the backpressure theory is bullshit...low end loses (if there are any) have nothing to do with backpressure...take any fluid flow mechanics class and then holla at ya boy... get the right aftermarket parts and u'll be aiight...and the 12hp gain, that was at the wheels im sure, sounds like he got some weak parts....and when u dyno a car the hp gain is always gonna seem alot less than what you thought u'd be getting because when companies rate their mods they normally rate it as a gross gain (at the flywheel or crank) but when u dyno it u're measuring the net gain at the wheels after powerlosses thru the suspension, drivetrain, etc so it's gonna seem lower than you expected. And one thing you have to remember, not all mods are the same...one intake may add 10 while another only adds 3...one cat back may add 12 while another adds 4...research the parts before you get'em, make sure you get the parts with the biggest gains so you're not kicking yourself in the ass for gettin the wrong shit...and whoever said backpressure wasn't bullshit, u need to do a search for the thread where backpressure is thoroughly explained for what it is....restriction to flow IS NOT GOOD. if backpressure is so good, why not just stuff a potatoe in your exhaust? then u'll have all the backpressure u ever wanted, and according to your theory your low end torque should go thru the roof.....pure bullshit