This be true, I've actually personally seen a dyno run on an '05 Ram Hemi before and after an Air Raid spacer and the truck LOST 3 HP. Now that's within the error tolerances of a Dyno run, but it's safe to say the TB spacer would certainly show NO gains whatsoever.

I also had a magazine a couple of years ago that tested the same spacer in a truck (I'm thinkin' it was a Cheby, but not sure) that LOST just under 2 mpgs after the spacer was installed.

We had a post around here about two years ago (tech section I think) where a guy wrote Air Raid and the response from an engineer there acknowledged NO HP gains but then he said some cop-out line like "but we don't engineer it so you can see the benefits on a dyno" I was like WTF!!!!????!!!!... LOL...