Aatish

I think I know the answer, but will ask.

Anybody on here have just the x-pipe, or ran just the x-pipe before headers and cats?
How much louder was it than stock?
This thing is too quiet for me. Want to do something, but if the X-pipe isn't that effective, I'll just go catless and wait for other options down the road.
I'm planning on getting tuned, not too worried about CEL. How are the O2 spacers with the catless. Will the AFR be affected by the mislead values from the downstream sensor? Asking, because my F30 had issues when I messed around with the sensor voltage to trick the DME into readiness (ran really rich).

All and any input (that's constructive and relevant) is appreciated.

Lambomike58

computertom

LavaGTS

definitely go catless. Leave PSE alone on .2 cars IMO

Aatish

Thanks for the input.

On the N/A cars, the X-pipe helps a lot. However, I'm suspect as to if it will be as dramatic on our twin-snail cars. I do think the stock muffler is effective at muffling the sound, however I also feel that that cats are what really kill the.

Sigh, nobody on these forums posts videos of their setups :/

Aatish

I love this thing, except for the sound. Hate the PSE look. Twin side exit look way better. Don't get me wrong, sounds ok. But way too muffled and quiet. Part of me wants to just straight pipe it from the cats back....but I think that might be overkill.
Cobb tune will be nice too...

Aatish

Plan is to eventually go catless, but want some tune to go with it to take advantage of the reduced back pressure.
That said, if the x-pipe isn't that effective at giving me the sound I want, I may have to just do it and wait.

drcollie

It makes no sense to pull cats in a modern engine in my opinion. You are not going to see an increase in performance, you're smogging, and all the engine management software is designed to work with them. For a full-on race car - fine, but street car? If you just want to make more noise, then go with a high flow cat, that will do the job for you. Be prepared for it to be so loud that you may have no need for a stereo in the car or phone bluetooth, however.

Lambomike58

stout

+1

Some call cat delete a dirtbag mod. Whatever the case, it's illegal and harmful to you as well as everyone around you...for little if any gain in performance.

Far better to delete the mufflers than the cats if you want more sound. That's how the Abarth runs, and it sounds great with just a turbo and a catalyst to "quiet" it. Interestingly, the new GT2 RS very nearly had no mufflers. They only had to add a muffler system back in when they went to bigger turbos for 700 hp. Borla is working on a system for the 991.2, and it would be interesting to give Fister a 991.2 to see what they can do in modding the stock mufflers. I agree...the car could use a bit more voice. An ideal scenario would see the stock mufflers modded in stages according to personal preference.

Aatish

While I respect your opinion, I must disagree to some point.

On a stock car N/A car going catless probably won't do much in terms of power. On a stock tune turbo charged car, going catless will relieve back pressure on the outlet of the turbine assembly, however the car probably won't be able to make a lot more power alone. Turbine will encounter less compressed exhaust gasses (since there is no catalytic structure in the way), which will allow it to each its peak rpm significantly faster. However, not much power will be made, I agree.

On a tuned turbo charged car, playing around with catless or a high flow cat is necessary. The increased boost target set by the tune will require the turbo to move a lot more air. The reduced back pressure will not only help it achieve this higher level of boost, but also allow it to maintain it at a constant level.

Now, catless or high flow cat. Usually, tuned car tend to run a bit richer to prevent detonation. This also means richer exhaust gases when compared to stock. The richer exhaust gases exiting the engine would require a lot more work to be neutralized effectively. Personally, a catted pipe seems like a waste as the exhaust gases exiting will work it a lot more than stock. Catless has nothing that affects the gases, therefor nothing to worry about burning out.

Then theres antilag. Never run cats with antilag systems.

I get it's bad to environment and illegal. I haven't had any issues with the law because of it. Does it smell? Yes, I kinda like it. Is it loud? Yes, but not unbearable if exhaust setup is done correctly.
I respect your opinion, but we both go to different Churches. Nothing wrong with that. But I requested constructive responses only for this thread. I'd appreciate it if you could refrain from bashing catless.

PJ Cayenne

I don't think it is that weak. I hear some pretty neat sounds out of my 3.0tt over 3,000 rpm. Much better when the sunroof is open. I listen to a lot of music when I drive, and plenty of engine noise comes through. Sometimes quiet is ok too.
Look, we have to realize, it breathes though intercoolers and turbochargers. Plus a smaller displacement engine will not sounds as full as larger mills. I have the dual double tips in black and love them. Glad I saved the money for the PSE.

LavaGTS

Can you prove your first statement? I can disprove it for you.

Here:

Bone stock GTS.. 11.5 @ 121 mph.. Roughly 75 degrees outside.









Add bypass pipes.. 11.2 @ 123 mph.. Temperature in the high 80's


As for your second satement.. That's also wrong. I have no drone and with PSE off the cabin in completely silent of exhaust noise..

You must remember that these are TURBO cars. TURBOS ACT LIKE RESONATORS. If you straight pipe an NA engine it's gonna sound like **** as you mentioned.



Rennlist.. The worst place to go for technical information on the internet.

stout

All good to have different views, except you're making everyone around you go to your church while poisoning them and their kids too. That neighbor next door, that family in a minivan behind you. That isn't an opinion, it's a fact. And for what? A few ponies? Quicker spool?

I get the desire for both. But...high-flow cats are a bit like speeding from time to time: still within the realm of reason, and a lot of folks do it. Catless is a bit like speeding all the time, blowing through school zones at 40-50+ mph. Your neighbors might look at you and shake their heads, while that nice officer who might give you a warning for speeding on a freeway or deserted road is likely to lock you up for the night.

As for sound, I'm in your camp and am thus curious about your thread and here to be constructive—so please don't view the above as angry...more as a vote for high-flow cats and/or mufflers as a better way to find what you're looking for. Old cars (like the one in my avatar) were dirty. New cars are in many cases faster, and MUCH cleaner. Why toss that out the window? I think you can achieve what you are after with exhaust alone (as your thread asks about) and/or high-flow catalysts. And I am interested to hear people with experience weigh in, too.

I think your thread is actually something of a trailblazer, as there are a lot of people who skipped PSE for reasons of cost or looks and wouldn't mind spending some money on a revised exhaust setup. Borla, Fister, Sharkwerks, etc all have a record of making Porsches sound better in the past, so it will be interesting to see if they offer something for the 991.2. I'm also curious about sound deadening changeover to the T stuff, which I hear is more extreme than the GTS setup.

Aatish

I'm quickly realizing this lol.
Nice times btw.