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The final piece... Dundon gt3 muffler conversion

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Old 03-16-2019, 08:22 PM
  #46  
SGOGT4
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Originally Posted by Five12Free
Awesome... but how does it sound???
you must of responded just as I was typing the sound recap in the post above you!
Old 03-16-2019, 08:24 PM
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Various view of the tips...








Old 03-16-2019, 09:19 PM
  #48  
Five12Free
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Originally Posted by SGOGT4
For only having taken it out for 30 minutes I’m 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 isn’t great is the tip alignment. I’m 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).
great to hear it sounds good... bummer about the tips. Is there any adjustability? Maybe the straps?

Originally Posted by SGOGT4


you must of responded just as I was typing the sound recap in the post above you!
I’m sneaky!
Old 03-16-2019, 10:26 PM
  #49  
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Tips are pointed down a bit, the length of them doesn't help. We'll get a set together that is perfect for you Rob! If you can measure the amount from the base of the muffler and how far down the ones you have now are sitting would be ideal. I'll bet 991.2 GT3 tips are perfect (they were on our car).

The muffler bracket isn't on as intended, but I know adjusting these early systems is a bear, now that we have production jigs going, the next batch will be way easier to install... And I really don't want you to have to go mess with it endlessly under the car!

Tips are on us for being an early adopter
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Old 03-16-2019, 10:51 PM
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Nice job Rob! I had a similar issue with my tips on the TPC kit. When the pipes and muffler were fitted and bolted up I went back and adjusted the angle by playing with the muffler straps to position the muffler as high up as possible and moving the tips up as far as the mounting points would allow.
Old 03-17-2019, 12:07 AM
  #51  
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Originally Posted by Jamie@dundonmotorsports
Tips are pointed down a bit, the length of them doesn't help. We'll get a set together that is perfect for you Rob! If you can measure the amount from the base of the muffler and how far down the ones you have now are sitting would be ideal. I'll bet 991.2 GT3 tips are perfect (they were on our car).

The muffler bracket isn't on as intended, but I know adjusting these early systems is a bear, now that we have production jigs going, the next batch will be way easier to install... And I really don't want you to have to go mess with it endlessly under the car!

Tips are on us for being an early adopter
Jamie - you guys are the best! Looks like 8” from base to the longest point of the slash cut




I am curious though about where I went wrong on the mount. If looking from the rear of the car at the transmission, the upper tabs are on the outside of the mounting plate and the lower tab is on the inside (transmission side of the plate). Seemed like that was the only orientation that would sync up the elbows to the muffler and cats
Old 03-17-2019, 06:45 AM
  #52  
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Originally Posted by SGOGT4
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 schreik 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.
2k-3k the drone sounds about right, there but not too bad. I find when taking off slowly and under 2000rpm it is really bad. How you find it under 2000rpm? The cats might make the difference.
Old 03-17-2019, 10:55 AM
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I didn’t notice anything particularly unusual below 2k....
Old 03-17-2019, 12:06 PM
  #54  
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Originally Posted by ajw45
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.....
​​​​​​
Maybe that's the difference -- I'm still running the stock cats/headers.
Old 03-17-2019, 05:49 PM
  #55  
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Originally Posted by SGOGT4
I didn’t notice anything particularly unusual below 2k....
I see you are in the Bay Area. Do you not worry about the new CA law? ($1000 minimum fine for modified exhaust if deemed too loud)
Old 03-17-2019, 05:59 PM
  #56  
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No I don’t. How would a cop ever know if my exhaust isn’t stock? Cat? Sure officer its right there. Muffler.... here is the Porsche P/N. Also I make it a point to not be blasting through town. My car is no louder than the F-cars and Mclarens I see running around. My wife’s family is all in LE. Will have to check with them on the practical application on this absurd tree hugger law though....
Old 03-17-2019, 09:04 PM
  #57  
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Originally Posted by SGOGT4
No I don’t. How would a cop ever know if my exhaust isn’t stock? Cat? Sure officer its right there. Muffler.... here is the Porsche P/N. Also I make it a point to not be blasting through town. My car is no louder than the F-cars and Mclarens I see running around. My wife’s family is all in LE. Will have to check with them on the practical application on this absurd tree hugger law though....
Agreed on it not being excessive loud, and an idiotic law. However, my understanding is that when enforced, they can F%&$ with you, and you are then required to take your car to a referee, where it will not pass with anything but stock exhaust.
I could care less about the $1000 fine, but would hate to go through the hassle taking the car to a referee, and then swapping it all back.

Last edited by GoKart Mozart; 03-17-2019 at 10:33 PM.
Old 03-18-2019, 08:18 AM
  #58  
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I was able to play a bit with tip angle by rotating the muffler ..try that. But be careful not to get too close to the bumper, these tips are pretty big (diameter) and will radiate heat into the black plastic surrounding them...mine doesn't look that great at many track days but it's a section that can be swap and you can't see it.
Old 03-18-2019, 12:22 PM
  #59  
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Originally Posted by SGOGT4
No I don’t. How would a cop ever know if my exhaust isn’t stock? Cat? Sure officer its right there. Muffler.... here is the Porsche P/N. Also I make it a point to not be blasting through town. My car is no louder than the F-cars and Mclarens I see running around. My wife’s family is all in LE. Will have to check with them on the practical application on this absurd tree hugger law though....
^^
I agree, & if we have high flow exhausts/headers on cars, a guy is just asking for it by blasting through town. I see these dipsticks driving bikes & cars going through school zones, then just gunning it for a loud sound blast. IMHO that's why they legislate & apply these laws. Being discreet & respectful of others goes a long way. The same goes for LE, these guys have a tough job & deal with a lot of riff raff.
Old 03-19-2019, 08:29 PM
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Swapped out the Sharkwerkes for stock 991.1 tips. Too short but look way better as an interim fix


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