There seem to be a few ways to "HACK" the 996 mufflers..connecting the inlet and outlet pipes with a short "connector", opening what appears to be a closed pipe fitting at the other end of the muffler, and making a pipe connecting to the exhaust side of the muffler, doing both or actually opening the muffler itself (like Fister) and modifying it...(Or all 3) ???
I'm confused as to what to have done....I don't want LOUD, just a bit more when accelerating..

 

I like the Fister videos I've heard.

 

I'm going to have a local shop do the Gundo in a couple of weeks. Stainless tubing. I'll try and post some before and after sound clips. One question I have that I don't think I got a clear answer on when reading through hundreds of posts on various forums, was the increased heat in the engine bay. Have those of you that have done the Fister/Gundo really experienced a noticeable increase in heat?

Kyle

 

Shouldn't the exhaust be cooler? You are bypassing some of the muffler which traps the heat. The hot gases are exiting the exhaust quicker which should lower the temps.

 

Good thinking////

 

The mufflers provide some insulation and the exhaust gas temp would be lower on the tube exiting the exhaust than the temp going in. Bypassing the muffler, the bypass tube would have more radiant heat coming off as more hot exhaust is bypassing the muffler.

You know, after spending so much time reading about these mods, I dreamt about mufflers all night last night. Woke up EXHAUSTED.

 

The inlet/outlet by pass (1.75” stainless) created by Fister appears to be the best way to go. Not too loud.

Doing mine soon and the posts indicate the Gundo or PSE style is quieter and perhaps not sufficiently louder for the effort.

 

I did the Gundo hack a couple months ago with 1 1/2" tubing. I was going to go with the 2" like I've read in the forum, but my muffler guy said it wouldn't be easy to weld up to the existing 2" pipe (not enough to work with I guess when trying to get a clean weld to pipe). Regardless, I love it. It is not overboard like some of the rice rockets with the coffee cans, but throaty when I get on it and quiet when I keep the rpms down. Puts a frickin smile on my face when I go above 4k! I don't need anything else to make me happier with the little I spent. When the system is worn out, then I'll look at a complete exhaust system mod, probably with Dundon. Their work makes me drool, but you gotta have the money for that one.

 

X2 on Dundon, there headers alone look amazing!

 

Are these modifications on top of factory sports exhaust or do they mimic factory SE? Please help the unknowing, thanks. I have factory SE and love the sound, but I have nothing to compare it with mod wise.

 

The Gundo Hack is on factory( stock exhaust system) mufflers. Check youtube "gundo hack 996"

 

There's a few threads on this. I've done both ways ( Gundo, then Fister). I much prefer the fister. The gundo (PSE Style) was barely any louder than stock. I paired both with my catless x pipe. You can compare the differences between the two in the videos below:
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"Gundo" muffler with x pipe

"Fister: muffler with x pipe

 

I went with the Fister and love the sound.

 

Viper....I thought that the GUNDO was a pipe welded to connect the inlet and outlet , like the top picture, and the Fister was all internal??

 

Nice work Viper!