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Discussion Starter #1
So I got an ECU studio mapping kit in order to enable the blipper on my EAS 2.0.

It was suggested I use the maps with the exhaust servo disconnected settings and remove the cables from the servo.

My exhaust servo works 100% and I am using stock pipes and silencer. What benefit would disconnecting the exhaust servo have? Would I not lose bottom end drive by having the valve open at lower RPM ? I imagine no benefit at higher rpm.

Lastly, if I did remove the cables, is the valve default position open or closed?

Thanks ?
 

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Default position: Open.

Benefit to disabling: None
 

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Default position: Open.
I think this is true for the F4 but I seem to recall with the F3 and they are sprung closed. No idea why but I think they are. It's an easy test on the Dyno the F4 lost 50% of power.

The kit maps / ROMs from MV are all designed for use without the exhaust servo and they do away with the fueling compromises generated by complying with emissions regs.

So if you want to use those maps / ROMs then that would be the advice. Clearly if you are dynoing the bike then you could stay with the exhaust servo Rom and tune from there.
 

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The F3 is sprung open by default. If you remove the cabling it will stay in the open position. The servo goes to the closed position however when off... maybe this is what you remember? I have installed an exhaust servo eliminator and cabling removed. Its open all the time.

With most recent stock tune and in the always open position with stock exhaust I have noticed an increase in deep sounds at idle and more pronounced backfire noises when downshifting and slowing down. More torque in lower rpm but that is my butt dyno giving the feedback. No change to wide open throttle at high rpm power.

If you are doing a stock tune and adding blipper and programming the servo out you can safely have the servo and cabling removed in my opinion. If you want to keep it on thats fine as well. You can always just use the power up top with more throttle and a downshift.
 

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The valve is sprung open, so if anyone has an error and it is shut, either the servo is stuck at the closed position or the valve has seized. The servo is used to close the valve at lower revs.

I disconnected mine because the servo failed. I serviced the motor and it works, but in it he end it was easier to remove the servo, cables etc.

They are not he most reliable of parts on most bikes.

I’m not sure if anyone has any definitive proof that removing it has any performance effects either way though?
 

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I got no proof for the F3, But i've seen Brock from Brock's performance closing and opening and actually removing the servo valve wires while doing a dyno run with a suzuki gsxr1000 2017.

And the valve is open in Neutral. When you kick the bike in first gear, the valve actually closes a bit to 25% or so to lower noise.
On throttle the valve will completely be open after 5000rpm if I remember that correctly.

And he did a dyno run with everything working as intended and a dyno run with the cables disconnected (valve always open)
In the end it was like 0.1 hp more and 0.1 more torque.

So basically nothing changes, and wont be noticable. But thats on the Suzuki, and who knows what it will do with the MV.
 

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The exhaust valves in the muffler (Honda, BMW) are noise emissions. Exhaust valves ahead of the muffler are there to improve torque curve (eliminate dips).

If you will take a moment to study some WSBK bikes and some MotoGP bikes you will discover that they also use exhaust valves controlled by the ECU for power delivery smoothing.

Brock's 0.1 hp gain doesn't show the torque curve changes.
 

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Perhaps a silly question and sorry if this was covered elsewhere but is there any risk to the engine when running valve fully open or while riding to dealership with the fault on? If not I'll just yank the cables since I've currently got the malfunction happening....
 

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Perhaps a silly question and sorry if this was covered elsewhere but is there any risk to the engine when running valve fully open or while riding to dealership with the fault on? If not I'll just yank the cables since I've currently got the malfunction happening....
In a word....No .
 

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Perhaps a silly question and sorry if this was covered elsewhere but is there any risk to the engine when running valve fully open or while riding to dealership with the fault on? If not I'll just yank the cables since I've currently got the malfunction happening....
Found this with a quick search.

