Slip on vs full system... how much difference is there?

[xsr_racing28c]

I currently have an HMF slip-on on my 450r , and am wondering how much of a difference it would actually make having the full system vs the slip on.. thanks~Jason

if your engine is stock still then it's not worth it. Put a cam in and then do the full system

[quad9]

i have the full system on a motor with stock cam, runs great, but i'am sure it will be better with a crf cam in it.