Not sure if this has been discussed before...

From the Harley Service Manual about the Active Exhaust Valve on (international spec) bikes:

The active exhaust system utilizes an actuator valve located in the rear exhaust pipe which is connected to a servo motor via a cable. The valve position automatically adjusts to enhance engine performance.

This sounds like the systems used on Jap sportsbikes, e.g. Yamha EXUP, etc. for boosting low-speed torque.

However, I heard that on our bikes it's just for noise reduction.

Anyone know what the deal is with this?

I am putting on some new mufflers and am wondering whether I should disable it, but I do not want to sacrifice any grunt down low.

Below some pics of the valve in my bike at different positions: closed, slight openeing and fully open.

make it go away and never look back

Fuck, if I could rig one of them up and make it so I could adjust it (push button) manually I would in an instant. You could lower the noise when being pulled over or turning into you home street and ramp it up on rides. Sweet.

Btw, it isn't just about noise I believe. The closed valve creates back pressure which turns into more (or at least, the correct amount of) torque. Opening up the valve prolly makes it breathe easier at higher speeds.

Yes available and I have one. It's a patriot defender. Mine is black with chrome heat shields for a softail if anyone is interested in buying it

I've seen the defenders, but I didn't like the sound - open or closed. Most of the other solutions don't have actuators so you have to manually turn them. Maybe I'll build my own one day

Like I said before though, an open/closing system is a good thing as long as you're in control of the opening and closing. You can adjust the note/db level and get back some of your torque when you need it.

This system was for noise reduction in European models for " drive by" noise testing. Made the bike a 2 into 1 thru' a restrictive muffler at certain road speeds

Because "Aussie bikes" are sold as HDI ( Harley Davidson International ) we get lumbered with the same system as the Euros

At first I just used to wedgie them open with a self tapper or rivet , later on I would "disable" them in an ECM reflash ( I still do as a matter of course )

It has been discussed many times back to 2007 on the forum , and is better "off" by whatever means for performance

If you disable it in the pre flash settings it wil still open and close when the bike is out of gear and it's revved.This is what I did. Flash a cal with Active exhaust enabled, start the bike, the flapper will open 100%. Disconnect the plug going into the actuator whilst the bike is running. The flapper will stay open when you turn the bike off. Now flash the cal again with Active Exhaust disabled. The flapper will be open at all times. I also maxed out the tables to 100% just to be sure but I don't think that's necessary.

Guys,

Need to see a photo of the exhaust

Remove it and the cat and don't look back

Gday Ratbob, I done it to a 103 Ultra to get rid of the heat from the cat. Lost a bit of bottom end but not so much an issue for me because I'm usually cruising at 100 plus.