"The purpose of this system according to the motorcycle manufacturers’ marketing departments is to create back-pressure at lower RPM’s to increase torque. Unfortunately, this probably isn’t the real reason; the true purpose of the exup valves is to meet noise and emissions regulations. The exhaust valves are partially closed at idle and low rpm to reduce noise, and closed again at the upper RPMs to meet peak noise and emissions regulations. The proof of this has been shown on the dyno where removing the valves and retuning the engine creates a flatter better torque curve. Additionally, in the USA, most bikes close the valve again at the upper RPM range, but in Europe they do not (different regulations) and the European bikes typically create a few more HP on the top end as a result."
 

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That is mis-information.
 

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Perhaps a silly question and sorry if this was covered elsewhere but is there any risk to the engine when running valve fully open or while riding to dealership with the fault on? If not I'll just yank the cables since I've currently got the malfunction happening....

Only if there is a change in exhaust note. If it's stuck closed then don't ride it until you disconnect it or check. You'll know if it's stuck closed as the when you rev it the exhaust will sound totally muffled.
 

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Found this with a quick search.

"The purpose of this system according to the motorcycle manufacturers’ marketing departments is to create back-pressure at lower RPM’s to increase torque. Unfortunately, this probably isn’t the real reason; the true purpose of the exup valves is to meet noise and emissions regulations. The exhaust valves are partially closed at idle and low rpm to reduce noise, and closed again at the upper RPMs to meet peak noise and emissions regulations. The proof of this has been shown on the dyno where removing the valves and retuning the engine creates a flatter better torque curve. Additionally, in the USA, most bikes close the valve again at the upper RPM range, but in Europe they do not (different regulations) and the European bikes typically create a few more HP on the top end as a result."
That is mis-information.
Can't be wrong...it's on the internet!:wink2:
 

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Thank's for the info, from what I can tell the valve isn't properly sync'd. I opened up the servo and gave it a spray of contact cleaner then tightened the cables, there was some noticeable slack in the lines. The valve moved smoothly by hand and was moving when turning the throttle. Had the code show up when sitting idle for a while but after refueling it didn't show up again. I'm guessing there is still some adjustment I could do on the cables....
 

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@MrTrogg: There are adjusters at the valve end of the cables. They adjust like a brake cable barrel adjuster. You can probably take any additional slack out at that end.

F3 Exhaust Valve Adjustment.jpg
 

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Yup, I should have been more clear. I did adjust them via that method however the loose wording in the manual suggested to not over tighten it. It's probably me just not doing it enough to get all of the slack out.
 

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Can't be wrong...it's on the internet!:wink2:
Never said or mentioned that it are facts.
Just a quick search.

Im sure esq'z me knows a bit more about it since he mentioned he worked on motorcycles in another post I read few weeks ago.
And ofcourse the earlier comment he posted.
 

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Do NOT over tighten the cables...you will damage the actuator. Only one cable actually pulls against the valve spring (which tries to open the valve...default, no cable position is full open). The other cable helps maintain proper opening position based on ECU signal. It is normal for one cable to have some slack.

The following information is based on the systems I am familiar with. I have not studied the MV system, but suspect it is the same as all the other ones out there.

There is a position sensor on the actuator. It is a 3 wire 5 volt sensor that tells the ECU where the valve is positioned, and the ECU then activates the servo motor to move the valve where it wants it.

At full open the voltage signal should be 4.2 volts +/- .3 volts. At full closed it should be 0.9 volts +/- .3 Or vice versa...I can never remember which.

You can disconnect the actuator connector and use a 9v battery to rotate the pulley to full open or full closed with the key on (yes, it will create a fault code, but that will clear when you plug it back in).
Then back probe the still connected sensor wires, adjusting the cables to achieve the correct sensor reading. You use a 9v battery so you don't smoke the actuator with big amperage from a 12 v bike battery or similar.
 

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Discussion Starter #20
OK

So in my case I have a ECU studio licence with the full OEM maps as well as the MV kit maps that don't have the exhaust valve setup.

Do I run the stock maps with the exhaust valve working or do I disconnect and run the MV Kit maps that supposedly don't compromise for environmental concerns?

I bought the kit to activate the blipper, if I can get better performance with a different map then I will do so. The issue is I don't know if removing the exhaust valve is a step forward or backward?

I blame esq'z me for this. Had my mind made up until you came planting your seeds of doubt...
 
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