Active exhaust valve on a 2012 Fat Boy.

Duckman-Si

Duckman-Si

Club Member
Hi Everyone,

My apologies if this has been covered before but, I can't seem to find the answers I need on other threads.
I have a 2012 Fat Boy which has the active exhaust valve & intake.
When I bought the bike from the original owner, it came with a Diag 4 Tune USB dongle, in an envelope marked "stage one tune" I have paperwork from Sycamore H-D listing a Stage one filter, along with the Diag 4 tune & an Eliminator kit (VH31001) the valve on the exhaust pipe is Permanently open & from what I can tell, the wiring to the actuator motor, is disconnected with a "bung" in place which, I assume is what the Eliminator kit on the invoice is??
Does all of this point to & confirm a stage one tune?
If I have understood things correctly, there should also be a "bung" somewhere on the air intake but, I'm not sure where I should be looking, is it an obviously visible piece? Or do I need to remove the cover to check it's there?
I'm asking all of this as I want to swap the stock headers & the V&H slip-ons that are currently fitted, for a set of V&H big shots.
I am trying to figure out, if the Diag4 tune that is on the bike, will be okay to run the big shots or, do I need to re-tune the bike??
I've tried my local H-D dealer but, they were no help at all so, I thought I would ask you guys...
I've added a couple of pictures, in the hope it helps someone answer the questions.
Thanks in advance for any possible advice.
Si.



1000005153.jpg1000005154.jpg1000005119.jpg1000005115.jpg
 
Sounds like the kit was to hold the exhaust servo open and the tune was to compensate for this mod as at low revs the servo would be almost closed to offer backpressure/torque benefits and undoubtedly to do with meeting emissions as with many motorcycle manufacturers using exhaust servos.

If you only have slip on's currently, then the catalytic convertor will still be in the exhaust, so swapping to a fully open exhaust will mean you remove any cables from the servo actuator etc and would need to re-tune as you will no longer have the restriction of the catalytic convertor in the pipe.

Options would be to take it to your HD dealer to re-map the fueling or buy something like a Dynojet Powervision 2 and get it mapped on a Dyno. This way would be far better than a generic map that HD will likely download and flash your ECU with.

If you have a mate with a PowerVision, FP4, or similar, often you can buy a license for the fueler and get a map downloaded via Vance & Hines. This could be the cheapest way to get your bike set-up. V&H used to have a section for MAP downloads, but it appears they no longer offer this so I assume this was to ensure you wen to a Dyno/Dealer to obtain the MAP.
 
From the description it sound like the standard pipe is still in place, if so changing to V&H long shots will need a re-tune regardless of a CAT.
 
Dazzlin said:
Sounds like the kit was to hold the exhaust servo open and the tune was to compensate for this mod as at low revs the servo would be almost closed to offer backpressure/torque benefits and undoubtedly to do with meeting emissions as with many motorcycle manufacturers using exhaust servos.

If you only have slip on's currently, then the catalytic convertor will still be in the exhaust, so swapping to a fully open exhaust will mean you remove any cables from the servo actuator etc and would need to re-tune as you will no longer have the restriction of the catalytic convertor in the pipe.

Options would be to take it to your HD dealer to re-map the fueling or buy something like a Dynojet Powervision 2 and get it mapped on a Dyno. This way would be far better than a generic map that HD will likely download and flash your ECU with.

If you have a mate with a PowerVision, FP4, or similar, often you can buy a license for the fueler and get a map downloaded via Vance & Hines. This could be the cheapest way to get your bike set-up. V&H used to have a section for MAP downloads, but it appears they no longer offer this so I assume this was to ensure you wen to a Dyno/Dealer to obtain the MAP.
Click to expand...
Thanks for the reply,
It looks like, I'm going to need to start from scratch then really...
I guess the best thing to do, is go to my harley dealer & see how much they will charge to re-tune the bike.
I'm thinking an FP4 might be the cheapest option?
 
The Active Intake servo valves were introduced on HDI models only around 06 model year and active exhaust servo valves for the purpose of noise reduction basically to pass the EU noise tests, they serve no other function if they really did optimise performance they would have been fitted on USA domestic models too, they weren't. They hamper performance, the servo intake valve was dropped on later models whilst the exhaust valve persisted until the M8 incarnation on the Softail!

Basically if you remove them you will get a an Engine warning light & fault code saying they open circuit, so all the eliminators do is put a resistor in to simulate the coil in the servo is still there.

