When I turn the TST on 5/5 and I'm on it I hear a fluttering like sound, I only hear it when I have the box turned up. Any idea what this is, or is it normal?

 

Turbo bark. Is it especially bad right when it shifts?

 

Guys, Mine used to do that when it was running out of fuel, at 5 5 what are your egt's? ks

 

Yea mine flutters like at just before Lockup 3rd to OD on 1/4 runs. TST(twins) 7/7 and BDDL Performance program. My EGTs jump from 1520* to 1680* quick. I have a FASS so I am pretty sure it is the Rail dropping rail pressure or not being able to atomize fuel correctly at that demand point. My turbo bark is not a flutter and pretty easy to determine the difference. Sounds kinda like a big German Shepard telling you who is the Alfa Male.