Ok Here´s an excerpt of Blade´s from the "what does the BP stand for" thread (note: I Know I´m copying it, but hey, I´m sure Blade is sick of typing it over and over and over and over, and yes he knows way more than me on this subject.)
"The GTX is technically a Mazda BPT. It IS our motor, except it runs lower compression (8.2:1) and came with a turbo (IHI RHB5 VJ20). (Blade)
think(s) stock they run like 6-8psi of boost.
They were never available in the EGT. They actually came in the 90-94 Mazda 323 GTX. But because the outside of the motor is the same, cept for the turbo, its a drop in for the EGT.
Two other versions of the 323 were made, the GT and GTR. The GT is our EGT motor. the GTR is the GTX motor with some different internals and I think a little better flow in the head. Either way:
BPD (GT motor): 127hp
BPT (GTX): 180hp
BPT (GTR): 210HP"
There´s the differences between the BP and the BPT (GTX, GTR) motors.