Gen 2 exup for noise or power gain?

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JRO

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Mounted a Yoshimura TRC slip-on the other day and removed the exup cables. Since it was to loud for me (getting old) I re-monted the stock exhaust. Question, does the exup give any gains at all or is it simply just for noise control? if no gains I will not attach the cables again since exup is open by default.

Thanks for helping.
 
I know on the GenII the EXUP is there mostly for sound. What I'm not sure of is when you keep the cables disconnected, what position the valve is in, opened or closed? If it was in the open position you'd be okay. I'm sure someone with a GenII will let you know soon.
 
the default position of the valve is open. when i first got my fz, the previous owner had taken an aftermarket exhaust off but not hooked up the exup cables again. i wondered why it sounded so beefy for a stock exhaust but then realized the exup valve was open
 
Thanks for nice comments but they don't really answer the question.
Again, is there any power gains with exup cables attached and fully working exup or is it just for noise controll?
 
JRO said:
Thanks for nice comments but they don't really answer the question.
Again, is there any power gains with exup cables attached and fully working exup or is it just for noise controll?
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Sure they answer it. It's only for noise so therefore don't do anything for power at all. You can leave the cables unattached if you want or reconnect them. Makes no difference except for loudness.:sport12:
 
I have checked mine 15 ways from Sunday, and found that it stays wide open the entire time, regardless of RPM, engine load, temperature, speed, etc. So the stupid EXUP valve remains open, regardless of whether the cables are connected or not. This is for Gen II bikes. I think Gen I EXUP valves actually functioned somewhat.

Therefore, you cannot gain any power by hooking up the cables to your EXUP. It is spring loaded to stay open all the time.

I would have thought that the EXUP might help fuel economy under very light load conditions by closing slightly to reduce the amount of intake mixture pass-through due to camshaft "overlap" when the intake and exhaust valves are both open for a short period in the cycle. I went so far as to rig up a manual operation of the valve, and experimented with closing it slightly, but no gain in fuel economy. The entire mechanism is worthless.
 
theestate said:
Exhaust Ultimate Power Valve was developed for power by handling exhaust gases at different revolution speeds of the engine. It is not a gimmick for exhaust sound. The design is to create back pressure to compact the air/fuel mixture through resonance at all engine speeds.

This may help

Four-stroke power valve system - Wikipedia, the free encyclopedia
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This was true on the Gen1 FZ1, but not the Gen2. The ExUp valve on the Gen2 is for noise only. It's easy to prove. Just do some testing with and without the cables attached.
 
Logic

Perhaps for noise control, but isn't there cheaper ways to reduce noise than valves, cables, and motors. It is advertised as a power enhancement and the way it operates is to build back pressure at low rpm.

Like the initiator of this topic, my FZ1 come with a aftermarket FMF Apex slip on. It is too loud and attracts attention when it is not wanted. I reinstalled the stock muffler, but I am not certain if the cables are set right since I did not see them before the FMF slip-on installation. I followed the service manual, but I am nervous because the bottom cable--black--is a few threads from fully seated and the top cable--silver--is a few threads from fully extended.

fz1exupvalve.jpg.html]


theestate-albums-2013-fz1-picture3697-fz1-exup-valve.jpg



Not sure the picture syntax is correct, but the picture is in my album. I would be grateful if others reported if their cable adjustments are as extreme.

After riding with the stock muffler, I decided the noise is better than the drop in performance. Ordered a silencer insert from FMF to help control the noise.
 
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theestate said:
Perhaps for noise control, but isn't there cheaper ways to reduce noise than valves, cables, and motors. It is advertised as a power enhancement and the way it operates is to build back pressure at low rpm.
...
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Trust us it does nothing for power in the Gen II FZ1. Yamaha can say whatever they want. At this point they are just using it as a marketing tool.

And yes it's for noise control. More specifically to help the bike pass the EPA noise tests, which are very specific about speed and RPMs...
 
