[ThaPaki]

Yup just got paid and I wanna do a muffler delete on it. What are you guys opinion? I think it will sound dope!! Thanks for the info!

** went ahead and did it! Love the sound. But now I hear a high pitched noise when I'm in manual mode. If your wondering I cut off the muffler got a pipe molded and kept the stock tips and pushed em out 3 inches!

[AlpineSwift]

I've heard a few N55's through youtube with it done. If it's anything like mine its gonna be loud as hell. No idea what the drone is gonna be like but I will say windows up cruising on the highway it doesn't wear me out and I don't have t raise my voice above a whisper if I don't want to.

Again, take my opinion with a grain of salt if you wish but be warned; if you get DP's after doing a muffler delete, you're gonna wake the dead and ruin your hearing.

[ThaPaki]

Originally Posted by AlpineSwift

I've heard a few N55's through youtube with it done. If it's anything like mine its gonna be loud as hell. No idea what the drone is gonna be like but I will say windows up cruising on the highway it doesn't wear me out and I don't have t raise my voice above a whisper if I don't want to.

Again, take my opinion with a grain of salt if you wish but be warned; if you get DP's after doing a muffler delete, you're gonna wake the dead and ruin your hearing.

Hahaha that's the plan. Currently looking for dps man

[AlpineSwift]

Well if you want every cop in 5 miles to know where you are, go for the muffler delete with DP's.

[135Pats]

Originally Posted by BMW..

Just got my N52 done. Obviously the engines are different but honestly it sounds like SEX. I have no clue why anyone would ever call it lame or ricer. It is crazy how excellent our cars sound like. DO IT!

Your N52 doesn't have a twin scroll chopping up exhaust gasses and adding in a ton of drony boom....NA motors always sound sexy when you open things up.

FI is much more difficult to get a nice tone out of.

OP a muffler delete with catless dps will be ferociously loud and boomy. Inside the cabin the resonance will be ridiculous. If that's what you want go for it...but prepare for a wall of noise.

[OmidHariri]

Don't you lose a bit of low end torque?

[ThaPaki]

Originally Posted by OmidHariri

Don't you lose a bit of low end torque?

I believe unfortunately so -_-

[135Pats]

Originally Posted by OmidHariri

Don't you lose a bit of low end torque?

Doubt it.

Honestly there is no cat back product on the market that will produce sizable gains in power...Maybe if it's a terrible design you'd have a small loss. But it's so far downstream at that point, there are no real gains to be had.

[AlpineSwift]

My observations of what the pro tuners and shops have said on here regarding N54's and N55's, the bigger the exhaust (less restrictive) the better. The more exhaust the engine can push out as quickly as possible, the better the turbos tend to perform which produces more power. There is a trade off though. For the people running ST's, there comes a point where to big is too much of a trade off. The larger the exhaust, the slower the spool time on the turbo.

Ideally, you want the shortest and fastest route to getting the exhaust out of the system for the best performance numbers. Because that isn't exactly legal on the road, you have to find a happy medium. Finding a happy medium means finding the ideal power numbers that won't kill your turbo spool.

NA motors like the N52 need the back pressure (proper flow rate in the exhaust piping behind the exhaust manifold) to keep the proper fuel curve that the engine was designed for. Without this balance, the engine loses low end torque due to an unaccounted lean fuel curve. What ultimately comes into play is finding the right diameter piping for the most efficient power across the entire RPM range (ideally the fastest flow rate while keeping the pressure of the exhaust gases low but not so low that lose your low end power). Reversion happens more often on too small of diameter piping. Fast flow, but also high pressure. This high pressure stops up the exhaust flow and allows the spent gases to be ingested back in through the exhaust port of the engine along with the unspent fuel/air mixture. This among other things causes engine knock (if you've got too small of an exhaust for the tune/power mods you're running) and robs the engine of power. This is why most if not all engines see increases in power when even a simple cat back exhaust is installed.

I hope this makes sense. Tried to make it as simple as possible and I've likely left out a lot of good information.

[patrick335i]

Originally Posted by ThaPaki

I believe unfortunately so -_-

What part of moval you live in bro? I have a white 335i, I may have seen you ebfore lol

[ThaPaki]

Originally Posted by patrick335i

What part of moval you live in bro? I have a white 335i, I may have seen you ebfore lol

Hahaha you seen team impact ride around Moval? I live off cottonwood be we be posted at day st!

