Whats the difference between hollowed out stock cats and hi flo aftermarket cats??
ttt
i’ve never hollowed out a cat… but that’s basically taking your stock cat and “hollowing it out” … which basically makes it like a straight pipe.
a high flow cat… is still a cat converter, but is larger diameter to allow more flow. these are CARB legal. the previous is definitely illegal.
Im sorry …what I meant was what is the performance difference between the two?
Originally posted by 11seconds
Im sorry …what I meant was what is the performance difference between the two?
either way, don’t expect too much. maybe a few extra horses. but expect that it’ll change the sound of your exhaust (most likely make it sound more raspy 
)
please help save your Environment by not gutting your cat. It sounds like poop when its done anyways. If you want a high flow cat just buy one. there is a reason why they are on in the first place.
To answer your question in a NA setup i would think the amount of HP your creating there is no need to ad a high flow. Its really not going to help all that much. In a Tubo or SC application this would help greatly.
point blank buy the high flow if your going to gut the OEM. please. 
Originally posted by MansonClubPuir
[B]please help save your Environment by not gutting your cat. It sounds like poop when its done anyways. If you want a high flow cat just buy one. there is a reason why they are on in the first place.
point blank buy the high flow if your going to gut the OEM. please. [/B]