Kawasaki ZX-10R Forum banner

1 - 20 of 43 Posts

·
The Movie Goer!
Joined
·
6,849 Posts
Discussion Starter #1
I noticed with the stock header on the zx-10, that right where it connects into the mid-pipe theres this weird thing? If i'm not mistaken itz called the "butterfly valve" or somethin like that? It has two cables i think? What is that for? And when u get a aftermarket exhaust i guess full system? Does it have that same thing or what?
 

·
OMG Look at that squid!!
Joined
·
2,595 Posts
Ooooooo My Gawd.

Please tell me this ISN'T your first bike yO!
 

·
Still here
Joined
·
9,059 Posts
Zig- no aftermarket pipes don't have the valve.

It is either for controlling noise or adding low to mid range power via backpressure depending on what you want to believe. Removing valve can trigger FI light. Do some searches, been discussed ALOT.

That 9r/10r is going to be interesting for sure.
 

·
MIA Post Whore
Joined
·
8,727 Posts
search "exhuast valve" when you have a few days of spare time.

No valve on full systems. No straight answer on what is "really" for.

edit- damn I type too slow...
 

·
Registered
Joined
·
607 Posts
If I'm not mistaken, most if not all aftermarket headers don't have the butterfly valve. You can remove the cable on the stock system without triggering the FI light but you will need to leave the servo plugged in. I ended up cutting the complete butterfly valve out of my stock system and welding up the holes.
 

·
OMG Look at that squid!!
Joined
·
2,595 Posts
Credible or not in your minds... BUT the folks at AreaP told me to just leave the valve in when doing a slip on. I asked very specifically about mapping their pipe, keeping the valve and what not... He said their extensive testing showed no gain when removing the valve... Just FYI.
 

·
Registered
Joined
·
28 Posts
what valve is for

The valve stops flashback (rich flame)at the cat on decell.The cat would melt and clog without this.
 

·
Registered
Joined
·
2,976 Posts
The valve is there so that the bike passes noise emissions. A backfire every now and then would not hurt a catalytic converter. The exhaust passing through the pipe is as hot or hotter.
 

·
Registered
Joined
·
28 Posts
not tru

on lp gas hybrid vehicles that my co helps produce we use these valves to keep the cat temps down on rich decel.I would imagine the ones on the bike do the same.If you disconnect and ride with stock can the noise level is quiet but the can temp goes up.
 

·
Registered
Joined
·
607 Posts
euro1 said:
The valve stops flashback (rich flame)at the cat on decell.The cat would melt and clog without this.
Hum, that's very interesting. The first ride after completely removing the valve I noticed a little backfire. I thought it was because I didn't weld it up tight enough but I checked it out and it was as tight as a drum. Then after some high speed runs and quick de-acceleration I noticed I was shooting flames out. Most noticeable at night. I didn't notice any HP improvement but I love to tinker .
 

·
Registered
Joined
·
675 Posts
Ninja Dude said:
Hum, that's very interesting. The first ride after completely removing the valve I noticed a little backfire. I thought it was because I didn't weld it up tight enough but I checked it out and it was as tight as a drum. Then after some high speed runs and quick de-acceleration I noticed I was shooting flames out. Most noticeable at night. I didn't notice any HP improvement but I love to tinker .

:dontknow: Uhhh....N D, how in the world are you driving at night looking at yer exhaust for shooting flames??? Aintcha supposed to be looking where you are going instead of where ya been??? :heyyou:
I bet you are riding with yer buddies, and they are always looking at the back side of yer bike right??? You musta shot one of em with a little sparky...hehehhe
 

·
The Movie Goer!
Joined
·
6,849 Posts
Discussion Starter #12
DarkAngel said:
:dontknow: Uhhh....N D, how in the world are you driving at night looking at yer exhaust for shooting flames??? Aintcha supposed to be looking where you are going instead of where ya been??? :heyyou:
I bet you are riding with yer buddies, and they are always looking at the back side of yer bike right??? You musta shot one of em with a little sparky...hehehhe





lol!!!!! classic!!! :crackup:
 

·
The Movie Goer!
Joined
·
6,849 Posts
Discussion Starter #13
ZX10Miami said:
Zig- no aftermarket pipes don't have the valve.

It is either for controlling noise or adding low to mid range power via backpressure depending on what you want to believe. Removing valve can trigger FI light. Do some searches, been discussed ALOT.

That 9r/10r is going to be interesting for sure.





No doubt man! Thanx for the info!
 

·
The Movie Goer!
Joined
·
6,849 Posts
Discussion Starter #14
Thanx fella's 4 offering ur wordz of wisdom on this issue. Appreciate it! :eek:ccasion1
 

·
Banned
Joined
·
808 Posts
Yamaha has EXUP system, and i believe kawasaki also has same thing there...its the valve that changes exhaust pressure and gives more power below 5000rpm~ If you remove it, your power will be lower there and thats it. If you put aftermarket full exhaust sistem, then you won't have good power in low range rpm (racers don't need it anyway) but more power on high rpms.If you are riding on the street, just buy slip-on and that will be best price/power/sound combo.And leave that valve there.
 

·
Registered
Joined
·
63 Posts
I have seen a few graphs on here and also from the shop where I got my bike and the concensus is that the valve is only there for noise, with it operational or not there is no difference in power anywhere in the power band :headshake

The whole backpressure improves low down power is a myth imho, if anyone can find me a site showing me details of how putting a restriction in the exhaust system improves power I will gladly read it :idea:
 

·
Registered
Joined
·
1,945 Posts
DarkAngel said:
:dontknow: Uhhh....N D, how in the world are you driving at night looking at yer exhaust for shooting flames??? Aintcha supposed to be looking where you are going instead of where ya been??? :heyyou:
I bet you are riding with yer buddies, and they are always looking at the back side of yer bike right??? You musta shot one of em with a little sparky...hehehhe

I've seen the glow from flames coming out of my slip-on as well. I notice them out of the corner of my eye when I'm leaned over 45-50 degrees on the cloverleafs. :mrgreen:
funny thing is I still have the exhaust vaslve installed in my exhaust. I am running a slip-on though.
 

·
Registered
Joined
·
2,620 Posts
busaforhire said:
I've seen the glow from flames coming out of my slip-on as well. I notice them out of the corner of my eye when I'm leaned over 45-50 degrees on the cloverleafs. :mrgreen:
funny thing is I still have the exhaust vaslve installed in my exhaust. I am running a slip-on though.

Thats cause the Catalyst is missing now........
 

·
Registered
Joined
·
607 Posts
DarkAngel said:
:dontknow: Uhhh....N D, how in the world are you driving at night looking at yer exhaust for shooting flames??? Aintcha supposed to be looking where you are going instead of where ya been??? :heyyou:
I bet you are riding with yer buddies, and they are always looking at the back side of yer bike right??? You musta shot one of em with a little sparky...hehehhe
Damn man you busted me out. :crackup: :crackup:
 
1 - 20 of 43 Posts
Top