i dont think it being off center is causing any problems as of yet. from what has been posted it seems to be hitting the walls but i guess they cant pin point where

 

I feel like it's the spring mechanism or something internal.

 

Just got my revised muffler on yesterday, so far so good as the rattle I was experiencing (at idle with A/C on only) is gone and I haven't been able to coax a rattle out of it even when I try

 

Here is my plan, hoping some electrical wizards can help out.
Run a regular good muffler with a y just before the muffler. Have a cut out on the Y that is switched to the TPS voltage.

What I need to get is a switch that triggers the cut out to open at a given voltage and then close when the voltage goes below a certain voltage. Of course its a little more complicated than that. The switch needs to open the cut out valve, then close it once the voltage goes down. The Switch needs to know the state of the cut out motor's valve, unless the system cancels itself with ignition off. Otherwise it might get 180 degrees out of sync.

I'm a little fuzzy on how the cut out's switch works. If you hold it closed till the motor reaches its travel or it opens itself when it hits a stop?

 

yes its the flapper flapping in the "wind", I have held the flapper still and the rattle stops.

 

I was talking about fitting it under the car in the cat area. With the in/out being off center, it would make it a hard fit.

nothere, the problem with electrical cut outs are the motor stays energized when it reaches the end of it's travel. You would need stop limits in place for both open and close.

Chris, I have to assume your car has cams, but I want to ask anyway. Do it??

 

thanks Dennis, so the hot rod guys just go by noise level to know when to shut the motor off?

that does add more complication.

 

I believe he meant off center was a problem for my cat-location application. Looks like I'm going to have to find another solution. I was really hoping not to have to throw the stock catback on

 

Maybe if Dynomax added a little shock absorber inside the spring, it would stop the rattle. Someone should sell a coilover upgrade for the Dynomax VT

 

Not sure I follow. Look at the QTP downpipe cutout. That unit has a controller that powers the valve to full open and then shuts off power, leaving the valve open. Push another button and it closes the valve and when it gets to closed, power is turned off again.

Leaving power on the motor while it is not turning is bad. It will burn out in no time. Think of rolling your window up and just hold the switch there... same idea.

You could wire on in with a momentary switch. Press and hold till it is open then let go of the button, press it down the other way to close it up.

 

For the people with the revised version on heavy lope cams, its the top portion of the valve plate slamming back closed. Its basically like clapping.


Here look at the picture. You can see that the top portion of the valve rests on the sidewall of the inner pipe. When the huge short burst of exhaust pulse comes from the heavy cams, it kicks the valve open. And the long pulse width allows just enough time for the tight spring to pull and slam the valve plate shut. That slamming shut causes the clapping sound.

 

Way too much work and would be too difficult to make work. Best thing would be boost or vacuum operated valve.

For those with heavy cams, I'd suggest cutting it open and tightening the preload on the spring some how. All you need to do is just create more tension so it doesnt open till you boost.


At the moment I still have the unrevised Dynomax VT muffler but the smaller than 4.0 version. I thinking of sending it back to jegs to replace for the larger but I cut proof of purchase label for the rebate. Maybe they will still accept it? After all it does rattle.

 

well yes, it is too much work. A lot depends on the switch itself. It shouldn't be hard to get voltage keyed activation. Its just being sure the switch/ power open at full stop.

Having the cutout self open/close at about 40% throttle position would be pretty neat.

they should take the muffler back, no matter what the box looks like. its trash to them

 

gotcha! my bad lol

 

Stock cams for now.