Well, I've had my Magnaflow exhaust on my truck for about a month now. I'll be honest, by replacing my Flowmaster, I got was I was looking for--the exhaust is much quieter in the cab, with no more drone out on the highway. But, the tone of the exhaust is less than stellar. At an idle, or blipping the throttle at idle, it sounds nice, revving out is ok, but everywhere in between (read: daily driving) sucks. "Deep & powerful"? More like a long wet fart. The FM 50 gave the 6-popper a very un-characteristic sound, that *was* deep & powerful.

But, here's the thing. I'm thinking pipe diameter might be playing a part in this. My FM setup was 3", exit in front of the rear tire with a 3.5" tip. There were no drastic bends, only one very slight one. The piping I have now is 2.5" all the way, over the axle, exit behind the wheel, 3.5" tip. But, when I got to looking, the bends the shop made to get it over the axle are quite severe, and it looks like the pipe is necked down to under 2" in the bends!! I'm not pleased with how they routed the pipe at all, it looks quite restrictive. Maybe thats contributing to the wet fart sound.

So, now I'm thinking, would it be possible to get a little deeper tone by having a peice of 3" pipe, bent a little nicer up over the axle, topped off with a 4" tip?

 

What size flow did you go with? And those nasty bends could affect the sound.

 

I put a 5x8x18 muffler on.

 

I'm not positive, but I think longer tips usually create deeper sound. It's all physics really. Higher pitched exhaust notes virbrate more frequently, a deeper (lower) note vibrates less frequently. Also, the materials used and the diameter would definitely play a role in how your exhaust sounds. Any expert at an exhaust shop should know the recipe for the deeper exhaust notes, but that will be whatever creates the lower frequency. Hope that helped.

BTW, I don't think the bends in the piping are going to make or break your exhaust sound. My friend has a truck almost identical to mine and his exhaust exits out the rear and has a couple of big bends over the axle, whereas I have turndowns before the rear axle with no bends after the first cat. We both have 40 Series Flows. He gets his deep rumble from his long 3.5" tips, I get my rumble compliments of the pavement.

 

Just noted your muffler size. The shorter your muffler, the louder your exhaust will be. I believe Magnaflow has a 14" muffler, which would be my muffler of choice. My brother has an '03 Z71 5.3 with the shortest Magnaflow muffler on it. It sounds deep but tame at lower rpm's but has an appreciable roar at WOT.

 

I think your problem is that 18" muffler. I went with dual 14" ones. TF is right...the bigger and longer the tips the deeper the tone.

 

Well, I think the first thing I'll try is having a different tail pipe made. Also, the shop that did the work put the muffler extremely close to the axle, so the pipe has to bend damn near straight up where it exits the muffler, creating another ridiculous restriction.

So, I'll see if they will move the muffler forward a few feet, mate a 3" pipe to the oulet of the muffler, make a couple milder bends over the axle, and top it off with a 4" tip.

BTW, my exhaust has no longer has *any* cats. The main cat was removed long ago, and I had the stock Y pipe off the manfold replaced with a Walker pipe, which did not have a cat on it.