Throttle Body Spacers- Yes or No

Throttle body spacers have been used going back to the days of carburetors. I use one on my '06 GTO. The main idea behind them is to increase plenum volume, that's all. They aren't magical devices that increase horsepower everywhere, despite what you think you feel. The increase in plenum volume provides improved breathing for the engine at high RPM. This does not necessarily increase horsepower, but it does help to move the power peak a little higher in the rev range, maybe 200-300 RPM max. However, it should also be noted that any improvements a throttle body spacer can provide will be minimal if the engine can't get more air out (i.e freer flowing exhaust)