[cmefly]

I'm thinking of adding a Flowmaster American Thunder Cat Back and a K&N FIPK. Should I go with both or one? Would a drop in K&N be better? Live in Northeast. Thanks!

 

[Strongjeff]

go with a drop in, a ported throttle body (80MM) and yes the cat-back

 

[cmefly]

Should I go 80 or 85? Also, would I have to Tune it after adding that? Should I add a Catch Can too and if so would the stock air filter housing interfere? Curious as to why you would opt for the drop in. Thanks!

 

[Strongjeff]

based on others experiences on the hemi, the stock airbox give better low end over a cai. the 5.7 likes the 80mm over the 85mm. I would go 85 if you have major mods internally, or running boost. 80mm for a mostly stock motor with bolt ons and tune

 

[Strongjeff]

not sure on a catch can

 

[dmsfun]

the 5.7 likes the 80mm over the 85mm. I would go 85 if you have major mods internally, or running boost. 80mm for a mostly stock motor with bolt ons and tune

Not the case if you go with a taper ported 85mm, as you get the best of both worlds. Unlike a straight bore 85, no tuning is needed for A/F, and I immediatley noticed better throttle response at all RPM. The modern Muscle 85 TB was the second mod I put on after catch can.

Catch Can is the first thing to get. Not only keeps the throttle body and intake from getting caked, the Hemi runs better. WIth the stock setup, when those unburnt hydrocarbons are fed back in to the intake through the PCV, the effective octane number is reduced, and the ECU pulls timing.

 

[cmefly]

Thanks. Can the Catch Can be added with the stock air filter housing?

 

[Strongjeff]

Not the case if you go with a taper ported 85mm, as you get the best of both worlds. Unlike a straight bore 85, no tuning is needed for A/F, and I immediatley noticed better throttle response at all RPM. The modern Muscle 85 TB was the second mod I put on after catch can.

Catch Can is the first thing to get. Not only keeps the throttle body and intake from getting caked, the Hemi runs better. WIth the stock setup, when those unburnt hydrocarbons are fed back in to the intake through the PCV, the effective octane number is reduced, and the ECU pulls timing.

I had forgotten a tapered bore