The car is a 91 Spirit R/T. Stock head, cams & intake. Adjustable cam gears; cams are not degreed. Spearco FMIC. T04E 50 trim/.63 STG 3 wheel; 3" exhaust. 3bar cal & +40s.
Before, the boost controller would easily hold the boost to 10 psi, WOT any gear any time up to 6500 rpm. No spiking. Idle vacuum was 13-15 in/hg.
I installed some piping to move the air filter off the turbo inlet and relocate it under the battery. I also advanced the intake cam 6-8 degrees since the engine lacked bottom-end grunt. Idle vacuum improved to 17-19 in/hg. Engine was much more responsive all around with much more bottom end grunt and plenty of top end charge. NO other changes made.
Now the boost creeps horribly at WOT; starts out at 10 psi by 3500, then ramps up to 18-20 by 5000 rpm. I let off since I haven't had the scantool hooked up to check for detonation.
I removed some preload from the actuator rod. No change.
I took the boost controller out of the equation and ran a hose from the nipple on the compressor directly to the wastegate actuator. Zero change to the boost creep.
I removed more preload from the actuator. The rod is pulled out approx 1/16" to go onto the swingvalve. Boost is 6 psi now at 3500, still ramps up to 18 by 5500 rpm where I let off.
Checked the actuator to make sure it wasn't broken, still moves freely(within reason that spring is good and stiff). Also checked the diaphragm and it holds vacuum for 5 minutes, no leaks. The swingvalve itself moves nice and free through it's range of motion.
Somehow I misplaced the allen wrench used to adjust the cam gear, so retarding it back to where it was is the next thing on my list unless someone has any ideas. I still don't understand why/how it could affect the boost like that... Thanks!