Exhaust Noise

Lgetz · September 21, 2017

Another vote for the Magnaflow 12909. Left resonator but removed flapper valve. Has a good deep sound and won't drone you to death on the highway.

tyler.frost92 · October 15, 2017

Another vote for the Magnaflow 12909. Left resonator but removed flapper valve. Has a good deep sound and won't drone you to death on the highway.

I was wondering a what a 12909 would be like with no resonator but leave the flapper [emoji848]

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GMC_SD_Ult_16 · October 16, 2017

I was wondering a what a 12909 would be like with no resonator but leave the flapper [emoji848]

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I tried it with my 6.2L and it wasn't bad but my flapper was making some weird rasping noise... I don't know if bad flapper or since other items like OEM muffler and resonator were removed it was more noticeable... I will say with flapper and resonator removed it felt like I freed up some restriction in the system combined with my AFE Cai and 12909. The truck was much more responsive and gets slightly better mileage now. The internal diameter of the pipe for the flapper is smaller than all other areas and seemed to me to be a bottle neck for the 3 to 3 1/2 inch exhaust pipe system of the 6.2L.

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mayfieldjeff · October 17, 2017

i have the AFE CAI as well on. its loud. i received my 12909 magnaflow. just trying to find the time to go get it installed.

tyler.frost92 · October 18, 2017

I'd like to hear some sound clips on the 12909

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wildlyfe200 · October 18, 2017

I tried it with my 6.2L and it wasn't bad but my flapper was making some weird rasping noise... I don't know if bad flapper or since other items like OEM muffler and resonator were removed it was more noticeable... I will say with flapper and resonator removed it felt like I freed up some restriction in the system combined with my AFE Cai and 12909. The truck was much more responsive and gets slightly better mileage now. The internal diameter of the pipe for the flapper is smaller than all other areas and seemed to me to be a bottle neck for the 3 to 3 1/2 inch exhaust pipe system of the 6.2L.

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I have the GM bolrla with the flapper on my 6.2. I have ARH 1 7/8 LT headers in front of the flapper. I also get a weird rapsy/humming noise from 2.5k to 3.5k RPM. From the extra flow it seems like the flapper is acting like a reed in an instrument. The flapper is tuned for everything to be stock in front of it. For me it's a trade off no V4 drone but raspy noise or V4 drone and no raspy noise with a flapper delete. I only hear the raspy noise when I really get on it for a short bit it really isn't that bad.

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drentlaw1 · October 20, 2017

On 10/18/2017 at 6:05 AM, wildlyfe200 said:

I have the GM bolrla with the flapper on my 6.2. I have ARH 1 7/8 LT headers in front of the flapper. I also get a weird rapsy/humming noise from 2.5k to 3.5k RPM. From the extra flow it seems like the flapper is acting like a reed in an instrument. The flapper is tuned for everything to be stock in front of it. For me it's a trade off no V4 drone but raspy noise or V4 drone and no raspy noise with a flapper delete. I only hear the raspy noise when I really get on it for a short bit it really isn't that bad.

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I don't think it's the flapper causing the rasp. I have Kooks 1 7/8 headers and catless y into a Corsa Sport exhaust (no flapper). It's installed on my 6.2 and I have bad rasp in the same rpm range as you. I'm thinking it's the no cats and headers causing it. I'm going to add a small muffler in addition to the Corsa sport and see if that helps.

Did you go catless or catted with your ARH?

wildlyfe200 · October 20, 2017

I don't think it's the flapper causing the rasp. I have Kooks 1 7/8 headers and catless y into a Corsa Sport exhaust (no flapper). It's installed on my 6.2 and I have bad rasp in the same rpm range as you. I'm thinking it's the no cats and headers causing it. I'm going to add a small muffler in addition to the Corsa sport and see if that helps.
Did you go catless or catted with your ARH?

I went with the hi flow cats. I have to try to wire the flapper open and see if that is the issue. It is not easy made a quick attempt and failed. The new ones are rounded the older ones are square where the spring is. I can deal with the sound it just would be nice not to hear it. I'm going to make a point this week to get that thing wired open and get an answer.

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drentlaw1 · October 20, 2017

7 minutes ago, wildlyfe200 said:

I went with the hi flow cats. I have to try to wire the flapper open and see if that is the issue. It is not easy made a quick attempt and failed. The new ones are rounded the older ones are square where the spring is. I can deal with the sound it just would be nice not to hear it. I'm going to make a point this week to get that thing wired open and get an answer.

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Yea I'm curious on if it fixes cures it for you. I've been meaning to get a video of mine but haven't had time and I can't find my GoPro suction cup mount.