Adjustable Boost Elbow + EZ? Worth it?

[Max Wedge]

I have an adjustable boost elbow (allen set screw in it). I am making 26-28 psi loaded now. Would it be worth experimenting with this elbow to gain more boost? I know more boost doesn't equal more power. Several months ago some guys were testing less boost vs. more boost with the EZ, was anything determined?



Max

 

[Fred Swanson]

Max,



Screw it in all the way. You probably won't see more boost. The newer EZ's don't have the adjustable boost elbow, preset ones now. Everyone justs screws them in all the way anyhow.



I have the adjustable one on mine, and kind of like it. I use it every so often while experimenting with different combinations.

 

[Archive]

Max,

I was running 37lbs. of boost and have since cut it back to 30lbs. (EZ plus Bullydog III's. ) Even with the boost cut back I'm not blowing soot when I'm spooled up and under a load. I don't see why I should spin the turbo harder and raise the EGT's and exhaust back pressure when engine is already happy. You already know I'm a simple minded guy that likes simple things.

 

[CumminsAholic]

TopFuel- I thought that a higher boost pressure lowered exhaust temps. That's assuming that you're putting in the same amount of fuel. I think I'm right aren't I? I guess if you don't need it to help control the temps then there's no point in running a lot of boost, but I need it to keep my temps down.

 

[Briar Hopper]

It's basically a question of getting so much boost you're outside the turbo's efficiency map. No need to run it up that high, it can be hard on the turbo. It's especially bad to do so on an Hx40, the shaft supposedly isn't strong enough to stand up to a lot of that.

 

[Archive]

CumminAholic, higher boost pressures WILL lower EGT's if there's unburned fuel entering the exhaust manifold. For my setup, 30lbs. of boost is plenty enough to keep the EGT's below 1200 degress unless I drive really stupid. The trade off with trying for excessive boost pressure is the resultant turbine wheel/housing RESTRICTION and pressures in the exhaust manifold. Thats where the waste-gate comes in. I don't need the extra 7lbs. of boost, so my waste gate opens @ 30lbs. of intake pressure reducing the thermal load/RPM of the turbo. Briar Hopper is right about a turbo's operational efficiency map. Notice what a hot commodity an HX-40 is with the BIG (horsepower) BOYS around here?