what is the differance ? whitch one is bigger?

 

ht3b is used as the large turbo on some twins setup while people normally use the hx55 as a big single.

 

so the bhtb3 it larger than the hx55?

 

Yeah, much larger. While you could run a 55 as a single and push it to 50/55 lbs if you have the fuel, you probably could not get more than about 30 to 35 lbs of boost out of a BHT3B no matter what. Our engines just can't push it hard enough to make more boost than that. It is a huge turbo.