exhaust question for 2500 HD 8.1liter

1badrock · April 24, 2006

I want my truck to sound like it should haha....I dont know if i want to get duals or just a aftermarket muffler and keep the stock tail pipe. Is flowmaster better than magnaflow or are they both good. I dont want anything to obnoxiously loud just a nice clean big block tone. Would it be a better idea to get duals out the back? I imagine the 8.1 can sound real nice with a nice muffler.

Thanks

rich

ZZebes · April 25, 2006

Magnaflow

DiegoYJ · April 25, 2006

I went with a single Magnaflow muffler. I kept the stock tail pipe since it's already pretty big

The sound is great, hardly noticable over stock at idle and a nice deep tone when accelerating but not too overbearing at cruising speeds

1badrock · April 26, 2006

I went with a single Magnaflow muffler. I kept the stock tail pipe since it's already pretty big
The sound is great, hardly noticable over stock at idle and a nice deep tone when accelerating but not too overbearing at cruising speeds

<{POST_SNAPBACK}>

did you buy the magnaflow with the dual 4'' in and out???

Rich

dewfpo · April 26, 2006

I think he means dual 3" In/Out?

DEWFPO

soccermom · April 26, 2006

FYI, I just put a 3" in/out Magnaflow #12599 on my 6.0, keeping the stock tail pipe. It resonate like a mofo at light throttle b/t 1500-2000rpm. Sounds great under load and is silent at cruising speeds.

My buddy has the same truck/muffler with dual tail pipes. Same great sound and zero resonance. I'm adding dual tail pipes this week.

It seems that the dual 3" outlets going immediately into the factory Y pipe is the cause of the resonance on my set-up, which has the same OEM exhaust as the 8.1

1badrock · April 26, 2006

yeah whoops i did mean 3''

what do you guys think if you just end the exhaust right behind the muffler with like 2 elbows pointin down....?? just a thought something different

i'll prolly end up with the duals out the back.

thanks

dick

ZZebes · April 26, 2006

Turndowns will be louder but will have more resonance

Cheekster96 · April 26, 2006

Hey gang..can i ask a dumb question...

What exactly is resonance? Is it a rattling, vibration coming from the exhaust? I had a 03 Sierra 4x4 that the dealer said i had a resonance coming from the exhaust and wanted to put welds on the muffler to correct it. Turned out that the universal joint in front of the transfer case was bad.

Anyhoo, can some one go more into detail about resonance?

Thanks.

Lee

dewfpo · April 26, 2006

Anyhoo, can some one go more into detail about resonance?

Thanks.

Lee

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Lee,

The exhaust system makes noise and vibration (sound pulses) that varies throughtout the rpm range, and those sound pulses also vary based on load.

The cab of your truck is essential a very large metal drum that you sit in.

Under certain conditions the sound pulses (vibrations) from your exhaust system cause the cab to vibrate into the sound range that you can hear. The 'noise' you hear is the cab 'resonating' in tune with the exhaust system. Changing the rpm or load will change or eliminate the resonance (at least what you hear). OE manufacturers work hard to keep the exhaust pulse frequencies generated by the OE exhaust sytem from getting the cab to resonate winthin the human hearing range. The cab will always resonate to some degree. You just don't often hear it.

Resonance can be deafening and downright annoying. Especially if it happens within your cruising rpm range.

Sound insulation within the cab help to 'dampen' those sound pulse vibrations.

I hope this makes sense.

DEWFPO

Cheekster96 · April 27, 2006

Thanks DEWFPO. I understand it now.

Is it a safe assumption that if you get a more aggressive (louder) muffler, you will have more resonance?

I will be looking at aftermarket mufflers in the near future, have heard good things about Magnaflow and Borla.

Lee

dewfpo · April 27, 2006

It really depends on the muffler and exhaust system design. All things being equal and if your just changing the muffler to a louder design, you will change the resonance characteristics of the truck. Louder equals larger sound pulses, the cab will respond. Whether the resonance [after] is now in your hearing (frequency range) or not depends on the design of the muffler. There's no straight answer other than ........ yes, there's possibly a good chance it is. I suggest finding somewone who has installed exactly what you want and ask them questions so you won't be dissappointed.

DEWFPO

1badrock · April 27, 2006

local exhaust shop told me it would cost me $2000.00 to chop my exhuast off n put duals on with an accellerator muffler. Is it me or is this insane. Im gonna do something my self most definitely now.

Dick

dewfpo · April 27, 2006

local exhaust shop told me it would cost me $2000.00 to chop my exhuast off n put duals on with an accellerator muffler. Is it me or is this insane. Im gonna do something my self most definitely now.

Dick

<{POST_SNAPBACK}>

I hope you laughed in their face.........if they can get it, good for them.

DEWFPO