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Exhaust | Gundo Hack + Martian Mod (Center Bypass)
On Wednesday I had the Gundo mod done to the side mufflers and also bypassed the center muffler. Originally I wanted the NHP x-pipe but it has been on backorder for a while, a friend who did the fabrication work suggested that we cut open the factory center muffler and seal the perforated pipes inside it. Since I wasn't going to have a use for the original center muffler after an x-pipe install I decided to give it a shot, if it did not sound good I would just wait for the NHP to become available or go with another option. After installing I was very pleased with the sound and decided to keep this as the center bypass, it sounds great!!! I also love the fact that from behind the exhaust appears stock aside from the tips and titanium paint, and everything fits just like factory!
Here are few photos of the modification and final result after high-temp paint:
Last edited by 911obsessed; Oct 17, 2018 at 08:21 AM.
Great project and great results. Love your determination to get everything just the way you want it. All in good taste too imo. Looks like you nailed the stance with the coilovers. Totally transformed the car. Can't tell from the side shot if you added spacers. Typically a must when you lower to pull it all together. Other than that I doubt you'll need any adjustments there. Also....interesting solution with the center muffler. As long as you're happy with the sound and not bothered by the weight of the stock muffler that'll save you a minimum of $700 which is the lowest price I've seen for a set of crossover pipes.
Sounds like a 911 nothing to drastic there, but aesthetically the stance is on point.
Thanks! I love the sound, it is quite loud in person.
Originally Posted by sandwedge
Great project and great results. Love your determination to get everything just the way you want it. All in good taste too imo. Looks like you nailed the stance with the coilovers. Totally transformed the car. Can't tell from the side shot if you added spacers. Typically a must when you lower to pull it all together. Other than that I doubt you'll need any adjustments there. Also....interesting solution with the center muffler. As long as you're happy with the sound and not bothered by the weight of the stock muffler that'll save you a minimum of $700 which is the lowest price I've seen for a set of crossover pipes.
Thank you! I haven't added spacers as I will be getting wheels with appropriate offset shortly. The center muffler turned out great, I was not expecting it to sound as good as it does. I guess it makes sense since it is just straight piped internally now, also it is not that heavy (I haven't weighed it, but ~10lbs more than a set of crossover pipes seems about right).
A friend has the PSE with Sharkwerks center bypass and my setup is significantly louder and throatier in comparison (seems like 20-30% louder). It is very throaty at low revs and howls up top, I am very pleased with the setup and will get a better video up soon (cold start, revs, more drive-by's, WOT acceleration, etc.)
Thanks! I love the sound, it is quite loud in person.
Thank you! I haven't added spacers as I will be getting wheels with appropriate offset shortly. The center muffler turned out great, I was not expecting it to sound as good as it does. I guess it makes sense since it is just straight piped internally now, also it is not that heavy (I haven't weighed it, but ~10lbs more than a set of crossover pipes seems about right).
A friend has the PSE with Sharkwerks center bypass and my setup is significantly louder and throatier in comparison (seems like 20-30% louder). It is very throaty at low revs and howls up top, I am very pleased with the setup and will get a better video up soon (cold start, revs, more drive-by's, WOT acceleration, etc.)
So all you did to the OEM center muffler was cutting it open, seal the perforated pipes and then closing it up again? Nothing removed? I've seen a profile of the innards of the center muffler which showed a lot of bends and 180 turns which looked restrictive. But if your modification works as good as you say it does, this could be the Gundo version of the center muffler.
So all you did to the OEM center muffler was cutting it open, seal the perforated pipes and then closing it up again? Nothing removed? I've seen a profile of the innards of the center muffler which showed a lot of bends and 180 turns which looked restrictive. But if your modification works as good as you say it does, this could be the Gundo version of the center muffler.
That's it! The inside is very simple: the inlet does a 180 turn and becomes the outlet, that's all. I will call it the "Martian Mod" as my friend's name is Marcin and that's his go to muffler mod on many cars. Here is a photo I found online of the center muffler cut open:
Last edited by 911obsessed; Oct 17, 2018 at 08:20 AM.
coilovers are on and preliminary ride height is set! I did the install at home with a second set of hands, it went relatively smooth and took about 6 hours to complete. I will wait for everything to settle, fine tune the ride height and then get the alignment done. The car drives amazing now, stays very flat in corners and the ride is great. Here is a photo before i get a chance to do a full photoshoot later this week:
I also love the fact that from behind the exhaust appears stock aside from the tips and titanium paint, and everything fits just like factory!
