With wheels, acceleration is affected in many ways, here are just a few:
1. The weight of the wheel & tire. Rotating weight matters MUCH more than sprung weight (weight above the springs ~ interior, A/c, etc ...)
2. The overall diameter of the combination. A smaller over all diameter accelerates faster, but you lose mph per gear.
3. Sidewall design. For "Drag style" launches, you generally would prefer more sidewall, especially if it is squishier. A low profile 17 is terrible for drag racing.
IF you happen to have a 15 and 17 combination that are the SAME overall diameter and have the SAME weight and happen to have the SAME "sidewall launch capabilities" then there should not be any performance gain/loss.
*theoretically* ... and yes, there are other factors. This is simplified.
As for the initial question:
The header SHOULD add real HP.
The rim/tire combination might hurt or help your launching.
Generally speaking, for regular street tires, you will have improved handling with the 17" with low profiles.