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The final piece... Dundon gt3 muffler conversion

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The final piece... Dundon gt3 muffler conversion

 
Old 03-14-2019, 07:13 PM
  #31  
Charliekay
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Originally Posted by benben01 View Post
Maybe you guys's hearing is much sharper than mine.. The drone under 2k'ish is character for me and really is not that bad IMHO. Again, this is highly subjective. I am going to mod my TPC pipes to include 200 cell cats this coming week so I can be a little bit more environmentally friendly
You're using the TPC kit with which headers and which GT3 muffler?
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Old 03-14-2019, 08:32 PM
  #32  
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Originally Posted by Charliekay View Post
You're using the TPC kit with which headers and which GT3 muffler?
heís got Dundon race headers and a GT3RS titanium muffler.
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Old 03-14-2019, 08:39 PM
  #33  
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TPC conversion with Akra center can be heard here but drone/boom is tough to capture in vids:

Akra GT3 center in Post #19
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Old 03-15-2019, 03:23 PM
  #34  
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Originally Posted by ajw45 View Post
Are you talking about the akra gt4 muffler or the akra gt3 center? The akra gt4 exhaust seems drone free for me, have been wondering about the akra gt3 center on a gt4....
Originally Posted by Charliekay View Post
I think ajw45 is referring to the Akra GT4 exhaust rather than using the Akra GT3 muffler.
I'm referring to the Akra GT4 exhaust, not their GT3 muffler. Don't know what it was about the Akra GT4 exhaust, but after about 10 minutes of street driving my ears would ring for hours afterward. It was definitely higher pitched than the stock GT4 exhaust or the conversion kit with a GT3 muffler.
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Old 03-15-2019, 03:47 PM
  #35  
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Originally Posted by BillC3 View Post
I'm referring to the Akra GT4 exhaust, not their GT3 muffler. Don't know what it was about the Akra GT4 exhaust, but after about 10 minutes of street driving my ears would ring for hours afterward. It was definitely higher pitched than the stock GT4 exhaust or the conversion kit with a GT3 muffler.
Huh, strange. I have race headers with the Akra GT4 exhaust on and it sounds great, maybe deeper/less raspy than stock PSE and no drone for me... and I think the valves are stuck open
I'm going to go back to the GT3 exhaust, so much more aggressive, but the Akra has been so much more liveable I still don't know which one I'm going to keep.....
​​​​​​
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Old 03-15-2019, 08:27 PM
  #36  
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Originally Posted by ajw45 View Post
Huh, strange. I have race headers with the Akra GT4 exhaust on and it sounds great, maybe deeper/less raspy than stock PSE and no drone for me... and I think the valves are stuck open
I'm going to go back to the GT3 exhaust, so much more aggressive, but the Akra has been so much more liveable I still don't know which one I'm going to keep.....
​​​​​​
wonder what an Akrapovic GT3 exhaust would sound like... but Iím not paying 5k to find out!
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Old 03-15-2019, 09:44 PM
  #37  
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Weíre getting there! Managed to find an hour before dinner this evening. Definitely pay attention to how the mounting plate is assembled when it arrives. I took mine apart (thinking I knew better - wrong) and reassembled it backwards. If it doesnít have the right angle / orientation the muffler wonít line up to the elbows.







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Old 03-15-2019, 10:06 PM
  #38  
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Is there a post cat O2 sensor, or are they just both on the headers?

Nice pictures. Very informative. Thanks
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Old 03-15-2019, 11:30 PM
  #39  
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I had the tpc conversion cup style without valves with gt3 steel box with fabspeed race headers and the drone was unbearable between 2-3k. Iíve since switched to cargraphics long tube race headers and the drone is significantly less, enough to street the car now. Itís still there but doesnít give me migraines anymore.
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Old 03-16-2019, 12:34 AM
  #40  
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No O2 sensors past the cats... only the ones on the headers
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Old 03-16-2019, 02:16 AM
  #41  
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Any chance to post a dyno result after all the mods? I am sure a lot of ppl will be quite curious and not just result posted by dundon.

Is the car a lot faster and straight line acceleration comparable to 991.1 GT3?
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Old 03-16-2019, 08:08 PM
  #42  
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Well itís finally done! Getting the passenger side elbow In was a PITA. Ended up dropping he muffler and installing the elbows and the reinstalling the muffler and inserting the cats.
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Old 03-16-2019, 08:14 PM
  #43  
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Sound wise... there is a little boominess in the 2k-3k range but nothing too bad. Overall I really like the tone. Much deeper and throaty. Not a huge difference between flaps open or closed but around town and with the windows closed it is good to be able to shut the flap and tone down the interior volume a bit. The high shriek of the race headers once you hit 4K and above has been softened up a bit. Actually probably better now for a street car. Cracks and pops at throttle lift are a bit muted now. Crank it up though and it sounds great. Very Porsche sounding... almost like my old air cooled at full tilt.

Last edited by SGOGT4; 03-17-2019 at 10:53 AM.
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Old 03-16-2019, 08:15 PM
  #44  
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Awesome... but how does it sound???
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Old 03-16-2019, 08:21 PM
  #45  
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For only having taken it out for 30 minutes Iím pretty happy. Need get it out and do some data logs to make sure Jamie can check the final tune results. The one thing that isnít great is the tip alignment. Iím running the Sharkwerke 100mm tips now. They just fit with what I hopemosnsifficient clearance. Length wise I think they are good but the overall orientation of the muffler is that it has a slight pitch down to the front. As a result the tips dip down a bit. Or a huge amount but their overall length make it noticeable (at least for my OCD).
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