unotaz

Great question and the answer will surprise you. The Speedster with the full Dundon set up (street header + loud muffler) is actually QUIETER than the R with only the street header + OEM titanium muffler.

The sound in the Speedster is more raspy and higher pitched, but quieter and more refined. The sound in the R, with only the street header, is louder, deeper and more raw. The R also spools up faster than the Speedster thanks to the SMFW.

This just shows you how different the tune and engine architecture is between the 991.1 GT3RS engine vs. the 991.3. Unfortunately, this also tells you that with the way things are going (emission and noise regulations), it's not going to get better going forward. Sure, newer engines will have more power and higher rev band, but it's going to get quieter and more refined as time goes on.

Holdens

Thanks! And yes, the answer surprised me.


I would have thought the loud muffler would have been, well, louder... Makes sense though after you explained it. And agree that the sound of these cars will continued to be neutered by emissions / sound requirements.

unotaz

I was surprised too when we fired up the R for the first time after the installation. My tech and I looked at each other and said “Man, is it me or does this sound louder than your Speedster set up??”

We were both expecting the R to sound quieter considering it had the OEM muffler, compared to the full set up in my Speedster. But that wasn’t the case. While I can’t comment on the Speedster on the before and after, since I installed the system on Day 1, I could tell you there was noticeable difference in my R. I ran my R for several thousand miles in the stock set up and immediately when I drove it after the install, I could notice the revs spooled up faster across the range. Mid-range pulls were noticeably more punchier.

I have to be honest here, I put in the Dundon system in both of my cars simply because I liked the sound. Having a few extra HP is just icing on the cake.

Soul Performance

If anyone is considering a side muffler bypass or center muffler bypass, please feel free to check our thread below that has a detailed breakdown of the exhaust flow paths on the various GT3 models. We cut the mufflers open so you can visualize and understand fully what's going on in there. You can also review the discussion/feedback from various owners

https://rennlist.com/forums/991-gt3-...explained.html

Best regards,
John Gaydos

Alan C.

John has some nice options.

gmgracing

Here’s a little video of the GMG Racing 991.2 GT3 RS with our GMG WC EVO Long-Tube Headers & Titanium Center Section Exhaust stretching its legs on a set of Pirelli Slicks at Willow Springs! Enjoy!

Alan C.

I've looked but I can't find any before and after dyno results on the GMG. Anyone have the results?

purcell21

I've read thousands of posts on RL and this is BY FAR the best AND FUNNIEST I have ever read. I just busted out laughing out loud and the kids all turned and looked at me wondering what's up. I have a feeling they will be repeating "dyno your *****" for the next month. Thanks for the laugh and truth. I just returned today from three days at VIR and that made this even more funny, and true, unfortunately.

mooty

^ thx. I try my best to entertain.

Robocop305

Does the 991.1 GT3 Fabspeed catback competition X-pipe fits a 997 GT3? Thanks.

msos

Just bought GT3T with Soul center exhaust and it sounds awesome!

Soul Performance

Thank you for your business and support! Any video clips so we can all hear it?

-Mike

David Carp

Originally Posted by mooty [img]images/buttons/viewpost.gif[/img]
i have stock exhaust.
i dont believe in dyno cars
car doesn't go fast by itself
you make it go fast
big ***** make car go fast
big exhaust no so much.
ymmv all depends on what kind of ***** you have. my are tungten

So Mooty

Isnt your physical condition painful during high g corners? Or do you have special bucket seats, kind of with a sub-bucket.

Tungsten is 1.7 times denser than lead. And just as a point of interest about the same density as plutonium.

3-Pedals

Nice one

Fabspeed Motorsport

2020 got you thinking more about your car than your vacation to Disneyworld?! Us too! If you are looking for a simple solution for your GT3/GT3RS dismal exhaust note, I would absolutely suggest sheading some SERIOUS pounds and bypass your side mufflers with a set of Fabspeed Motorsport GT3 Side muffler bypass pipes! Completely bolt on, no lights, and plugs right into factory PSE lines! Due to extremely high demand, we have a few sets in stock ready to ship! Take a look and listen below to some of the basic product details and feel free to PM me or reach out directly for forum pricing!

• Fits all Porsche 991 GT3 / GT3 RS vehicles (2014-2016)
• Highest quality Helical valves
• Includes O2 bungs for factory like functionality when paired with Fabspeed Long Tube Competition Headers
• Saves 34 lbs from the rear of the vehicle
• Replicates aggressive CUP car sound for the street
• 14-16ga T304 Stainless Steel construction
• Simple bolt-on installation
• All Fabspeed performance products are backed by the Fabspeed Lifetime Warranty
  
  
  
  
  HELICAL VALVES
  
  We chose to use Helical Valves on our 991 GT3 / GT3 RS track exhaust systems for their unprecedented quality - which have been proven by many OEM manufacturers such as McLaren, Ferrari, Lamborghini, and many more. Helical valves are an integral part of our Side Muffler Bypass pipes, opening and closing with precision to control the gas flow and optimizing engine back-pressure for improved performance. Helical’s extensive experience in high-volume OEM automotive applications has led to standard features such as an extremely durable pneumatic actuator, precision flat sealing faces inside the valve, stiffening ribs and high-temperature bearings at both ends of the butterfly