Train Whistlin' Ex driver
Join Date: Dec 2017
Location: Montgomery, TX
I suppose the SCT could be limiting boost to 20 or so. Do you have their street tune to try? The only time my VGT cycles between 14&84 is during it's idle sweep. It will get up to about 70 if I lay into from a stop, but typical operation seems to be about 40-65.
Did you check your MAP
port/hose from the intake?
Does your buddy have the stock turbine wheel and turbo? My 03 whistles like a jet on a strafing run, but the 13 vanes on the 04 and up's are kind of tame, also the engine rumble does eventually overtake the whistle.
2003 Excursion 6.0, 2004 front cover, Stock head bolts, unknown EGR delete, 4" Diamond Eye turbo back exhaust, Magnaflow 60110 catalytic converter (makes the '03 whistle livable), Hellwig Sway bar, Roadmaster Active Suspension, Gearhead tunes - 8k tow or SRL depending on my level of 6.0 paranoia, unknown work by previous owners...