flowmaster 40s / magnaflow
03-24-2007, 02:21 AM
#1
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flowmaster 40s / magnaflow My GTO needs to make some noise and get noticed.. 
I am looking for HP gain, but I just want to change the mufflers.. I want to leave the tips stock.. Does any GTO owner have a sound clip of the 40's and the magnaflows? I wanted to pick them up tomorrow at jegs and hopefully have them put on, but I don't know what I want. Any opinions would be great.
I am looking for HP gain, but I just want to change the mufflers.. I want to leave the tips stock.. Does any GTO owner have a sound clip of the 40's and the magnaflows? I wanted to pick them up tomorrow at jegs and hopefully have them put on, but I don't know what I want. Any opinions would be great. 
03-24-2007, 10:32 AM
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You're not going to get much, if any, power gain out of mufflers. The stock mufflers just aren't that restrictive at stock power levels.
That being said, I have a set of Super 40's and Magnaflows welded to stock flanges and hangars so it's a quick 15 minute swap. I also have an h-pipe in place instead of the stock resonator.
The Super 40's are definitely louder at idle and have more of the chambered muffler resonance. The seem to quiet down a bit once moving, and then have a little pop on decel/shift. Wide open throttle sounds great, and volume isn't ridiculously loud.
The Magnaflows are quieter at idle, a bit louder under part throttle, and have a smoother sound at wide open throttle.
Neither seems to have a drone out on the highway at all.
My take would be this:
If you want more of a refined sound the Magnaflows are for you.
If you want a tad bit more of that muscle car sound, you might be happier with the Super 40's.
That being said, I have a set of Super 40's and Magnaflows welded to stock flanges and hangars so it's a quick 15 minute swap. I also have an h-pipe in place instead of the stock resonator.
The Super 40's are definitely louder at idle and have more of the chambered muffler resonance. The seem to quiet down a bit once moving, and then have a little pop on decel/shift. Wide open throttle sounds great, and volume isn't ridiculously loud.
The Magnaflows are quieter at idle, a bit louder under part throttle, and have a smoother sound at wide open throttle.
Neither seems to have a drone out on the highway at all.
My take would be this:
If you want more of a refined sound the Magnaflows are for you.
If you want a tad bit more of that muscle car sound, you might be happier with the Super 40's.
03-27-2007, 07:22 PM
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I love flows had them on my Z28 but they were at a realy bad angle so i took them off. My friend is putting them on his gto now since you guys have some room to play with on those cars.
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04-09-2007, 10:44 AM
#9
TECH Resident
here are a few clips of both catback systems. however they are both with LT's.
magnaflow
http://s51.photobucket.com/albums/f3...t=MOV02531.flv
flowmaster
http://www.youtube.com/watch?v=_ZCUa-bCBII
magnaflow
http://s51.photobucket.com/albums/f3...t=MOV02531.flv
flowmaster
http://www.youtube.com/watch?v=_ZCUa-bCBII
05-03-2007, 11:52 PM
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05-04-2007, 10:29 AM
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if you want sound, go with flows. Some people say its a hollow tin sound, I have heard them in person coupled with long tubes. I can see how one might say that but I thought it sounded pretty good.
Magnaflow, which I have sound excellent with long tubes. The cat back, before I did headers wasnt all that much louder until after 4k rpms. After 4k rpms it screamed.
Neither will give you much if at all perormance wise. cat backs and muffler swaps are about sound not performance. If you want more depth and sound, keep the stock cat back and get long tubes (if you arent in cali). The headers and dyno tune gave me a nice performance boost as well, now above 4k rpms its LOUD. Cruising and moderate throttle has no droning but not obnoxiously loud, it does turn some heads though.
Magnaflow, which I have sound excellent with long tubes. The cat back, before I did headers wasnt all that much louder until after 4k rpms. After 4k rpms it screamed.
Neither will give you much if at all perormance wise. cat backs and muffler swaps are about sound not performance. If you want more depth and sound, keep the stock cat back and get long tubes (if you arent in cali). The headers and dyno tune gave me a nice performance boost as well, now above 4k rpms its LOUD. Cruising and moderate throttle has no droning but not obnoxiously loud, it does turn some heads though.
05-27-2007, 08:43 PM
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Check out the new KOOKS QCR Mufflers. I just installed them on my GTO that had FlowMaster Orginal 40's on and all I can say is this setup with 1 7/8 LT and Resonator delete with H-pipe and KOOKS QCR Mufflers is insane.
http://www.kookscustomheaders.com/show.php?pid=520
http://www.kookscustomheaders.com/show.php?pid=520
Last edited by mdmike; 05-27-2007 at 08:48 PM.
05-28-2007, 12:18 AM
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i know it is a completely different car, but i have the flow 40's on a true dual setup, lt's w/ no cats, dumped before axle, and it sounded good with the old 305, very good with the stock 350, and now straight up nasty with the new motor (mild 355). it is a loud idle, and WOT SCREAMS. i love them for the sound, but i will be putting in cutouts since they are somewhat restrictive mufflers
