It's under the turbo quite a bit. You really have to 'drive' the truck. Play with the throttle to get the rpm's up before you really want to step on it. First startup it smokes a lot and has no throttle response for a few minutes. Switch to my gearhead tow tune and it starts and runs flawlessly. Just not the power level I want.Just out of curiosity what does "My tsd spd has been in need of replacement." mean? I have heard very little bad things about those tunes and absolutely loved it in my truck. Just curious if you were wanting to try something different or having some sort of issue.