I finally replaced the factory turbulence generator intake hose with hard smooth tubing. It made an immediate difference on the top end. I use to hit a point at high rpm where 2/3 throttle and full didn't make it go faster, but that limitation is gone now. Getting on the freeway I punched it in 4th, and it was still pulling strong at 80! The temps seem to be lower at full throttle too. It's worth doing for sure.
I will probably have to do some insulation though, the stage IV whistles like a banshee now!

 

I did mine over the winter and even my PDR HX35 whistles quite nicely. I will be on the dyno in May so I will let you know what effect it has on the old girl.

Bob

 

I like the whistle, but it drives some people crazy. It's almost soothing to me now!
Be curious to see what your dyno numbers show.
Mark