Originally Posted by sfearl1

i believe my car had a noticeable improvement in throttle response after adding the drop in filters.

Originally Posted by PaulZ370

Try this at home with your vacuum cleaner:

Turn it on, then use the attachments on the hose. You will notice that the more restrictive the attachment, the more "whine" the motor makes as it strains to pull the air through the attachment's opening. The more the motor strains, the more HP is being used to Pull the air into the attachment. In the case of a car, this means there is less HP to drive your wheels.

Same principle applies on the intakes and exhausts of cars as I've noted above.

Give the engine a larger "attachment", and it doesn't have to work as hard on "sucking" the air into the chambers. Free-er air flow = less work the engine has to do just to breathe, the more HP is now left over for the drivetrain.

Why do I know this? I am an engineer - and as such, I have dealt with calculating useable HP for Generator Engines considering pressure drops due to intake and exhaust piping. Piping (both intake and exhaust) have a tremendous effect on useable HP from the engine. This was a major factor in my choosing the FI exhaust system by the way - it has the least bends with the least angles (no 90's) which I know for a fact translates to less back pressure and more useable HP at the engine as a result. Intakes work the same way. The less bends and less pipes, the easier the engine breathes, the more useable HP is available for the drivetrain...

This is not hearsay, nor conjecture, nor abstract theory. This is something I have done as a matter of practical engineering - I make my living this way by the way, with 22 years experience in the industry, if that means anything to anyone out there...