Exhaust mod - clarification of Gundo and Fister

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Water Hound
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Exhaust mod - clarification of Gundo and Fister

Post by Water Hound » Sun May 27, 2018 3:22 pm

A lot of confusion swirls around the names of two common exhaust mods. The "Gundo Hack" and "Fister mod" are two completely different mods which result in different exhaust notes.

The Gundo PSE style mod
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Gundo PSE style mod
This is a Porsche Sport Exhaust (PSE) style exhaust without the inline solenoid switch enabling it to be opened or closed. With a Gundo you're open all the time - perfect! This mod is a partial muffler bypass. All gases pass through at least a portion of the muffler. Some of the exhaust takes a shorter trip and only flows through the first resonant chamber of the muffler then goes straight to the output pipe. To do this mod you open up the capped exhaust port in the muffler and connect it to the output pipe of the muffler with a stainless tube. The larger diameter the tube, the deeper and richer the exhaust note. My 2004 cabriolet has the Gundo hack with a 2" pipe. Because all exhaust passes through at least a portion of the muffler the sharper bark of the Fister mod isn't present. Glorious sound, no drone and amazing under full throttle.


Second, the Fister mod
image.jpeg
Fister mod
Whereas the Gundo runs all exhaust through at least a portion of the muffler, the Fister mod is a true muffler bypass for a portion of the exhaust The input and outflow pipes are joined with a tube directly. Results are a bit louder, raspier and there is a bit more of a sharp bark to the exhaust note without being too loud. The larger the diameter of the pipe used, the deeper and throatier the exhaust note. This is the mod that will find a home on my C4S in the near future and is likely the perfect option for a coupe. The Fister mod is done professionally by Darren Fister and you can see his work at fdmotorsports.net. While many people do their own hack for a Fister mod, FD offers a guaranteed job with a great selection of finishes.

To sum up, these are two excellent exhaust modifications. While they don't offer real horsepower gains, they will definitely sound at least 50 hp faster. As a warning, your fuel economy will suffer because you won't be able to stop yourself from putting your right foot down a lot more aggressively. Enjoy!
2004 C2 Cabriolet, Midnight Blue/Savannah Beige
2004 C4S Coupe, Atlas Grey/Black

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5chn3ll
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Re: Exhaust mod - clarification of Gundo and Fister

Post by 5chn3ll » Wed May 30, 2018 9:04 am

Nicely put.

TL;DR: Do the Fister, not the Gundo

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flatsix
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Re: Exhaust mod - clarification of Gundo and Fister

Post by flatsix » Fri Jun 08, 2018 9:36 pm

20160204_161944.jpg
I could not decide so I did both. it's not as deep sounding as I thought it would be but that could be due to the headers. It is a huge improvement in sound over the un modified stock exhaust.
2001 Carrera 4 6spd

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Water Hound
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Re: Exhaust mod - clarification of Gundo and Fister

Post by Water Hound » Thu Jun 14, 2018 7:26 pm

flatsix wrote:
Fri Jun 08, 2018 9:36 pm
20160204_161944.jpg

I could not decide so I did both. it's not as deep sounding as I thought it would be but that could be due to the headers. It is a huge improvement in sound over the un modified stock exhaust.
Let's call it the flatsix spaghetti mod! Quite a piece of modernist sculpture there.
2004 C2 Cabriolet, Midnight Blue/Savannah Beige
2004 C4S Coupe, Atlas Grey/Black

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