As the others have stated Flue Efficiency isn't the strong point of the H2. And it's a contradiction of theory to assume you can achieve more HP or do something to add HP and still be able to increase flue efficiency.
You could change the heads, cam, and add headers. This would increase your HP without Supercharging. It all kind of depends on what you want to achieve, and how much you're willing to pay for the results.
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rubicon33:
I have a stock 2006 H2 SUV with a replacement airtube in the intake using the stock filter. Who can tell me how to make more power without a supercharger and possible make the truck more efficient? </div></BLOCKQUOTE>