Dual Dynomax VT mufflers + S475
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I have a S475 front mounted in a 99 Bird. I'm running a 4" dp all the way back and wanting to have a free flowing exhaust that is somewhat mellow at idle and cruise. I was thinking of running the dp into a y that goes over the axle into two 3" Dynomax VT mufflers. These have a flap that's closed at idle/cruise diverting the flow through a fiberglass element before existing the tailpipe. The flap opens as backpressure increase to make it a straight thru muffler much like a bullet. Anybody use a setup like this or have any experience with it?
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Not a lot of info on these mufflers....
i run a single 3" VT muffler and it is QUIET. My wastegate spring pressure is 10psi with no muffler. With this muffler it droped to 8psi and It sounds as though it is choking the living hel out of the engine. It definately doesnt sound like it "opens up" EVER....
For a few days, i thought it was installed backwards so i checked and verified it's flow direction...... i also have a 4" bullet muffler after the VT... the next step is to install a cutout for the days that i want 2 psi back, or roughly 40hp...
goodluck!!!
i run a single 3" VT muffler and it is QUIET. My wastegate spring pressure is 10psi with no muffler. With this muffler it droped to 8psi and It sounds as though it is choking the living hel out of the engine. It definately doesnt sound like it "opens up" EVER....
For a few days, i thought it was installed backwards so i checked and verified it's flow direction...... i also have a 4" bullet muffler after the VT... the next step is to install a cutout for the days that i want 2 psi back, or roughly 40hp...
goodluck!!!
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those things are horrible, especially if you have a cam that lopes. it will open and close and it makes a ting type of noise every time it lopes. if you want something quiet go with oem ctsv or vette mufflers and install some cutouts to open up whenever you want the noise/power.
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I have no personal experience with the VT but I did research them a while back and there are way more negative reviews than positive. For what it's worth any straight through style muffler (ie Borla, Magnaflow, or Dynomax Ultra) will be relatively tame until you are on it especially with a turbo. I have dual Magnaflows on my car and it's very tame cruising around and I have a boost activated cutout for when I'm on it.
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I ran those on my suburban. Worked great. Get the ones designed for single exhaust setups though. The spring for the flap in the "dual" exhaust ones is too soft and will cause the flapping/ting noise under low load.
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Get a 4" cutout with an electric plate, neck it down at the over axle bend, and get a quiet 3" catback. SLP dual/dual mufflers are just about the quietest best sounding and can be found used on here for around $150 shipped if you're patient til one comes up for sale. Best of both worlds.
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Thanks for all the replies. Sounds like it's not the one for forced induction. What about the Borla Pro XS. Anyone running those. I know they are straight thru and are more mellow than the XR-1's.