what can i do to get more horse power out of a 5.7l hemi engine?
i know i can put a cold air intake,after maket headers,exuast pipes, turbo or
supercharger, and performance chip but is there a way to make the actual
engine make more power
The only way to produce more power without adding lots of parts would be to reprogram the computer with a tuner.
here is an example: http://www.protechautosystems.com/pcm-ecm-ecu-brainbox-computers/dodge/charger/2007/5-7l-v8/
Breathing improvements will help some, use smog legal parts. A tuner can help but if you have smog checks in your state you will almost certainly fail with a custom tune.