Wiring open an XB12 exhaust

Endopotential · Mar 24, 2018

I've got an '07 XB9 with what I think is a gutted out Hawk exhaust (stock muffler shape but two rear pipes).

Got my hands on a nearly brand new XB12R muffler for cheap, and wanted to give it a try. Wanted to make sure I understand "wiring it open" correctly.
And it seems that general consensus is that "open" gives best low and top end performance, with possible sacrifice in mid-range?

In its default state, is the actuator/exhaust closed? So if I want to wire it open, then spin that tab clockwise and fix it in place?

sinikl · Mar 24, 2018

I have an xb9sx with a uly (xb12) muffler on it (who knows why). I had the box off to fix a broken sidestand bolt and discovered the PO had "wired" it open with a plastic zip tie that melted (of course it did). In talking to Kevin at Drummer fab, he recommended leaving it closed, and a pdf of an exhaust shootout with dyno charts I found then (and cannot find now) backed it up. Big hole in the midrange if it's wired open. I'd leave it alone.

sinikl · Mar 25, 2018

Found the chart, but only by finding my own thread with difficulty (had to search my own posts! this is just like my IT job where I document something, then have to read my own documentation 6 months later, if only I could find it, lol)

Here's a BWB thread with a chart from another forum: http://badweatherbikers.com/buell/messages/32777/159899.html?1163476022

Rad Moment= torque measured at wheel
Rad Leistung= hp measured at wheel
Serie=stock (different colors for xb9 and xb12)
offen=open valve

Notice the huge hole with it wired open, but yes, you do get a boost low down and top end from wired open. The hole is big tho; i left mine shut.
Interesting that the 12 exhaust (shut) also gives a bit of a boost low and high, but the stocker is best where your bike lives most of the time if you're me.

njloco · Mar 25, 2018

Gutted out with two exhaust ports, might be a Special Ops muffler. I have one, not mounted yet and that is pretty much the same as you described, if so, that's a pretty good muffler but it does still use the exhaust butterfly.

GregoXB · Mar 25, 2018

On the XB9, there should not be any exhaust valve/servo, only the XB 12 uses the valve/servo. The dual port exhaust he has on now should not have a butterfly valve and it is most likely a Hawk or Special O.P.S for the 9. I think he wants to put an OEM muffler from a 12 on his 9 and wire the valve open, to simulate an OEM XB 9 muffler.

Endopotential · Mar 25, 2018

Thanks for the input guys, really helpful.

My old muffler does look like the Hawk / Spec Ops one by pictures, except it doesn't have any valve on top, so who knows what the heck it is.

sinikl, thanks for the graph. That makes a pretty good argument to leave things alone in the closed position.

Compared to my other bikes, the XB9 already feels like it has gobs of torque down low. Above 65mph the wind buffetting is pretty harsh without a big windscreen, so higher top speed isn't as appealing. Optimizing mid-range torque sounds just right.

Silverrider · Mar 25, 2018

Here is my 06 Uly pipe moded by Randy Hawk, Shows valve but No valve inside.

GregoXB · Mar 25, 2018

Yes of course. The XB 12 muffler will have the valve actuator.

Endo, if you are looking for midrange power/torque on an XB 9, if your running a Hawk or a Spec OPS now, as long as you have a proper tune/ECM, the performance is going to be about as good as it gets. Putting a 12 muffler with a wired open valve onto your 9 is not going to achieve much, aside from making your motorcycle quieter.

GregoXB · Mar 25, 2018

That's an OEM XB 9 muffler. A Hawk or Spec OPS version of that will look exactly the same, except it will be shorter and have two exhaust ports.

Silverrider · Mar 25, 2018

Greg, It will only have 2 ports if you ask Randy to do so. And it cost a little more he will cut out the valve lever completely per your request. I like the 2 ports its like stereo.

Wiring open an XB12 exhaust

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