My friend had a pair of muffler bypasses from his old car, I had never heard them installed but he said they sounded great on his car.
I have PSE, but wanted something a little louder and deeper sounding. So I removed the rear bumper and the mufflers and installed the bypass pipes.

Well they sounded good at idle, and great from outside the car, but there is a terrible drone from 2-3500 rpm, enough to give you a headache and give you nausea after a 10 min drive. I liked the sound and the weight savings but could not live with the drone. I found some inserts that are made to reduce drone and took a chance that it would work.

Well they needed a little bit of work to make them fit since the inside diameter of the pipes are not exactly 2 1/4 inch and the inserts needed a little grinding. But they did reduce 99% of the drone and reduced the volume inside the car. Definitely an option if you want something louder than most aftermarket exhaust options. Unfortunately I need new tips since my PSE tips will not fit on these pipes.

 

Karl B, i live in Bay Shore also and i would love to meet and hear your car someday. I have been debating whether to do a muffler bypass or a gundo/fister mod for some time now.

 

I have the car chemistry baffles as well. I still have some drone but it isn't the nausea inducing type. I have had the baffles since day one so I don't know what it would sound like without.

 

Juank my friends and I go to Captree every Sunday, you can catch me there.

 

What time u guys go to captree..I also live in manhassett

 

We usually are there between 8 and 10.

 

Karl,


My inserts only have 2 disk instead of three like yours. I think that's why I still have some drone. I am thinking about buying the same inserts as your vs the one with 4 disk (even more reduction of sound). According to the reviews on the 4 disk insert, it eliminates any drone. Do you feel the drone with the 3 disk insert is tolerable? You mention that's it is 99% reduced.


Also my inserts were easy on and easy off without modification. I'm not sure what size mine are because they came with the pipes. Do you think the 2" as opposed to the 2"1/4 would work?

 

Fwiw, I have had my gundo hack for about 3-4 months now and don't notice any drone, although comparatively my other car is so loud I need to wear earplugs even at idle haha

 

The PSE pipes inside diameter are not 2 1/2 inch, I also purchased the 2 inch inserts to see which fit the best but they were way too loose. I did have to do some considerable grinding to make them fit, I also welded the tube adapter with the hole on to the tube. The instructions say you can use the solid adapter to reduce the sound more or both together.

I would say that it's as loud as my friends GT3 with the center muffler delete, I still have the stock cats, which from my reading are quite restrictive. Any one with 200 cell cats would most likely need some type of muffler.

I am actually surprised that it sounds this good without mufflers, it's not a daily driver so that may be a factor for some, I might not even keep it if I had to commute with the car. I think the main advantage is the weight savings, the PSE mufflers must be 70 pounds.

I will have to see after I DE the car, I am sure the trip to Watkins Glen could become tiresome, but that's why they make ear plugs.

 

Thanks that helps. I bought one 2.25" 3 disk insert to see how that fits and sounds. Then based on your report, i think i will need the 2" 4 disk insert. (I commute to work everyday). Loud isn't the problem though, it's the drone that is starting to bother me. I've had them on for a couple months. I tried 200 cell cat with gundo and while the drone was gone, it wasn't loud enough.

 

nvm, I took my pipes apart just now to measure the CC inserts. They are 2.25"

I'll try the three disks and if there is still some annoying drone, I will get the 4 disk insert

 

I used the open plug, you could always use both the open plug on one end and the closed one on the other.

 

Fister mod no drone whatsoever and I love the sound especially when accelerating!:-)

 

Funny how people keep mentioning gundo/fister on this thread. People who use muffler bypass do so because gundo/fister/pse aren't loud enough. I have gundos sitting in my garage - They're not on the car for a good reason.

 

Guy at Porsche Palooza had a .2 GT3 RS with full bypass...sounded GREAT! I did fail to ask about drone in the cabin. He did trailer there so maybe it's that annoying?

Anyway, I have the PSE and Fabspeed X pipe...completely different sound than Fister. More high pitched, ferrari (for lack of a better term) sound. My buddy has the Fister and Sharkwerks x pipe and is a much lower, hot rod sound. Mine is plenty loud under load, just howls. I've got a lift and easy access to swap some things out and have been contemplating the full bypass for ****s and grins. Sounds like I may be chasing something not yet figured out yet? I wonder if I added 200 cell cats/headers to my current setup or just straight headers (we have no inspections here) if that would do more without the drone?