slip on or header & silencer

[mach5racing4]

I am looking at an HMF exhaust for my 400ex.I was wondering is it worth buying the header and silencer instead of just the slip on? Will the header and silencer make a bigger difference than just a slip on? please let me know thanks

[boricua]

that usually depends on your motor mods....if its fairly stock, a slip on would be good, any mods that would increase the volume of air that passes through the motor, i.e: cam, bigger bore-stroke, port and polish....would benefit more with a full exhaust.

[mach5racing4]

I have an airbox & K&N filter, a jet kit and a revbox, is that enough to need a header also?

[boricua]

yeah, sounds like your right at the border...the rev box is probably what pushed you into the header scene with the increase in volume moved over stock with nominal mods..

[mach5racing4]

Should i get a header also or would i be alright with just a slip on?
my funds are kinda low right now so i am leaning towards just a slip on.please let me know, thanks alot

[mach5racing4]

ANYONE???

[cals400ex]

after going through this along with two of my buddies, we came to the conclusion it is just best to get it all the first time. my buddy went from a white brothers slip on to a hmf full system on his 406 and i think he got as much power from the pipe upgrade as he did from his cam and piston combo. it was totally a night and day difference. there is no way i would get the slip on, but that is my opinion. many people say the slip on will provide better low end power. i say BS to that. his 406 was a terd with the slip on. i just thought something was wrong with the bike. it revved slow even in 1st gear. well, it smoked stock or piped 400ex's but it was no way near my bike. after he put the pipe on, he had so much more low, mid, and top end power. the decision is yours.....