Common

I think it was wannadiesel that told me that all a boost elbow does it create a boost leak that allows your turbo to reach increased boost levels.

Now if I'm at WOT, the boost will not hold at 35 PSI, is that because of the elbow?

Who makes a manual boost conroller for the truck so I can maintain boost?

Am I correct with my theory?

Common

Is an elbow good enough?

Jturs

not sure baout your year truck but with the 2nd gen CTD's like mine with the Hx turbo and wastegate the way the boost elbow works is that when yuo reach a certain PSI of boost your wastegate opens releaving that pressure. so with mine i have a valve before my wastegate which blocks off all the boost to the wastegate which dosnt allow the wastegate to open so it can build max boost. do a search in the forums and you should find alot of info. others feel free to chime in if i am wrong or left something out.
JTurs

Jturs

but to answer your first question no it does not create a boost leak.

Lil Dog

Well it does have a bleed orifice in it. But it down around 1/64" diameter hole IIRC, so I doubt that would be enough to cause any damage.

The idea is the allen screw pinches flow to the WG actuator calibrated for 20 ish psi boost. The bleed orifice is between the pinch point and the actuator. This is a poor boys regulator basically. So even though you have 30+ psi manifold pressure, between the bleed and the pinch valve, the actuator only sees 20 psi.

HOHN

Good post, Lil Dog.

As for boost controllers, I got a cheapie from www.boostcontrollers.com that works perfectly well.

jh

Common

So at WOT, why does my boost peak at 34 but not hold?

HOHN

I'd say you have a sticking wg actuator. The actuator resists the initial pressure spike up to 34psi, but can't sustain against that pressure.

That's just a guess, though.

Common

Makes sense... I'm not gonna get on it though to experiment, it'll cost me $20.

Lil Dog

Or the alternate situation.. Your exhaust flow is too high for the port in the wastegate passage. Your over flowing the wastegate and still spinning up the turbo past the set point.

The gauge will spike up to say 36, settle back to 34 then as you crest peak RPM the gauge will sneak up a few pounds. Sound right??

wannadiesel

Bleed type boost controllers (boost elbows) behave exactly as DB describes. Boost spikes, and then as the pressure in the line to the WG stabilizes boost falls off. This is why the ball-and-spring type boost controllers are superior. Ditch the boost elbow and buy a MBC off Ebay, just make sure it's a ball and spring type and that there is a relief after the controller so it won't hold the wastegate open.