Beretta.net

Im looking install a no-name aftermarket exhaust on a bone stock '96 3.1

my plan was to remove cat and resonator and run 2.5'' inch pipe throughout the car (this setup was from a youtube video i found on a beretta that sounded nice)

i went to a reputable muffler shop and said "i wouldnt remove the cat cause it would trigger a sensor and it would just melt your whole exhaust system away" and suggested that i should run 2.5'' from the cat on...?????

i think the guy is just bs about the effects on removing the cat..but what should i do?

I would leave the cat, the car really does need it to run properly. I could care less about the environmental aspects. If I were you, I would get a nice high flow cat. The HP gained from just straight piping the cat is minimal if any. But if you do I dont see your exhaust melting.

Upgrading your exhaust really starts at the downpipe, that's your biggest restriction. IIRC the OEM pipe is a double wall ram bent pipe, and it chokes it down to 1.5 or 1.75 I think.

As our cars have no sensors after the cat converter, removing it wont affect the engine management at any way. After hearing the comment about melting, I'd just change to another shop, either these guys have no idea what they are talking about, or they just don't want to service you.

Hp gain from removing the cat is usually not that much (if the cat is fully working condition), but it does gain quite a lot of low to mid end torq.

Thats not true weba, he has a 96 so yes he has a post cat O2 sensor... its OBDII. Removing the cat will throw a code and he will not pass local emissions if they do a ECU code check on 96+ cars.

Only thing the code says is insufficient cat efficiency so it is only a emissions code and it will not melt your whole exhaust system... Where the hell do people like that come from... Some of the crap I hear "shops" say just blows my mind and I have NO idea how the hell they got their job to begin with.

With my car being tuned I have that code shut off and the sensor completely disconnected so I run like a 95 car would... I also have a section of pipe that has a 3" exhaust dump followed by a hollow cat, so when I go to the strip I'm running a car with no cat on it. And to add to the brilliance factor of the shop... a large deal of exhaust temps are produced by the CAT since it's technically cooking off the gases... its reaction generates A LOT of heat and is typically the hottest part of your exhaust system at times.

Just a word of caution. A standard muffler shop 2.5" exhaust flows about as good as a 2.125" OD straight pipe due to the amount most places crush it. The factory piping actually flows near a 1.875" OD straight pipe IIRC. The real way to increase performance and remove some of the buzz noise is going mandrel bent. On a 3100 car 2.25" piping is best, mandrel bent of course. If you can't get mandrel bent (many places will claim this but they are actually lying) then 2.5" press bent (not crush) is the next best option.

I use a SS 2.5 pipe from wicked-irocz. 3 inch from the headers, then reduces to 2.5 into a gutted cat and is straight piped to a dynomax muffler. The cat keeps a lot of the stupid ricer rasp away. My car sounds good at lower rpms but at 6600 it sounds like a can of crap. It also gets a weird rasp decelerating when im at high rpms.

I would keep the cat if I were you, it wont hurt you too much on a stock motor, assuming you dont tune your engine.

The rasp is much more apparent on a glass packed type muffler. Chambered will give a completely different tone. The best sound I ever had was 2 1/2 pipe through a cat, then through a Moroso Spiral muffler as a resonator and then my 80series flowmaster... At least I thought that sounded the best.





I like that sound even over what I have currently.

Your car now sounds like I imagine a wet dream would sound like.

Well the lope yes, and low RPM but at WOT its a bit harsh... lol I think once I get my torque converter fixed and it doesn't rev so high all the time it will sound a bit better.

Any vids of high rpms and letting off from redline? Mine sounds fine at idle too but up top is where it hondas out

On which car? I also don't take vids of me ripping up the streets and post them on youtube so I don't have stuff like that really... Only WOT vids I have are at the strip and are open exhaust with other dragsters drowning me out.

I haven't found a resonator muffler combo for a quad that doesn't Honda out before 4 grand. I still have 3500 rpm of power band after that.. lol

Chad91GTZ wrote:I haven't found a resonator muffler combo for a quad that doesn't Honda out before 4 grand. I still have 3500 rpm of power band after that.. lol

Unequal length headers and you'll sound like a Subi... well Maybe... LOL

I just did the exhaust on that and DAMN talk about ANTI Honda... Gotta love that Boxer purr.

kk i appreciate it guys..so im guessing im going to stick with my cat and go with 2.25 or 2.5 piping from the cat on and install my muffler i got...sometime in the future ill get a hi flow cat

I would recommend if your going to do that, just take the factory muffler off and put your muffler of choice on. Upgrading the piping one piece at a time like that is really not worth anything.