Lookin to buy Muffler for my HD

2001Silverado2500HD · August 6, 2005

What do you guys reccomend for my 01 2500HD Crew Cab. 6.0L What will give me more performance wise, dual in- single out, single in single out? What series flowmasters do you guys reccomend? Thanks alot, im lookin to get this dont within the next 2 hours so any input would be nice. thanks

Frank S · August 6, 2005

The 50 series big block Flowmaster is what most shops recommend if you're not going to be replacing pipe. That's what i have on mine and kept all of the factory stainless with just a few small splice pipes to adapt it. This muffler is VERY loud and causes a lot of in cab resonance. Most people go with the Magna Flow instead which doesn't resonate quite as much.

mmmikkke · August 6, 2005

The 50 series big block Flowmaster is what most shops recommend if you're not going to be replacing pipe. That's what i have on mine and kept all of the factory stainless with just a few small splice pipes to adapt it. This muffler is VERY loud and causes a lot of in cab resonance. Most people go with the Magna Flow instead which doesn't resonate quite as much.

<{POST_SNAPBACK}>

Resonance is my pet peeve. One of my theorys regarding resonance is that a cylindrical muffler is less likely to flex its sides, relative to a muffler with an oval cross section. The few times I've replaced mufflers, trying to minimize resonance, I've seen a correlation.

When the cross section is cylindrical, the sides of the muffler can't flex as a result of pressure pulses inside, because a cylinder is already optimal and there's no place for the pressure to be relieved.

With an oval cross section, the flatter sides can breathe in and out in response to the pressure pulses. So they're more likely to behave as a big speaker below your cab, and you'll hear it while cruising in the e-way.

My suggestion is to get something cylindrical, to minimize resonance.

Resonance can ruin your cool ride. Be careful.

2001Silverado2500HD · August 6, 2005

Flowmaster or Magnaflow? Called a shop guy said same price. Said Flowmaster more for the Loudness but magnaflow gives more performance. What do u guys recomend?

Z71-cummins · August 6, 2005

Just get a Flowmaster. Why buy a performance muffler if u dont want the sound mike. They both give teh same performance even though each say they are better than the other. If you want a cool, loud, nice soundin ride get a Flow JMO. BMO for your truck would be the dual exhaust with the split exhaust (the kind not comin thraight back but at the angel. Those look and sound a whole lot niceer than straight back IMO.)

mmmikkke · August 6, 2005

...Why buy a performance muffler if u dont want the sound mike....

<{POST_SNAPBACK}>

Sound is fine if it comes out the tailpipe(s). Sound under the cab is what I don't want. Just my 2 cents worth though.

You want the sound behind you. You already know you have a badass truck, the sound is for everybody else!

Haulin' 8.1 · August 7, 2005

Those 50's will drone, mine do. Now I know that there are better Flowmasters to use, like 70 and 80 series Big Block series flowmasters, all the flow without the loudness. As soon as I can I'll be replacing the Flowmasters in my sig with something less obnoxious.

Vernon

By the way the guys at my muffler shop had never heard of them, I found them in thier catalogs and said, "What about these, they say they are barely louder than stock?" He looks it over and says "Huuh, I never noticed those." Me: "How much to change these out for those." he calls warehouse, says "about another $300." I think, thanks a lot dueffess, anything else I can educate you on about your product line.

Z71-cummins · August 7, 2005

Well mike im sorry i dont see eye to eye cause i dont mind my interior noise as you do. But i liek the sound all around me in the back in the cab everywhere. Thats why im probably goin to straight pipes within the year. Cause i want everyoen to knw i have arrived. And you say the 70 series is loud in cab i have to disagree. Cause on highways you cant notice the sound not unless you suddenly accelerated. Sorry if to u mike if u didnt say that the flowmasters were loud on highway i was just statin my opinion.

mmmikkke · August 7, 2005

Well mike im sorry i dont see eye to eye cause i dont mind my interior noise as you do. But i liek the sound all around me in the back in the cab everywhere. Thats why im probably goin to straight pipes within the year. Cause i want everyoen to knw i have arrived. And you say the 70 series is loud in cab i have to disagree. Cause on highways you cant notice the sound not unless you suddenly accelerated. Sorry if to u mike if u didnt say that the flowmasters were loud on highway i was just statin my opinion.

<{POST_SNAPBACK}>

Go for it, Z. Everybody needs to find their own way in life. I was just sharing a lesson learned... maybe it doesn't apply.

SS Crew · August 8, 2005

Go with the FloPro 2503 muffler it's made for the 6.0 and the 8.1. You don't hear it in the cab, but outside it has a little growl. It took a couple thousand miles for it to "burn in" - when it was installed it was actually quieter than stock. You get absolutely no resonance. This is the perfect muffler if you want don't like noise in the cab. I haven't felt any seat-of-the-pants difference, but I have heard some dyno tests showed an increase of torque. If you do want more noise they have the 2504 muffler with 2 outlets - that should give you more noise.

FloPro

cokedrvrbjw · August 8, 2005

Go with the FloPro 2503 muffler it's made for the 6.0 and the 8.1. You don't hear it in the cab, but outside it has a little growl. It took a couple thousand miles for it to "burn in" - when it was installed it was actually quieter than stock. You get absolutely no resonance. This is the perfect muffler if you want don't like noise in the cab. I haven't felt any seat-of-the-pants difference, but I have heard some dyno tests showed an increase of torque. If you do want more noise they have the 2504 muffler with 2 outlets - that should give you more noise.

FloPro

<{POST_SNAPBACK}>

I have a 2503 never installed if youre interrested. 100+sh.

SandZilla · August 15, 2005

Anyone use any dynomax bullet mufflers? A friend of mine gave me a set that came off a 8.1L but I have never heard them, was wondering how they sound. Dont want to go to all the trouble of putting them on if they sound like crap.