silentbravo

iTrader: (1)

Ya I already have it. If I have to stack mufflers then so be it, but it has to be an improvement of what I have at the moment. I have quite a bit of room under my truck, with a crew cab...

Good thing we have members who can experiment with these things and let us know how it works beforehand (hopefully with sound clips)

dantheman1540

Ok my area to play with is
Drive shaft-frame rail is 18"
Crossmember bend-axle bend is 28" of muffler case max!
Floor boards to bottom of frame rail is 9"

So 5x11s will hang down too low but 5x9 is a possibility but that's really cutting it close.
I'd like to keep the case length to 24" because 28" will make it difficult to weld and generally be a PITA.

So current thoughts and I'd like to order something by tomorrow morning so it shows up this week.
1: Dual Magnaflow #13742 7" round 24" case chambered but straight though mufflers.
2: Dual Magnaflow #12279 5x8x24" straight through

I'm leaning towards the 7" because I think the chambers might help more with the drone and they are overall bigger.

dantheman1540

Crewcab oh boy you have double the field to play on. When you get it done just add sound clips to this thread and even better use a decibel meter to give us a shot at understanding how loud it actually is.

Also If you end up doing stacks on stacks on stacks, Let me know I'll donate another 12599 cheap. If 1 x pipe is good then 2 are even better right?

dantheman1540

I spoke to Magnaflow and they told me the 7x7x30 is chambered and has no packing so it is loud, raspy, and will be louder than my current setup. They said the quietest muffler they have is the 12589 which is a 5x11x22 single I/O but that will only be a little quieter than what I currently have and won't fit without hanging below the frame anyway so that's out.

Then I spoke to Flopro who was much more knowledgable on their products. I asked about the differences between the three different 9x11 big oval mufflers they have and the salesman told me "The 2505 does not neck down inside like the other 2 models, it also has significantly larger perforations in the baffles tubes, and more importantly the inlets and outlets are in line. The other 2 models have one outlet that is offset causing the majority of gas to exit one outlet until the flow overcomes the restriction with throttle causing them to flow from both. Another cool point on the big oval series is that although it's not technically an X/H pipe both pipes do interact with each other and should produce similar scavaging effects.

I ordered a 2505 and it should be here and installed Friday.

dantheman1540

Finally got the 2505 installed and now I can think again. According to my decibel meter idle inside the cab is still 81 and WOT dropped to 87 but it sounds considerably quieter than that. I suppose it just eliminated all the drone and resonance which made it seem louder than it was. Idle still sounds great outside but inside I can hear the faint whine of the NV4500 synchros debating on what gear ill dump the clutch in. Post clips later I suppose.

dantheman1540

_zebra

iTrader: (5)

what's with all these folks who turn the camera sideways when they take pictures/videos nowadays?

dantheman1540

Idk, this was taken with the camera straight up and down.

silentbravo

iTrader: (1)

What app are you using to check sound levels?

tjmath

@dantheman1540 drive that pile to AZ so I can hear it in person. Can't tell if I like the Magnaflow or the Flopro better. Need to hear it live and in person.