1) Yep...but I have the Helix TBS too, so mine whistles at 1/4 - 1/2 throttle (LOUDLY!)
2) Yep...*REAL* loud - alot like a double pumper 4bbl carb!!!
3) Agreed...the TBS adds a bit on top of that IMO
4) I can't agree more with you on this statement!
4a) I actually had the chance to keep my foot out of it during a 250 mile freeway drive, and I actually got 12.6mpg for the first time ever! - Now, not to say that I wasn't getting 12.6 before, I have no idea - because I never could keep my foot out of it!
At least it's not as bad on gas as my '74 'Vette...it's built up *alot* and runs AvGas (BLUE Aviation Fuel - 130octane) and last I checked, it was at $6.86/gallon - and when you're getting close to 4mpg when you're foot *isnt* into it, it's not very cost effective to pull out of the garage just to humiliate the little 'Stangs or Camaros anymore...
Psychlone