What's the difference between the two? The hy and hx? Did they come on different years of trucks? Or is one of those things I just have to look for on the tag on the turbo?

hx came on manual trucks and hy came on automatics. 9cm housing to help spool the auto.

Thanks! I put the new elbow on and boost is higher and better now

i clamped off the wastegate line on my S300, and saw no change up or down,
And i'm topping out at around 35 pounds of boost. ~ Not enough fuel ?

i just pinched mine the other day after talking on here, and it helped a little with psi but cooled my egts down a bit, was hittin 1400 easy on low now its hard to get it to 1400.

Good thing I put that boost elbow on today, on the way home from work tonight a chipped common rail blew smoke on me after riding my ass so I set the ol edge to level 5 and smoked his ass in a race traffic light to traffic light.

Keep your drive pressures low so you do not create a restriction on the exhaust side causing unnecessary boost/restriction or blow your head gasket

As I understand it the drive pressure is the pressure that is between the exhaust manifold and the turbo. Those with wastegates closed off or running a turbo with a small non-wastegated housing can have a big restriction if they do not have a wastegate that allows the the extra air to bypass the turbine wheel reducing the pressure and helping to keep the turbo from overspeeding and creating excess boost leading to even higher drive pressure.

for instance the 71mm turbine wheel is called the LDP or low drive pressure wheel and because drive pressure is lower (and slightly more mass of the larger wheel) during normal driving the turbo does not spool as well, but at higher RPM and higher boost it allows the air to flow more freely out of the engine and manifold.

It's the ratio of drive pressure to boost that's important. You can't have one without the other. Pressure is resistance to flow.

Hell ya!:choochoo: