loosing boost above 3500 rpm
 

Just got back from the dyno shop for the first run with the 2300 Maggie. Ran into a odd issue the car holds 10 psi boost until around 3500 rpm then drops off to 6 psi by 6000 rpm. Running a cog drive in rear 3.8 front pulley with super damper didnt see any signs of belt slip or the bypass opening? Was going to ask Magnuson on Monday just thought I would ask here as well.

are you sure that the bypass is not opening?

Take it to a better shop

if you find the issue would like to know. having similar issue with mine. bypass valve has been replaced.

what cam? what other mods do you have?

Belt slip. Once you start making boost, the belt stretches. If the belt isn't the shortest one you can wrestle on there, the tensioner will run out of travel and lose the ability to keep the belt tight.

I'm running the supplied belt with the 3.8 pulley and overdrive cogs.

I found the smallest belt I could barly get on and its tension is super tight. Slid the adjuster pulley as close as possible to the tensioner

Could be belt slip, but a 3.8" pulley doesn't seem that small. How about calibration, have you logged throttle position? Torque management isn't closing the throttle is it? Just a thought.

No pretty sure torque management is turned off even tired it without the air cleaner it ran worse.

Well I have full boost!!! When I called magnuson and asked how to set the vacuum actuator after I removed it to install injectors they said to push it down half way. So I just pushed it down all the way and reset the set screw and now I have full boost. Thinking that the mid point might be a preset setting to keep it at its stock 6 psi boost.

Great info! Glad you got it figured out