I was thinking it might work better by replacing the cat with a smaller diameter pipe. The cat is pretty large, and it looks well-designed to have a minimal effect on flow. Most of the after market pipes have very gradual increments in pipe diameter. For example this Spark system for my gf's 300:
Why is the O2 sensor worthless now that I have removed the CAT?
As for the PAIR valve, here is a good explanation (although on a different bike):Why is the O2 sensor worthless now that I have removed the CAT?
Also: Being a Ninja noob I have never heard of the Kawasaki Clean Air System. Is this the same as the PAIR valve I mentioned in my 'weight reduction' thread as yes, I am thinking of removing this. Will add a picture I took on the wkd just to check we are talking about the same thing. Any thoughts on removing this?
Lastly, If someone is quoting you then that means you have said something thought provoking or noteworthy rather than something meaningless.
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Yes this is a good clip, have seen it before. Good to have it posted up for others though.As for the PAIR valve, here is a good explanation (although on a different bike):
https://www.youtube.com/watch?v=_xMykbzJWiQ
Brock is a pretty sharp guy, with years and years of racing/tuning experience. He breaks it down in layman's terms, I think.
It will throw a code upon removal, almost 100% assured. You can get this to go away, again, through the ecu.
It used to be called Kleen on the Kaws...but same function, basically, whatever they call it.
Yes, the ECU can be flashed to ignore the issue with removing the valve. Check 8:30 in the video I referenced. For my 14R, I ordered a resistor plug to make it "think" the valve is there...now if I could only figure out where I put that part, since we moved, lol!
Thanks for the link. The plate is $26.99 which is OK but the thieving sods want another $43 for postage to NZ!
Im just thinking will the part of the pipe be to open? will there be to much airflow and not enough back pressure? I know the aftermarket headers are actually bigger than the stock headers so im thinking it should be fine but im not sure, hows the throttle response? better or worse? is the torque lower ?
I felt the throttle response was slightly better and that it was pulling better through low and midrange but it was negligible.So im thinking of doing the same as you Kiwi, mainly due to being pulled over all the time, so doing it your way will allow it to at least seem like the cat is still there even tho its hollow
to late lol tore the CAT apart and ripped everything out, will weld back together at work in a few hours, at half a kilo loss and at least a 5% performance gain im sure it will be nice
just waiting for front sprocket and chain to arrive to install, wont be able to ride bike for at least 7 days until all the rain stops, either way when I do I will be able to test the sprockets and full exhaust system all at once this will now put me at 10kgs of weight saving as well hehe Just helped a mate install a full system on a R3 and im glad the 400 uses a CAT which is basically like a thicker pipe because that R3 cat is just stupid haha.
Sounds like a plan, what will you be running for back half of exhaust system?to late lol tore the CAT apart and ripped everything out, will weld back together at work in a few hours, at half a kilo loss and at least a 5% performance gain im sure it will be nice
Kiwi, did you find the actual cat only occupied about 3 inches on the O2 sensor side of the larger diameter section of the pipe?
Good tip. From my original post:Kiwi, did you find the actual cat only occupied about 3 inches on the O2 sensor side of the larger diameter section of the pipe?
I cut mine on the mid-pipe side first, with plans to cut on the weld at both ends, and noticed it was buried closer to the 02 sensor and header down pipes, so I cut on the weld near the o2 sensor......and found, using my 14" chop saw with a metal blade, that it was much harder to cut through than the other side(is the housing for the actual cat screen/disc titanium), as if I was cutting through titanium or something much harder than the steel header, requiring a slow cut speed.
Unless I truly dulled the blade that much quicker running it at a higher RPM then they call for, since my saw runs higher RPM and using a router router speed control dial will burn up the motor running at a lower RPM.
I did make the first cut without any cutting oil.........which running higher RPM I should have......shame on me, might have killed a $80 blade on one cut.....lol hopefully not.....
Anyway, I cut it open and found the actual honeycomb cat was about a 3 inch thick disc.
I was fortunate enough that exactly where I cut that front weld it cut into the welds for the cat inside the pipe and I taped it out in about 10 seconds with a large square punch.
I pushed it straight out the opposite side of the header pipe (so slip on/mid pipe) side as one solid part.
No honing, turning, drilling, cutting, hacking etc. to get it out.......was so darn easy I felt discouraged that cleaning up the cuts, welds and chamfering/beveling the edges of the cuts, to weld it back together will be the hardest part.......so I took a break from it for a few days.....lol
So a tip to others would be, if you cut it on the front weld, cut it on the weld but closer to the back side of the weld, you might also cut the weld for the inner cat screen and can just push it right out the other end
Dang....sorry I missed that.........mine must have been the lightweight racing edition.........there was only one cat inside mine
