercooler so I didn't need a transition hose, but they make all kinds of sizes if you have stock intercooler. Google hose techniques...I think that's the name. Pic below of what I'm talkin about

 

[John N]

Is an angled IAC mount needed?

 

[RatFink]

Is an angled IAC mount needed?

If you use a 4" MAS intake, then you need an angle boss for the IAC to fit.
it will work with a 3" inlet MAS pipe.

 

[BlackMetal]

A few guys have bent the IAC wires out of the way and haven't needed an angle adapter, but it's probably safer to spend $60 and not have to bend the wires at a 90degree angle to get them out of the way.

You can either keep your current intake and intercooler and just use silicone transition hoses, or get an actual 4" intake pipe and an intercooler with a 3" inlet and actually make use of the inlet/outlet size of the turbo.