[TxBeem]

So I have done a lot of reading on downpipes and have seen dyno results on some DPs that can give you 15-20 HP gains and up to 30 lbs of extra torque but now my concern is the noise.
My intentions were to get DPs and get catback exhaust later on but now I'm hesitant to get DPs and exhaust together cause if the potential loudness. Is this a problem for any of you guys who have this setup?
I know for some loud means "better" but like anything there is "better" and there is "annoying". I live in a relatively quiet neighborhood. And my garage faces my next door neighbors bedroom. I would hate to start up my car at midnight to go get a snack or something

[TxBeem]

Oh! Forgot to ask. If I get catless DPs isn't that NOT going to pass emissions? Sorry for any ignorance but I'm not too familiar with DPs.

[chili36]

The noise is not bad at all. Just a more pronounced exhaust tone.
There are vids on YouTube.
No go on emissions.

[///M3THOD]

Originally Posted by chili36

The noise is not bad at all. Just a more pronounced exhaust tone.
There are vids on YouTube.
No go on emissions.

If you leave your secondaries in there are they not effective enough to pass a emissions test?

I am leaving in my midpipes because all of the cars I have heard with no cats in it have a certain "tinnyness" sound in the exhaust note. Some folks have got around this by custom resonators and whatnot, but in general its present.

[Blue Streak]

DPs do sound nice, but not really loud or an annoying drone. It sounds a bit like an E46 M3 actually.

[chili36]

Originally Posted by ///M3THOD

If you leave your secondaries in there are they not effective enough to pass a emissions test?

I am leaving in my midpipes because all of the cars I have heard with no cats in it have a certain "tinnyness" sound in the exhaust note. Some folks have got around this by custom resonators and whatnot, but in general its present.

I haven't touched the secondaries.
Buddy of mine failed with kittyless DP's

[AJ335]

is it high flow cat? or cat deleted? Dp with cat deleted will be louder for sure

[TX335]

Originally Posted by TxBeem

Oh! Forgot to ask. If I get catless DPs isn't that NOT going to pass emissions? Sorry for any ignorance but I'm not too familiar with DPs.

I am still learning about this myself (so anyone correct me if I am wrong), but I have read that TX emissions only look in the OBD port to see if the O2 sensors are throwing codes. So you could pass emissions with an O2 simulator. Other states like CA require a direct hookup to the exhaust, so going catless in the DPs will definitely fail that test.

Some tunes will delete the codes while you are running, but I've read that they don't allow the OBD port to be in a "ready mode." The port has to be in that "ready mode" to pass emissions.

Please correct me if I am wrong, but this is what I have read about so far.

[///M3THOD]

Originally Posted by TX335

I am still learning about this myself (so anyone correct me if I am wrong), but I have read that TX emissions only look in the OBD port to see if the O2 sensors are throwing codes. So you could pass emissions with an O2 simulator. Other states like CA require a direct hookup to the exhaust, so going catless in the DPs will definitely fail that test.

Some tunes will delete the codes while you are running, but I've read that they don't allow the OBD port to be in a "ready mode." The port has to be in that "ready mode" to pass emissions.

Please correct me if I am wrong, but this is what I have read about so far.

GA uses a sniffer in the exhaust line to test emissions, don't know what other states use. Seems like the OBD port would be an easily manipulated place to test for emissions.

[NiVeDh]

Originally Posted by ///M3THOD

GA uses a sniffer in the exhaust line to test emissions, don't know what other states use. Seems like the OBD port would be an easily manipulated place to test for emissions.

Actually, GA doesn't use a sniffer test.

All 1996 and newer vehicles will receive a three-part inspection:

* An OBD test to check your vehicle’s emission control performance history.
* A fuel cap inspection to check for adequate seal.
* A visual inspection of the catalytic converter to check for tampering or removal.

[vasillalov]

One other thing to add:

Check carefully your state emissions laws and regulations. Here in IL, your car is not due for emissions testing until it is 4 years old, which makes sense as most new car warranties last 4 years. So if the exhaust is system is broken, you get it fixed for free at the dealership.

So, if you do the math, my car which is a 2008 model, won't be due for emissions testing till the summer of 2012. Also, once the car passes emissions in IL, it won't be due for another 2 years.

Finally, check and see if your state has scan-only emissions stations. IL does have those. So for as long as your ECU tells them that everything is kosher, there is nothing to worry about.

I run hardware based O2 simulators and everything is fine. I see tons of heavily modded Subarus and Mitsubishi's passing inspections with full catless exhausts here all the time.

[madmanhiker]

If it's an n55, and you run a quality race exhaust with cat-less DP's... it will be loud. If you are in a conservative neighborhood, or are concerned (before even installing anything) then this may not be for you. The n54 definitely has a different exhaust note than the 55 and is 'slightly' softer and less harsh. CRAPPY videos below... but it gets the job done. I have some input from others who were there that day below the vids...

Video 1 - iPhone 4 Video - sound is 'ok' but much more exotic in person:

Video 2 - Flip video - sound seems a little better - Cold Start - Mar 13:

good luck in your decision........ it's NOT for everyone.

Originally Posted by e90TiAg335i

Car does sound AWESOME in person....Keeping myself from buying an exhaust is going to be sooooooo hard now...

Originally Posted by 1SerieStud

though the video has decent sound, it does NO justice to how it truly sounds in person. In fact, the video barely captured the incredibly loud spooling of the turbo which can be heard from the exhaust! Outstanding setup!

Originally Posted by Sloppy

Robert, I think i've listened to your vid more than 100 times LOL... just cuz thats how mine will sound like

It's loud - especially on cold start... BUT, it's intoxicating doing a slow pass past a car on the highway and this rich -totally European- grumble turbo spooling sound reverberates back to your ears....... I can't explain it any better. Full throttle is SEX.