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Discussion Starter #1
Can somebody please explain to me the bascis of high flow cats?

I bought a 300C 5.7 with a magnaflow exhaust already installed. Im guessing from the pictures of that set up is that there is some sort of resonator in the middle before the pipes seperate into two? Can somebody explain to me what this piece is and what its job is? Also, do the high flow cats take the place of my current cats? Does the standard magnaflow exhaust come with these high flow cats and is that what that mystery piece is?

Lastly, how much should I spend on high flow cats and will they produce any gains without adding headers?
 

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Can somebody please explain to me the bascis of high flow cats? The Magnaflow web page explains it pretty well. http://www.magnaflow.com/02product/shopdisplayproducts.asp?SID=4Chrysler&zone=American&id=236&cat=300C Go to the FAQ section.

I bought a 300C 5.7 with a magnaflow exhaust already installed. Im guessing from the pictures of that set up is that there is some sort of resonator in the middle before the pipes seperate into two? Can somebody explain to me what this piece is and what its job is? Also, do the high flow cats take the place of my current cats? (Yes.) Does the standard magnaflow exhaust come with these high flow cats and is that what that mystery piece is?(No)(The cats are sold seperately, so the system on your car could be either.)

Lastly, how much should I spend on high flow cats and will they produce any gains without adding headers?(They can add up to 10 hp.)
 

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Magnaflow cats replace the original cats they come with a 3" pipes vs 2.75" on the SRTs & they are high flow, they made a differance for me, 1 of my best mods .
 

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Discussion Starter #4
Why cant I just cut out the cats altogetehr rather than getting high flow cats? I am in Texas and they dont check for emissions or even look under my car during the yearly inspection.
 

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Why cant I just cut out the cats altogetehr rather than getting high flow cats? I am in Texas and they dont check for emissions or even look under my car during the yearly inspection.
As someone who's been both with high flow cats and catless I can tell you two things for certain.

1. No cats will leave your exhaust tips dirty within 15 minutes of driving just after a wash. If your tips are stainless steel, the filth is more noticeable and and difficult to clean.

2. No cats will increase the decibal level both in and outside of the car. My drone was noticeably reduced with the cats on.

To each his own. I ran for about two years catless. I loved the sound - what that really means is, I loved the attention my car got. Finally, I put the cats on because I thought I was going to sell the car. It turns out that putting the high flow cats back on was one of my most appreciated mods. Cleaner exhaust tips, less ear damage.

Oh, and here's the kicker with dyno numbers to prove it. Putting the high flow cats back on resulted in *NO* hp/tq loss whatsoever. Period. Not even 1-2 hp. Nothing. That's how good the new HF cats are. That was the kicker for me. There was no good reason for me to keep the cats off, and I am sure the environment would be a ltitle more pleased as well :) I'll never go catless again.

Just my $.02
 

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As someone who's been both with high flow cats and catless I can tell you two things for certain.

1. No cats will leave your exhaust tips dirty within 15 minutes of driving just after a wash. If your tips are stainless steel, the filth is more noticeable and and difficult to clean.

2. No cats will increase the decibal level both in and outside of the car. My drone was noticeably reduced with the cats on.

To each his own. I ran for about two years catless. I loved the sound - what that really means is, I loved the attention my car got. Finally, I put the cats on because I thought I was going to sell the car. It turns out that putting the high flow cats back on was one of my most appreciated mods. Cleaner exhaust tips, less ear damage.

Oh, and here's the kicker with dyno numbers to prove it. Putting the high flow cats back on resulted in *NO* hp/tq loss whatsoever. Period. Not even 1-2 hp. Nothing. That's how good the new HF cats are. That was the kicker for me. There was no good reason for me to keep the cats off, and I am sure the environment would be a ltitle more pleased as well :) I'll never go catless again.

Just my $.02
+1
 

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Discussion Starter #7
Thanks for your help racy. If I have the magnaflow 5.7, should I just get the magnaflow high flow cats as well? Will the HF cats alter the exhaust, note and if so, how?

thanks
 

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Thanks for your help racy. If I have the magnaflow 5.7, should I just get the magnaflow high flow cats as well? Will the HF cats alter the exhaust, note and if so, how?

thanks
I can't answer your question about the specific product, as I don't know anything about Magnaflow. However, the cats will modify the sound, but not anywhere near like having a muffler or resonator.

Cat's will basically tone down the rasp. Volume is slightly dropped. But again, if you are expecting the cats to have an effect of a muffler or similar device, you'll be let down. Your exhaust note will be nearly identical, only a little more mild. Many people wouldn't even notice the difference. Only engine geeks will notice.
 

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Discussion Starter #9
Well right now I have stock cats, an X pipe resonator that came with the magnaflow exhaust and a muffler on each pipe near the tailpipes. If I swapped out to HF cats, would I leav the resonator or remove it?
 

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Anybody? ...and anybody know an about price for the HF cats?
Not sure what the current question is but the x-pipes are a fielder choice IMO if they are the same diameter. They knock down harmonics but collide flow. The high flow cats do change the tone but more the volume and increase the power. The stock resonator restricts air flow but cut down the volume quite a bit. My high flow cats ran about $550.
 

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I thought the HF cats brought about a significantly louder and deeper tone than the factory exhaust? I'm not interested in an entire exhaust, but I am interested in the HF cats. Are there any sound clips here of anyone with HF cats only? (specifically on the SRT if possible). I wonder about combining the cats with the BB resonator delete...
 

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IMO just replacing the cats only and leaving everything else all stock is not work the the time and money. You will pick up very little power and it will sound nearly the same as it does now. I would either leave it all stock or replace the cats and instal a nice cat back exhaust like Magnaflow or Corsa etc.

Just my $0.02 :)
 

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Anybody? ...and anybody know an about price for the HF cats?

Just picked up a set of JBA Hi-Flows from HHP for $479 shipped. Installing this wednesday with a Corsa Catback. Getting a pre and post Dyno done also, so I will post the results.
 
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