CBR Forum - Enthusiast forums for Honda CBR Owners

- How-To: Mechanical (https://cbrforum.com/forum/how-mechanical-40/)

- - shorty exhaust how to (https://cbrforum.com/forum/how-mechanical-40/shorty-exhaust-how-71596/)

Quote:

Originally Posted by 600ninja (Post 872290)

what does that do to your exhaust note? and did you re tune ur carbs?

Mine got deeper. Also noticably louder. I like it. But I'm also an asshole... Lol

Quote:

Originally Posted by devlzluv (Post 605028)

lol not sayign anything bad about doing this but no backpressure on ur motor will burn ur valves, you will understand when u have to rebuild ur motor but if you dont understand what your talking about plz dont tell other people that it will not effect there motors. yes are engines can run with little to no back pressure but its not made to and will effect your motor in the long run. You can make a shorty exhaust if done properly with the proper baffling in it and not effect ur motor and still ge tthe same power output.

as long as you adjust fueling to match you don't have to worry about it, i'm pretty sure that people who are shortening their exhaust aren't matching fuel though. bad news, +1 it will damage in the long run, -1 no one here can make an exhaust that will keep real power esp. via a shorty pipe. also, theres a reason aftermarket exhaust are the length they are, flow velocity and length of the system are extremely important for gettting max power using an effect similar to a 2-strokes scavenging.

I dont think that anoyingly loud exhausts "save lifes" Even with a stock exhaust at freeway speeds you can hear a sportbike. But that my .02

2002 and newer F4i's do not have carbs. It is a fuel injected system. Computer regulates fuel/air mixture. After cutting the Yosh RS3 I had a full tune-up done on it. They also installed a K&N filter.
The boys at JP Motorsports did an awsome job.

i have a 929 with a yosh rs3 can if i cut from the bottom end of the can at 8 in ,all i have to do is cut right ,no welding on the inside just rivet back together correct?

you could re-drill rivet holes and rivet the bottom back on, wouldn't recommend cutting from the bottom though. my v&h had a solid welded exhaust mount bracket, had to chop it off from the top.

i'm loving my exhaust, didn't chop off to much it looks perfect. packed it properly its a bit deeper toned and throatier, i'll take pictures and videos later.

ok i did this some time ago and thought id throw in a few pics and add to the "HOW TO"
Mine was a d&d can. i simply marked on the can the 6 inches i wanted to cut off, then used a chop/mitre saw with metal blade for a dead straight, easy cut. that bit took about 2 minutes after i had the can off the bike. heres a pic...
Attachment 45478

Then i had to remove the inner tube and wadding from inside. it all came out with a firm pull with grips/pliers.
Attachment 45479
and i was left with ....
Attachment 45480
then i used an angle grinder and ground the rivets down and pushed them through with a spike....
Attachment 45481
then the end tapped out!
Attachment 45482
the end just slotted back into the new shorter can, and i drilled and riveted back together.
I only took off 6 inches, have not noticed any performance either way and it definately looks and sounds a million times better! judge for your self with the next two pics....
before...
Attachment 45483
after....
Attachment 45484

nice work.
i did this with my carbon slip on, very easy job, looks much nicer with a small can.
it was shortened with 14cm :)

edit:

and now it has been shortened 3.5cm more at rear :P in total 17.5cm :D

Just did my exhaust and love it