Hand porting a turbine housing

[Jay Whitely]

Hey guys,

I have a Garrett T3 4-bolt turbine housing.  It does
not have the 4 cast bumps in the corners like the
older style 5-bolt housing. Does this type of housing
still need to be ported? If so, how deep should I go
with the porting?

I did notice that the 4-bolt housing has a slightly
smaller inlet than the 5-bolt housing.  When looking
at the turbine inlet, the longer part of the rectangle
is 61mm on the 5-bolt housing and only 58mm across on
the 4-bolt housing.  I was thinking of enlarging the
inlet of the 4-bolt housing to match the exact size of
the gasket I will be using, which measures 61mm
across.

Any thoughts here?

=====
Jay Whitely
Tampa, FL
1996 200SX SE-R
GTi-R powered, F-MAX Stage 2