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farmer67

is exhaust performance even noticeable?

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farmer67
For those of you that have added a full system can you really even say that you have noticed more power? I have read so many comments that seem like "I can't really tell if there is more power", "It might feel more powerful".... etc.... Has anyone done a dyno after exhaust, a refresh or fuel controller, and any air mods? TIA!

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magsz18
I felt a power loss after installing my exhaust. The system has no apparent leaks but there is definitely less grunt. Now, this is my subjective butt dyno so the info means almost jack shit. :) Keep that in mind.

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Riverfox
Nothing scientific about this observation but with my stock bike, doing a second gear wheel stand consisted of holding a steady 4,000rpm, I would have to lean forward and as I open wide open throttle I would lean back aggressively to get the wheelie. I have since installed the MIVV GT titanium high mount (w/baffle in), EJK controller, stock air filter but snorkel out and O2 sensor removed. Now merely grabbing a handful of throttle with no change in seat position or rocking back, the front wheel easily gets lofted skyward. So, yes, I can feel a noticeable difference. It pulls harder for sure.
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Cruizin
Typically, a full exhaust system loses a little low end grunt but adds little mid range and top end. Very little. But lets face it, people get exhaust for the sound and looks, not performance. That's why I went with the lower priced M-4 option because I have a really hard time spending $1000 on a noise maker.
 
If you want to be faster, suspension is the way to go. Power helps in a boring straight line, but in the real world, suspension is the way to go. That is why suzuki SV-650's and Supermotos often pass superbikes in the twisties, laughing like hell.
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JA50N
I have the Yosh system and I bought it for [HASH]1 sound, and [HASH]2 looks. I could care less about added power. If I wanted a faster bike, I would have bought a faster bike to begin with.
 
I also chose a full system because should I ever need to put the stock system back on I wanted to be able to do that. With a slip on, once you make that cut, your stock exhaust is useless as a stock exhaust. That is a big commitment.
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Riverfox
Nothing scientific about this observation but with my stock bike, doing a second gear wheel stand consisted of holding a steady 4,000rpm, I would have to lean forward and as I open wide open throttle I would lean back aggressively to get the wheelie. I have since installed the MIVV GT titanium high mount (w/baffle in), EJK controller, stock air filter but snorkel out and O2 sensor removed. Now merely grabbing a handful of throttle with no change in seat position or rocking back, the front wheel easily gets lofted skyward. So, yes, I can feel a noticeable difference. It pulls harder for sure.
P.S. With the baffle out it was much harder to just power up the second gear wheel stand. Put the baffle back in and the wheel stand was easier to pull. Everything I've been told is that the baffle in makes more torque or "grunt" down low but it inhibits the high end pull.  

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rabbit07
I've had an M4 slip on for 4 days and have been riding the piss out of the bike...since it sounds so good and the weather is finally nice!..I notice zero performance change from stock.
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cjymiller
In this youtube video, the two guys can confirm that a full system with no other changes does lose torque.
 

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JA50N
Confirmation of losing torque would be a video of a stock bike being dynoed, the stock exhaust being replaced the same day, and the bike being re-dynoed on the same dyno showing a torque loss somewhere on the overlaid dyno graphs. I see none of that in this video.
 
Like I said before, I couldn't care less about any small power increase/loss that a full system gives. However, this video is FAR from confirmation of anything except that the 2 bikes are different.
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cjymiller
Confirmation of losing torque would be ... the overlaid dyno graphs. I see none of that in this video. 
Like I said before, I couldn't care less about any small power increase/loss that a full system gives. However, this video is FAR from confirmation of anything except that the 2 bikes are different.
 
 
 

Yea its too bad they don't have quantifiable data in the video. Did you notice a change at all after installing your full yoshi?

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hobbs
Call me crazy if you must, but I noticed a positive gain after I installed my slip on and EJK. May mostly be the jet kit. I might even test ride a stock one at a demo days and see how it feels.
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JA50N
Yea its too bad they don't have quantifiable data in the video. Did you notice a change at all after installing your full yoshi?
I did not.  My bike has 400 miles so I hadn't really leaned on it hard before the system and really haven't done since the install either.  

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Cruizin
Go into the Dobeck Performance boards and you will see that they have posted some dyno charts for different exhausts that they sell with their fuel programmers.
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pattonme
> May mostly be the jet kit.
 
