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Magnaflow Fail

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Old 09-22-12, 08:03 PM
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Wankel

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AR Magnaflow Fail

Well my Magnaflow made it about 6 months! It is on a 1984 GSL SE with a RB header and presilencer.

Was doing some brake work when I got finished I decided to make a video of my exhaust compared to my past set up. I played it back and it showed water boiling out of the side. I was like WTF! and took a closer look and seen the crack about a 1/4 of the way around the weld.

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Old 09-22-12, 08:06 PM
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premix, for f's sake

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Ghey do they have warranty against being weak sauce when exposed to "real" exhaust?
Old 09-22-12, 08:08 PM
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Originally Posted by Sgt.Stinkfist
Ghey do they have warranty against being weak sauce when exposed to "real" exhaust?
Not sure lol, I figure it getting soooo hot and and with all the rain we have had the past couple of weeks may have stressed it. You wouldn't think the weld would be that week!

If I dont run across another muffler, I make cut it open and fill it full of lava rock(like the race mufflers).

Last edited by XXXJ; 09-22-12 at 08:11 PM.
Old 09-22-12, 08:37 PM
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I actually own Rotaries

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I have a brand new RB rotor shaped muffler never used if your interested... its the big one with 3 inch
Old 09-22-12, 09:40 PM
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Originally Posted by 73rx313b
I have a brand new RB rotor shaped muffler never used if your interested... its the big one with 3 inch
Ill keep you in mind if I buy anything. How much are you wanting?
Old 09-22-12, 10:21 PM
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I actually own Rotaries

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i will take 100 plus shipping.... thats exactly what i paid for it from another forum member but i never used it
Old 09-22-12, 10:22 PM
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I actually own Rotaries

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just shoot me a PM if interested... i can email a pic if you want
Old 09-23-12, 04:56 AM
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Have RX-7, will restore


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most aftermarket mufflers just simply cannot take the heat of the rotary engine. i've seen worse muffler blowouts. this is one of the many reasons that i only use racing beat exhaust products if i'm going aftermarket. they are designed and built to take the heat. i've never seen one split.
Old 09-23-12, 07:52 AM
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That's also why RB uses mild steel and not stainless. Stainless cracks easily when exposed to the strange differential heat that an exhaust system has. Red or orange hot in the middle, ice-cold on the outside after you splash through a puddle....
Old 09-23-12, 09:50 AM
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Originally Posted by peejay
That's also why RB uses mild steel and not stainless. Stainless cracks easily when exposed to the strange differential heat that an exhaust system has. Red or orange hot in the middle, ice-cold on the outside after you splash through a puddle....
Not true, Racing Beat's universal mufflers are 304 stainless and also use it in their presilencers.
Old 09-23-12, 10:21 AM
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Lapping = Fapping

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They are also 18 gauge on the outside shell which is thinner than magnaflow's 16 gauge.
Old 09-23-12, 01:49 PM
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Originally Posted by XXXJ
Not true, Racing Beat's universal mufflers are 304 stainless and also use it in their presilencers.
Huh, that sucks.

My long primary system is made out of heavy wall mild steel. IIRC it's 1/8" tubing and 3/16" plates. It is very, very heavy. On the other hand, it's very, very quiet. Driving down the highway, I hear a faint purr that is mostly drowned out by diff and trans noise and the tires of nearby cars/trucks.

I don't know how old it is, I bought it from Paul Aber a while back, and I think he bought it in 2000 or 2002 or so.
Old 09-23-12, 11:09 PM
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peejay, RB recently changed the construction of their presilencers in the "Streetport" center section. While they used to be constructed of heavy materials ie 14 gauge shell and 3/8" end caps, they are now kind of a hotdog cherrybomb shape and are MUCH lighter. The whole center section is very light when you grab it at the middle to pick it up. Quite surprising considering it's still quiet.

The first time I fired it up, it blew lots of tiny fiberglass fibers everywhere. They broke in after a few miles. I suspect the new presilencers are sort of a glasspack/pot scrubber assembly that won't blow out due to the pot scrubber material protecting the fiberglass. This also has a quieting effect allowing the use of what I suspect is an 18 gauge 304 SS shell on such a loud engine.

As far as I know these new presilencers are only available in the streetport center section. But if you called them and asked, they might have a few kicking around that haven't been burned in yet.
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