Does Anyone Know What This Valve is Called or What It Does?

[Jeff_]

I've been told I shouldn't do this mod to keep it permanently open if I don't have AFM disabled otherwise it'll sound like ****. Is that truly the group consensus?

 

[STORMIN08]

it does sound odd in V4 mode.

 

[iamdub]

I've been told I shouldn't do this mod to keep it permanently open if I don't have AFM disabled otherwise it'll sound like ****. Is that truly the group consensus?

Which will sound shittier- the constant metallic rattling or an odd engine note only when in V4 mode?

 

[WillieFlo]

i hose clamped that dude wide open long ago...helps keep it from rattling as it gets weak

So, when the vehicle is off, I assume that spring pulls it into the "closed" position? When the vehicle was off, I could turn it about 5-10 degrees in one direction, and the other direction it rotated about 90 degrees. So, I held it turned in the 90 degree position while I wired it like that. Hopefully, that holds it open, but just want to confirm that was the correct assumption. No more rattling on startup.

I have the Borla exhaust on mine and am interested to see what it sounds like in V4 mode on the Highway.

 

[iamdub]

So, when the vehicle is off, I assume that spring pulls it into the "closed" position? When the vehicle was off, I could turn it about 5-10 degrees in one direction, and the other direction it rotated about 90 degrees. So, I held it turned in the 90 degree position while I wired it like that. Hopefully, that holds it open, but just want to confirm that was the correct assumption. No more rattling on startup.

I have the Borla exhaust on mine and am interested to see what it sounds like in V4 mode on the Highway.

Yes. The spring tension is balanced so that the air volume when running on all eight cylinders keeps the valve open. When running on fewer cylinders, the engine is pumping less air. A full-open exhaust sized for a V-8 but with half that volume going through it is like the typical oversized free-flowing exhaust on a compact car ("import") with a fart cannon. With the engine off/no air flowing through the exhaust, the valve would be at its minimal position. I doubt this would be "fully closed" as that would be pointless, but it'd have to be against a stop of some sort.

 

[BigBlueLB756]

It's So easy.

 

[17 Yukon Denali]

It's a Dinglehopper. EVERYONE knows that,

 

[OR VietVet]

It's a Dinglehopper. EVERYONE knows that,

Well, we do now.