THAT is the money quote. Engines are just air pumps. Aftermarket exhaust makes one part of the system have higher flow characteristics. Torque is a function of valve timing, overlap and the interaction of both positive and negative pressure waves. higher-flow exhaust interferes with the dynamics such that much of the time torque is lost in the mid to lower bands where these waves are most useful. At high RPM you're just trying to get the damn gasses out as fast as possible so that's where it shines.
 
That said, some bikes have been ridiculously choked to comply with emissions regulations and mods can make a big difference. I don't believe the FZ07 is one of those. When you change one side of the pump you need to fix the other end to bring it back into balance. This is where jet kits or richer ECU maps come in.
 
If you change the exhuast, if you don't also change the air/fuel side you're completely missing the point and just wasted your money.
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phicurious86
My experience was that a yoshi exhaust didn't add anything noticeable performance wise, but it did make the bike sound significantly more badass and removed an aesthetic flaw with the stock exhaust.
 
Limited testing with the EJK has produced a noticeable effect on performance. All throttling has smoothed out and the bike seems to pull harder from 1.5-4k rpms.
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Riverfox
BAFFLE IN.....more torque down low....less breathablity on the top end
 
BAFFLE OUT.....pulls harder on the top end....less torque down low

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marthy
When I did the tune the bike has the same mid range but lost 2 HP without the DBK on the dyno... that's with both set up tuned with the EJK.
 
I know there's some logic in what you're saying, I was surprised of the result too.

BAFFLE IN.....more torque down low....less breathablity on the top end 
BAFFLE OUT.....pulls harder on the top end....less torque down low
 

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Guest Ralph
40 years in the the motor trade have led me to believe that a
conservative 90% of modified vehicles are slower, less pleasant to
drive/ride and drink more fuel than a bog standard one, they often
feel faster and more exiting to drive/ride but rarely are they really
any faster. People modify stuff for all reasons and if they are happy
with the outcome that's what that matters.
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JA50N
40 years in the the motor trade have led me to believe that a conservative 90% of modified vehicles are slower, less pleasant to
drive/ride and drink more fuel than a bog standard one, they often
feel faster and more exiting to drive/ride but rarely are they really
any faster. People modify stuff for all reasons and if they are happy
with the outcome that's what that matters.
I guess I associate with people that know what they are doing then because 100% of the modified vehicles I have owned or my buddies have owned have all been much faster than they were stock (and have the quantitative proof). 
I also know that the most productive mod to make to any vehicle to make it faster is the driver/rider mod.
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pattonme
It's always fun to go to a track with a stock exhaust motorcycle and pass the guy with a couple grand worth of mods (can, FI) on the inside or around the outside at such a speed delta that he can't catch you on the straight parts. Training, experience, and above all quality suspension make all the difference in the world.

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Beemer
How many people here race? Not many I don't imagine. I just want my bike to sound like the bad-ass it is, not looking to get bragging rights. Jeebus, a stock 300 Ninja sounds better (damn you Yamaha!) I don't race anyone and I'm not going to, so as someone else mentioned, maybe an M4 will be best and then I can use the $700 savings toward a lot of other nice things like a fender eliminator, a lower cowl, some Denali lights (the stock low beam sucks also), some frame sliders and still have some change for other goodies. Now that's power shopping! (thanks Mom)
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JA50N
Are you ok with destroying your stock exhaust? If so, then maybe the M4 is for you.

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rabbit07
Sick of the snooty attitudes here in regards to installing slip ons...
"OMG! Don't cut your stock exhaust!"
yea...you might get your fancy little bitch hands dirty

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rowdy
Sick of the snooty attitudes here in regards to installing slip ons... "OMG! Don't cut your stock exhaust!"
yea...you might get your fancy little bitch hands dirty
That seems a little harsh. That's why, if I was gonna cut my exhaust, I'd just hit the effin crap out of it with my fist until it split into two. ... It would keep my fancy little bitch hands form getting dirty. :) Then again,  I don't want to put some piece of Shet kludge ass aftermarket fart can on my bike either.
Just sayin'...
 
 
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mjh937
I would not want to cut my exhaust either, but I have no problem with anyone who does. I had a friends GTI exhaust sitting in my garage for months after we replaced it. We finally took it to the recyclers. I can see my bike exhaust doing the same if I decide to replace it so it probably would make more sense to cut it and do a slip on. I just like having the ability to put it back to stock if I want to, although I have no idea why I would want too. I still have the cantaloupe turn signals sitting on a shelf in one piece waiting to go back on (that is NOT going to happen).
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