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The final piece... Dundon gt3 muffler conversion

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Old 03-08-2019, 10:03 PM
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SGOGT4
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Default The final piece... Dundon gt3 muffler conversion

Just pulled the PSE off my GT4. Already have the Full Dundon set up (runners, headers, plenum, Tb, tune). Excited to get the last piece in place - Dundon catted GT3 conversion. Anyone do the install yet? Any pointers in terms of order of operations?





Last edited by SGOGT4; 03-10-2019 at 09:37 PM.
Old 03-08-2019, 10:14 PM
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Five12Free
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In for some tips (install, not exhaust)... I’m waiting for my catted conversion to get here too.
Old 03-08-2019, 10:22 PM
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Charliekay
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Here for more info. Which GT3 muffler are you running? Dundon Lifetime Quiet? Loud? or a OEM Muffler?
Old 03-09-2019, 01:59 AM
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SGOGT4
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OEM Steel
Old 03-09-2019, 01:13 PM
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G-forceGT4
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Please post some photos when you have all the system together. The quality of components looks top notch.
Old 03-09-2019, 08:20 PM
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SGOGT4
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Made some progress... muffler is hung and over axle pipes are on. Took some time to chase the threads on the muffler flanges so ran out of time before I could get the elbos on.



Old 03-09-2019, 09:18 PM
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Five12Free
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Very cool... but man those cats are small. No wonder they don’t take away much power. Hopefully mine shows up this week.
Old 03-09-2019, 11:00 PM
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Alan C.
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If the cats are metal monoliths they will have thinner walls than ceramic cats and will therefore light off faster and have less cross section. Plus, you dont have to worry about them melting in a rich fuel situation like a fouled plug.
Old 03-09-2019, 11:13 PM
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SGOGT4
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If anyone has any pointers in getting the elbows lined up I’d take them... guessing need to keep the muffler fairly loose in the straps and play with final placement
Old 03-09-2019, 11:24 PM
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johnsopa
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I tried the GT3 muffler only GT4. Too much drone for me at lower RPMs. I don't have a cat. Maybe catted will have less drone. When spooled up, the sound was nice though!

What you said about keeping the inserts loose on the muffler is absolutely correct. Tighten those last after the other connections are tightened.
Old 03-10-2019, 01:04 AM
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SGOGT4
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Got to tell you... all this talk of drone has me nervous about firing this up for the first time. Hopefully the cats help
Old 03-10-2019, 01:14 AM
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G-forceGT4
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I'm sure it's going to sound great. I'd recommend copper anti-seize on bolts b/c sure makes it easier if & when you take it apart later. I find it's easiest when connections are left very loose until they're all made, then sequentially tighten them up. Having that wiggle room so to speak really makes a big difference. Are those 100 or 200 cell cats?

Last edited by G-forceGT4; 03-10-2019 at 11:44 AM. Reason: grammar
Old 03-10-2019, 01:40 AM
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Charliekay
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Originally Posted by johnsopa
I tried the GT3 muffler only GT4. Too much drone for me at lower RPMs. I don't have a cat. Maybe catted will have less drone. When spooled up, the sound was nice though!

What you said about keeping the inserts loose on the muffler is absolutely correct. Tighten those last after the other connections are tightened.
Which GT3 muffler were you running? Dundon Lifetime, OEM Steel or OEM Titanium? Any other mods?
Old 03-10-2019, 01:37 PM
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ajw45
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Originally Posted by SGOGT4
Got to tell you... all this talk of drone has me nervous about firing this up for the first time. Hopefully the cats help
Cats should help a lot with the drone and steel GT3 exhaust should drone less than the RS titanium box. I was running no cats and RS center, drone was pretty intense but once you get past 3500rpm it sounds amazing.
Old 03-10-2019, 04:49 PM
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Five12Free
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Originally Posted by ajw45
Cats should help a lot with the drone and steel GT3 exhaust should drone less than the RS titanium box. I was running no cats and RS center, drone was pretty intense but once you get past 3500rpm it sounds amazing.
Maybe it’s just me, but I feel like the PSE drones with the valves open.

I went with a stock .1 GT3 muffler with Dundon race headers and catted GT3 conversion kit too. If it’s too loud, then I guess the Dundon quiet muffler is the next step.

either way, your car with the RS muffler sounded sick!


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