Friend just bought a 09 5.7 hemi Challenger. After a month of hard driving he want to go cobra hunting. I told him that is one snake his 5.7 should stay away from but he want to fight the fight. The car is a stock 5.7 with a stick. He do not want to touch the bottom end. He has already added a K&N inlet air box. What is the best bang for the buck without going the supercharger route? If supercharger is in the future, what is the best system?

He could have bought a nice used Viper and blown just about anything off the road.

That water-buffalo will have it's hands full trying to keep up with a new 5.0 let alone a Cobra.

Boost or Nitrous is the only way he's going to even think of keeping up with a Cobra.

Cobra=600whp and about 3700lbs.

with that said: He will have to go into the Bottom end. The Pistons just won't hold up to anything beyond N/A. Ring-lands are really thin.

DiabloSport computer tuner.

Even a head and cam will only net about 420-440 wheel in a 5.7 Eagle motor.

He needs a KB to really keep up. Sad but true. The Challenger has about 800 more lbs than a cobra.

Supercharger is the way to go. Magnuson is great. I have one and they're 50 state emissions legal. Adds about 120hp. As far as bolt ons go, cat back exhaust, high flow cats from Magnaflow (if you're not in CA). Suspension helps handle and hook up better, so Hotchkis is pretty good. Tires are a big weak link with these cars. Those Goodyears flat out suck. Also, he could get a Predator tuner and that'll give him more hp and better throttle response, but if he gets a supercharger it'll come with a predator.

Thanks to all. Good information.