Wait are you joking?!? I had cat bypass pipes on my FVD exhaust, it was very quiet!! My straight pipes whihc are cat/muffler bypass, are no joke 80x louder

 

I've been running FabSpeed cat bypass pipes for almost a year. The CEL light has not been triggered on my car. They are not loud at all when used with stock mufflers and stock headers. By the way, the GT3 Cup uses the same headers as the street GT3, so there is nothing wrong with these headers.

The MaxFlo mufflers plus stock cats and headers were way louder. The muffler bypass pipes plus stock cats and headers were the loudest ever on my car, to the point of having to dismount them after a short drive (ear pain).

From 1 to 10, 10 being the loudest:

3) Stock GT3 mufflers, cats, headers.
4) Stock GT3 mufflers, stock header, cat bypass pipes
5) PSE mufflers, stock headers, stock cats
6) stock GT3 headers, stock cats, MaxFlo mufflers
9) stock GT3 headers, stock cats, muffler bypass pipes.

I have not tried cat bypass pipes and muffler bypass pipes combined, but that must be as loud as the GT3 RSR.

 

Exactly what i thought

 

muffler bypass pipes are louder than catbypass pipes if you do one and not the other. I guarentee that!

 

you can't compare turbos to NA exhaust systems. totally different animal. i'd stay out of this one porsche newbie


the cats on NA cars do an incredible amount of noise suppression. we have four of them and they are terribly restrictive.

 

do you own,or should i say does your "family" own a 996? uhhh...no. i've heard both and had the catbypass on my car. on the 996, the catpass is as loud if not louder than the mufbypass. i can tell you that catbypass on my car is waaayyyy louders than the muffbypass in fabspeeds video. now go back to your room and finish your homework. you're not going to get an A in math if you spend all your time on the computer

 

everything is relative i suppose, especially when it comes to sound. the GT3 is pretty loud from the factory, especially when compared to the stock 3.6 liter cars. I have a hard time with the PSE mufflers being louder than stock mufflers with catbypass pipes. have you actually tried all these combinations or just heard variations on different cars? i'd love to hear a sound clip of a GT3 motor with stock exhaust pieces and the catbypass pipes.

I had aftermarket headers and mufflers when I tried the bypasses on my 3.6 liter. but quite honestly, the headers and mufflers themselves did not really increase the volume significantly maybe 10-15%. They did change the tone of the exhaust though. It wasn't till the bypass pipes went on there that my car got obnoxiously loud. I also have a cab so I'm probably hearing a lot more of what is going on with the exhaust than you coupe owners.

 

Well they are not for me. When I heard muffler bypass pipes on a GT3, the sound reminded me of a tractor pull...Pretty much a crappy resonating head pounding sound ....

 

exactly.

 

Im far from a noob , a porsche noob at that Anyway you just agreed on muffler bypass pipe's essentially being "obnoxious", just remmember, however loud something is on my car, will be twice as loud on you NA cars, so i have an idea especially since ive heard them on several cars and severl setups

 

Yes, I've tried every combination described above on my car. Looking for louder, without eliminating the metallic natural sound on the engine. This is the way it works on the GT3.

A very good friend with a 40th Anniversary 996 (3.6 wet sumper), installed the Fab muffler bypass pipes. To my surprise, it was not as loud. Same thing goes to 993s and muffler bypass pipes.

However, on the GT3 engine the muffler bypass pipes make the car extremely loud.

The PSE masked my engine sound, the MaxFlo had too much resonance and also masked my engine sound. The PSE on a GT3 is much more louder than the stock exhaust and cat bypass pipes, think 5.5 vs. 3.5 on the above scale. Right now I've the same sound as stock but a bit louder thanks to the cat bypass pipes.

 

didn't you just get this porsche? if i remember right, you had some sort of crazy HP M3 in the past.

yes, i agree the muffler bypass is obnoxious on the street too. very very loud.

so we're in agreement that stuff is louder on the NA cars due to the fact that the turbos eat up some of the noise?

 

i find it odd that the gt3 would exhibit different reactions to exhaust mods than the standard 3.6 liter. they can't be that different other than the higher performance internals, etc...

 

Of course we are in agreeance that NA sounds louder in every exhaust aspect then forced induction. The original arguement though was that muffler bypass pipes are more than twice as loud as cat bypass pipes alone

BTW im taking my race pipes off, its too a pint where i cant even enjoy my car when i take it out for a ride

 

wait till you get married. your exhaust choices will become a lot more limited