Originally Posted by BarelyAWake
Anything that effects performance effects fuel mileage - but you may not notice that benefit as ya will prolly get on it more due to the power increase lol The Spooky one hasn't got any length of headpipe at all & the optimum headpipe length for an expansion chamber & powerband is about 12 inches (altering headpipe length allows some ability to "tune") - as you're considering extending it to a full length system, ya may wish to weld it to the stock headpipe for maximum gain as I've done w/the SBP system;
I didn't notice any increase in spit-back, that's an interesting question! I suppose it's conceivable given the effect of an expansion chamber... but even if there was it was so marginal I didn't notice & it'd be worth it anyway I figure. As for welding the stock muffler on the end... well... I suppose it'd depend on which muffler you've got. The catalytic mufflers belong in the trash can, they just load up with unspent oil & carbon and will defeat the purpose - but the just baffled ones should be aright *shrug* I't defo quiet it down a bunch
I run an extended glasspack for maximum flow, but some have added utility engine/lawnmower mufflers to help with the noise...
What about welding a long outlet pipe to the end of the Spooky expansion chamber that is bolted to the jug? Would I still have a performance increase? Im mainly looking for better mileage as I use this one for a commuter.