The other way is to flash the ECU to say basically they are not there so it does not look for them, so no fault codes!

You have a good picture of the eliminator on the active exhaust wiring plug, so all good there!

Act Ex.jpg
So if the air cleaner has been replace with anything other than the OEM plastic back box see, below the eliminator will be plugged into that part of the wiring loom and most likely tucked under the tank out the way.

Screenshot 2024-03-08 092839.jpg
1709891809758.png

If you replace your Stock headers and V&H slip-ons with big shots to run its best it will need re-tuning, it may run reasonably well without but it may not. You should need to do nothing more to the wiring with the eliminators, and just remove the exhaust servo valve motor.

Possible other options, you get a V&H tuner or similar that will have canned maps for you proposed set and use that, this will also be able to read the fault codes etc & turn off the Servo Valves for good without the need for eliminators or go for a Dyno flash tune, which would result in the best running for the set up you use.
 
SJC69 said:
The Active Intake servo valves were introduced on HDI models only around 06 model year and active exhaust servo valves for the purpose of noise reduction basically to pass the EU noise tests, they serve no other function if they really did optimise performance they would have been fitted on USA domestic models too, they weren't. They hamper performance, the servo intake valve was dropped on later models whilst the exhaust valve persisted until the M8 incarnation on the Softail!

Basically if you remove them you will get a an Engine warning light & fault code saying they open circuit, so all the eliminators do is put a resistor in to simulate the coil in the servo is still there.

The other way is to flash the ECU to say basically they are not there so it does not look for them, so no fault codes!

You have a good picture of the eliminator on the active exhaust wiring plug, so all good there!

View attachment 1200088
So if the air cleaner has been replace with anything other than the OEM plastic back box see, below the eliminator will be plugged into that part of the wiring loom and most likely tucked under the tank out the way.

View attachment 1200089
View attachment 1200090

If you replace your Stock headers and V&H slip-ons with big shots to run its best it will need re-tuning, it may run reasonably well without but it may not. You should need to do nothing more to the wiring with the eliminators, and just remove the exhaust servo valve motor.

Possible other options, you get a V&H tuner or similar that will have canned maps for you proposed set and use that, this will also be able to read the fault codes etc & turn off the Servo Valves for good without the need for eliminators or go for a Dyno flash tune, which would result in the best running for the set up you use.
Click to expand...
Thanks so much SJC69, you have really helped me there.
from what i can gather the air cleaner is stock, well the housing at least, so i guess i would need to open it up and see whats in there??

would it be okay to drop you a private message? as your knowledge woul be much appreciated.
 
Duckman-Si said:
Thanks so much SJC69, you have really helped me there.
from what i can gather the air cleaner is stock, well the housing at least, so i guess i would need to open it up and see whats in there??

would it be okay to drop you a private message? as your knowledge woul be much appreciated.
Click to expand...
That invoice suggests they fitted a Screaming Eagle or similar Air Cleaner Kit.

PM away. (y)
 
Halal Tim said:
Depends on how you ride, and what you use bike for?

Solo, 2 up,

Low down torque, top end?
Click to expand...
99% of the time I ride solo. I'd say 80% of my riding is around town or on A roads, the remaining 20% being motorway.
I guess low end torque, would probably be more useful to me...
 
watchman said:
Did the 12 plate fatbobs have cats in em ? Or did it come later
Click to expand...
Cat's were being fitted since 2006, either in the header pipes or in the mufflers. I never had my standard exhaust on my 2016 Fat Boy long enough to even think of looking and pinpoint where they were on that model :ROFLMAO:
 
Dazzlin said:
Cat's were being fitted since 2006, either in the header pipes or in the mufflers. I never had my standard exhaust on my 2016 Fat Boy long enough to even think of looking and pinpoint where they were on that model :ROFLMAO:
Click to expand...
Is there a way of telling?
 
Duckman-Si said:
Is there a way of telling?
Click to expand...
I guess the only way to be 100% sure would be to remove the slip on's and using something like a long welding rod, slowly insert up the header section and if you hit resistance before getting near the exhaust clamp area, the chances are it's in the header. Note there is an O2 sensor in the header section, so ensure you pass this.

If no resistance is felt (ie. nothing stopping the rod going further) the chances are it's in the original silencers. I remember they were pretty heavy when I removed mine some years back, so I think there is a high chance they were in there on the Fat Boy so you may already be Cat free with the V&H slip on's.
 
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