Reply To: Low-end exhausts – GT250R
Hey , upload a photo here as a test , there should be a bright yellow box above the reply box showing a tutorial link for picture uploads.
And show us the exhaust in particular ?
EFI bikes need a balance: sound + performance.
Instead of a very short “straight through” muffler:
Look for a slip-on designed for EFI bikes, tuned to maintain some backpressure while increasing volume.
Some aftermarket mufflers give a nice growl without killing midrange torque.
Avoid removing DB killers entirely. Some aftermarket options include removable baffles for track-only use.
In other words , as i have leaned over the years Black Widow Exhausts that are 400mm always gave the best sound and balance or Lextek OP1 350m long cans . EFI bikes need some backpressure—super short slip-ons can make them run lean and lose midrange torque. Keep a DB killer and use an EFI-friendly slip-on: louder sound without killing performance. Those fake akras are just “annoying” loud , but a proper slip on from the likes of Black Widow , 2Brothers USA (rare) , MTC , HAWK in my own experience have been excellent.
I also modified the baffle so that the overal hole size is about the size of a 10p british coin (forgot dimensions) , as an exit-hole too big in the DB killer meant it felt “flat” riding it , but too narrow is not good either. I experimented a lot , though my old previous bike was the Kawasaki ZZR400 , it did not care what exhaust it had (for the most part) as it makes its power much higher up (screaming inline 4!) , the twins on Hyosungs both GTs and GVs i own really prefer the torque at the early revs not to be disturbed , the GV was more frustrating but i am digressing.
The stock cans on all hyos are too heavy! – You could get a tiny acceleration gain (very tiny) but shaving off the weight by switching to”road legal , performance exhausts” , if it helps check ebay UK and find BSAU stamped exhausts (BSAU generally meaning for road use) but just loud enough to get noticed! – In UK , if an exhaust is too loud , the inspectors (MOT Test) will fail the bike if the guy hates it and issues papers to the owner to change it (before he can ride on the road legally again) we have to get our bikes checked every 12 months to make sure the bike is “road worthy” , but exhaust noise is just one of them, though some harleys are very loud and still get away with but i am digressing , its 10pm as i write this haha, i think my brain is going 😔
Hope my un-organized reply helps ?