While prepping a Mitsu TD04-13C to go on a 92 745T, I ran into some more turbo problems.

After having had the problems with the Garrett turbo for the Streak, I ran into some similar problems with several Mitsu 13Cs. Three in a row had turbine housings like the cracked one in the pics.

I decided to put this gallery together to show what to watch out for; and to show some of the porting work I do on the housings to improve the flow.

The Mitsu 13Cs ARE small turbos. They have their intended use, and have some good capabilities. Unfortunately, high flow and/or high boost are not what the 13Cs are about.

The turbine housing is a 6 square centimeter size housing. That is equivalent to an Aspect Ratio (A/R) of .41. THAT is small. No matter what I might do with my die grinder and carbide burrs, there is no way that I can make that housing flow as much as a .48 A/R or .63 A/R housing on a Garrett.

SO, I am not going to try to do that. What I am going to do is to try to optimize the flow in the context that I have: a .41 A/R housing.