Need tips and tricks on modifying turbo's.

[Guest JAMIE T]

I'm building a T3/T4 turbo. I am using the stock exhaust housing and wastegate. I have read about porting the wastegate hole and using a larger puck. Can someone describe that process? How big? etc...

 

I have a few more questions, but I need to go out for beer, later.

[yo2001]

I got 1 inch hole with a 1.25 inch puck. I've heard you can go bigger if you go with GN WG puck.

[Guest JAMIE T]

OK, here's another question. Stock turbo has two vacuum lines that come off the compressor, they both go to the waste gate. My new compressor housing doesn't have any vacuum ports coming off it, what do I do about that?

 

1" hole, 1.25" puck huh? Was the hole opened up with a die grinder or bored out on a mill? Is the seal crucial?

[yo2001]

I'm pretty sure mine was milled. But I've heard die grinder. The vacuum port(s) all depends on what you what. If you want best boost response, you can have no port on the compressor housing and get boost signal from the intake. If you want to be safe with over boosting, you can drill and tap a NPT and put a fitting on it.

[Guest 81na ZX]

In the DSM world, on Mitsu turbos, a new-ish mod is using a 34mm wastegate flapper. You port out the stock hole to 28-30mm (die grinder), and fit the 34mm flapper in - these turbos usually either use a cotter pin or bolt to hold in the flapper to the WG arm.