Tailpipe Exhaust Valve Mod

Ridin'Dirty · 05-03-2018, 10:55 AM

Has anyone else blocked his or hers open besides me? I've concluded that this mechanically operated valve is strictly for noise reduction, while others have said everything from engine torque increase at lower RPMs to that it allows the cats to warm up quicker... don't know/don't care. Its no "golf tee mod" but it isn't difficult to do with a piece of stiff wire. The exhaust now sounds just a bit louder but with more of a pleasant, lower frequency pitch. Oh, and there's no rasp or burble to it, but best of all, there's also no drone at highway speed. Just nice to see both pipes blowin' smoke on a chilly morning during warm up. I think that the valves movement is powered by an electrical solenoid connected to a toothed rack since there are three wires present to positively open and then close the valve.
My concern was that I would throw a code if I just unplugged the electrical connection. I just loosened the 3-10mm bolts holding the actuator assembly just far enough so that I could remove the spring clip that couples both assemblies. Then I bent a piece of welding electrode (flux removed) that matched the width of the slot on the valve shaft into a "Z" shape, slid it into position in the valve's slot after fully opening the exhaust flap, then secured the ends of the wire to the mounting bracket by bending. Save the spring clip that you've removed - it's $10 to buy if you ever want to revert to OEM.
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ejw2011 · 05-03-2018, 01:18 PM

I did the mod, removing only the clip and tie down with wire. No dash errors but ran a diagnostics with my Carly app and indicated exhaust flap opened as an error. No big deal.

Ridin'Dirty · 05-03-2018, 01:25 PM

Hmm, interesting. I wonder how the car's computer would know that the valve is open without the spring clip being connected to the actuator? Did you unplug the electrical cable?

mr_lab_rat · 05-03-2018, 04:49 PM

I did it (removed the clip and tied it open with a safety wire).
No codes, no problems, enjoying nicer sound.

ejw2011 · 05-03-2018, 07:38 PM

No. Did not unplug any electrical plugs and was shocked Carly diag picked it up. It might be a sensor finding the flap in open position vs high rpm needed to open normally.

05-03-2018, 10:55 AM	#1
Ridin'Dirty Private First Class 60 Rep 173 Posts Drives: '93 'Beemer' R100r, '17 X1(S) Join Date: Apr 2017 Location: NW PA iTrader: (0)	Tailpipe Exhaust Valve Mod Has anyone else blocked his or hers open besides me? I've concluded that this mechanically operated valve is strictly for noise reduction, while others have said everything from engine torque increase at lower RPMs to that it allows the cats to warm up quicker... don't know/don't care. Its no "golf tee mod" but it isn't difficult to do with a piece of stiff wire. The exhaust now sounds just a bit louder but with more of a pleasant, lower frequency pitch. Oh, and there's no rasp or burble to it, but best of all, there's also no drone at highway speed. Just nice to see both pipes blowin' smoke on a chilly morning during warm up. I think that the valves movement is powered by an electrical solenoid connected to a toothed rack since there are three wires present to positively open and then close the valve. My concern was that I would throw a code if I just unplugged the electrical connection. I just loosened the 3-10mm bolts holding the actuator assembly just far enough so that I could remove the spring clip that couples both assemblies. Then I bent a piece of welding electrode (flux removed) that matched the width of the slot on the valve shaft into a "Z" shape, slid it into position in the valve's slot after fully opening the exhaust flap, then secured the ends of the wire to the mounting bracket by bending. Save the spring clip that you've removed - it's $10 to buy if you ever want to revert to OEM. __________________
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05-03-2018, 01:18 PM	#2
ejw2011 Second Lieutenant 94 Rep 287 Posts Drives: x3 F25 35i, x1 F48 28i Join Date: Aug 2011 Location: Planet Earth iTrader: (1)	I did the mod, removing only the clip and tie down with wire. No dash errors but ran a diagnostics with my Carly app and indicated exhaust flap opened as an error. No big deal.
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05-03-2018, 01:25 PM	#3
Ridin'Dirty Private First Class 60 Rep 173 Posts Drives: '93 'Beemer' R100r, '17 X1(S) Join Date: Apr 2017 Location: NW PA iTrader: (0)	Hmm, interesting. I wonder how the car's computer would know that the valve is open without the spring clip being connected to the actuator? Did you unplug the electrical cable?
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05-03-2018, 04:49 PM	#4
mr_lab_rat Major 565 Rep 1,092 Posts Drives: 2017 M2, 2018 X1 Join Date: Jul 2017 Location: Vancouver iTrader: (0)	I did it (removed the clip and tied it open with a safety wire). No codes, no problems, enjoying nicer sound.
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05-03-2018, 07:38 PM	#5
ejw2011 Second Lieutenant 94 Rep 287 Posts Drives: x3 F25 35i, x1 F48 28i Join Date: Aug 2011 Location: Planet Earth iTrader: (1)	No. Did not unplug any electrical plugs and was shocked Carly diag picked it up. It might be a sensor finding the flap in open position vs high rpm needed to open normally.
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