I had my exup cables disconnected when I bought the bike hadn't realised they where until I gave the bike a proper once over. I did approx 2k miles without the cables and when I connected them back up I noticed no difference in power or noise for that matter. Maybe the whole set up is just a gimmick or marketing ploy but it's hard to believe Yamaha would spend the extra money putting the system on the bike if it does sweet FA.
 
Bass Ackward

Happened to come across this thread. As for the picture showing the "extreme" adjustment I believe that is solely due to someone un-installing the two cables completely and reinstalling them. One of the cables is longer than the other. Looks like they are simply reversed. The ones in my bike were labeled a/b.
 
YZFRiderNY said:
I know on the GenII the EXUP is there mostly for sound. What I'm not sure of is when you keep the cables disconnected, what position the valve is in, opened or closed? If it was in the open position you'd be okay. I'm sure someone with a GenII will let you know soon.
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It has nothing to do with reducing sound. Its all about exhaust tuning/flow at specific points, and remains mostly open during operation. Everyone that's removed it (including myself) cannot tell it's been removed. You have no choice but to remove it when going to a slip-on. This will only add performance to the bike by saving weight, improving exhaust flow by removing the secondary catalytic in the stock muffler. Obviously, the exhaust tone will be louder with a slip-on -> Free flowing exhaust = more noise decibels.

Yamaha FZ1 EXUP in action in 6th gear.wmv - YouTube
 
For those who think exup valves are for noise only WRONG. I had a 1900 roadliner it had the exup in the header pipe you could run it without the stock pipe or the aftermarket slip on still had the same power and torque, its all about exhaust back pressure.
 
RKS said:
For those who think exup valves are for noise only WRONG. I had a 1900 roadliner it had the exup in the header pipe you could run it without the stock pipe or the aftermarket slip on still had the same power and torque, its all about exhaust back pressure.
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It's not the same for every bike. EXUP has existed since the 80s and has been used in different applications and different bikes for different purposes

Also, back pressure is one of those old terms that get thrown around wrongly:

Exhaust Back Pressure Myth Debunked

One of the most misunderstood concepts in exhaust theory is back pressure. People talk about it with no real understanding of what it is and what it's consequences are. I'm sure many of you have heard or read the phrase "Engines need back pressure" when discussing exhaust upgrades. Sadly, that phrase is completely inaccurate and a wholly misguided notion.
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RKS said:
For those who think exup valves are for noise only WRONG. I had a 1900 roadliner it had the exup in the header pipe you could run it without the stock pipe or the aftermarket slip on still had the same power and torque, its all about exhaust back pressure.
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Subject has been beaten to death. ON THE GENII FZ1 THE EXUP VALVE SERVES NO DETECTIBLE ENGINE PERFORMANCE ENHANCING PURPOSE. This has nothing to do with its use in other applications . . For instance it most certainly has a performance enhancing function in the GEN1 FZ1 . . .
Way to climb out on a limb for your first post!
 
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Interesting read as always ! I'm still convinced as a few others it does sweet F.A ... I have my stock can fitted without the cables and the butterfly wired so it cannot get sucked closed & tbh don't really notice any real difference from the Remus power cone I have , what I do notice is the bike runs so much smoother with the stock can & is more of a pleasure to ride.
At the end of the day I don't have to look at it ;-) !!
 
Dustin said:
It's not the same for every bike. EXUP has existed since the 80s and has been used in different applications and different bikes for different purposes

Also, back pressure is one of those old terms that get thrown around wrongly:

Exhaust Back Pressure Myth Debunked
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We are talking about Yamaha here they use the exup for intake and exhaust pressure , back pressure,exhaust tuning call it what you like all in the name of more torque at certain revs my 2010 gen 2 is bone stock and has nice torque from 2k rpm and up in part due to the exup .I know more can be had with different pipes fuel mapping etc but I think Yamaha has done decent job with this gen2 ,enough for this old dude anyways.
 
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