Engine/Transmission (1994 - 1998) Star Wheel question

[tschwab]

Could someone refresh my memory about the AFC Star Wheel.

Turning it towards the engine (clockwise) = more smoke, power and quicker acceleration?



Does the star wheel have anything to do with boost? I love the power my truck makes but the boost seems pretty high, I can hit almost 40 @ WOT.



See signature for mods. My dads truck is BOMBed exactley the same, but his boost never goes as high as mine. I'm thinking it may be the star wheel, I have played around with mine, he has not.



Thanks - Terry

 

[Ben Rumson]

As you're standing on the side of truck looking over the driver's front tire into the engine compartment, turing the wheel from bottom to top (towards the engine) loosens the AFC spring, rotates the star wheel forward, and adds low-end fuel. Turning the wheel from top to bottom (away from the engine) tightens the spring and reduces low-end fuel.



Set one of your wheels to the same location as the other vehicle and then check things again.



This adjustment is primarily done to tweak low-end smoke. Although it would have some effect on boost, I don't think the wheel adjustment is the answer to your boost differences.



Is there an expert in the house?

 

[JGK]

Your star wheel does not affect boost, it is affect BY boost. It is attached to a lever or "finger" that reaches down by the torque plate and holds the rocker arm back until boost builds. Once the boost comes on, the lever moves back out of the way and the torque plate comes into play regarding fuel control. Backing off the tension on the spring by rotating your star wheel toward the engine allows the AFC lever to move out of the way sooner (at lower boost) and thus adds more fueling at low revs and therefore a little more power. However, since this adds more fuel before the boost comes on there is more smoke.



I think...



-Jay