P20?P18?MD321?
 

Whats does things like this mean?

And where can i find out more?

The MD321 is a specific type of turbo, based on using a Garrett GT series ball bearing core.

P18, & P20 refer to the two sizes of Subaru IHI exhaust housings.

In context, the MD321 uses a modified version of the smaller P18 exhaust housing, which gives better spool up, & response than the larger P20 exhaust housing.


Mark.