Do i need exhaust?

[Zahachee]

i have a 440 ex kit with 12.5:1 compresson, do i need an exhaust system or is stock ok?

[6858-400ex]

if you want the most out of your motor mods then yes i would and many more would recomend an hmf exhaust very free flowing pipe

[wilkin250r]

If you want the most power available, then you obviously need a pipe, but it's not absolutely mandatory.

However, if you have an aftermarket camshaft, you need to realize that camshaft was designed with an aftermarket exhaust in mind, something more free-flowing. Exhaust back-pressure is a very important design consideration for a camshaft, and it won't work properly with all the restriction of the stock exhaust.