[patrick335i]

Originally Posted by ThaPaki

Hahaha you seen team impact ride around Moval? I live off cottonwood be we be posted at day st!

nah I dont know of team impact.. you should introduce me lol, I live in shadow mountains like 2miles from cottonwood

[OmidHariri]

Originally Posted by 135Pats

Doubt it.

Honestly there is no cat back product on the market that will produce sizable gains in power...Maybe if it's a terrible design you'd have a small loss. But it's so far downstream at that point, there are no real gains to be had.

Talking about the muffler delete

[mashimarho]

I would avoid the muffler delete if I were you. Had a friend of mine do it, and he complained it sounded like a civic.
Treat your car nicely, and buy it a decent exhaust, and it will treat your ears well in return. BMW PE would be your best bet. You can find a set for about a grand or less shipped.

[135Pats]

Originally Posted by OmidHariri

Talking about the muffler delete

Me too.

A muffler delete is most certainly aft of the primary cats.

If you want tons of rasp and boomyness, go for it. But don't worry about power with a muffler delete or whatever, it's marginal stuff. Midpipe swaps could net you a handful of WHP perhaps...

[AlpineSwift]

Originally Posted by mashimarho

I would avoid the muffler delete if I were you. Had a friend of mine do it, and he complained it sounded like a civic.
Treat your car nicely, and buy it a decent exhaust, and it will treat your ears well in return. BMW PE would be your best bet. You can find a set for about a grand or less shipped.

Civic huh?
http://www.youtube.com/watch?v=yrewAmTKWI0

Not sure what to make of this but its a far cry from a civic.

[SRT14PimPin07]

I had a muffler delete on my car for over a year and was very happy with the sound, and I got used to the drone after a month or two. But once I put the cat-less DP I was gonna kill myself. It sounded like shit, IMO. WAY TOO LOUD! But I was ready for that, I had my BMW P.E. at home. And slapped it on the next day. COLD Start with no muffler and Cat-less DP WAS INSANE!!!! Too intense for every day driving. But once I put the BMW P.E. on it, it sounded like sex! Hope this helps!

[bk335ilci]

Some one just added this video n55 with muffler delete.

http://www.e90post.com/forums/showthread.php?t=929365

[Andrewe92]

OP.. you can catch me writing this is every thread that has to do with someone wanting to get a muffler delete, anyway imho i say don't do it because from a performance aspect I believe you will lose some torque on the lower end of the rpm band, because the mufflers actually do built up some kind of back end pressure... don't get me wrong its a mod that will get you something that sounds great and its not even pricey.
also i can say from experience that the loss wont be much numbers wise but you might feel the difference yourself as you drive it.

[AlpineSwift]

Originally Posted by Andrewe92

OP.. you can catch me writing this is every thread that has to do with someone wanting to get a muffler delete, anyway imho i say don't do it because from a performance aspect I believe you will lose some torque on the lower end of the rpm band, because the mufflers actually do built up some kind of back end pressure... don't get me wrong its a mod that will get you something that sounds great and its not even pricey.
also i can say from experience that the loss wont be much numbers wise but you might feel the difference yourself as you drive it.

Back end pressure/back pressure is the uneducated term for flow rate.
http://www.e90post.com/forums/showpost.php?p=15182941&postcount=10

As stated, not by myself, but tuners on this platform and many other turbo powered vehicles; They do not need "back pressure" for horse power or torque. The size of the pipe has a direct impact on turbo spool. Butt dyno's are invalid in this instance.

If you need some more info, I'd be happy to provide basics on exhaust.

[Andrewe92]

Originally Posted by AlpineSwift

Back end pressure/back pressure is the uneducated term for flow rate.
http://www.e90post.com/forums/showpost.php?p=15182941&postcount=10

As stated, not by myself, but tuners on this platform and many other turbo powered vehicles; They do not need "back pressure" for horse power or torque. The size of the pipe has a direct impact on turbo spool. Butt dyno's are invalid in this instance.

If you need some more info, I'd be happy to provide basics on exhaust.

the link you posted isn't working.. also I must of been thinking of my 328 when I had one. because when I got the muffler delete.. I really felt the loss of torque but of course it's ok for me to be wrong since this is not a n/a engine ..but still I will look further into it! try providing the link you meant to post again thanks

also if this is the case wouldn't you gain a little power or torque.. I think thats the case

[AlpineSwift]

Fixed
http://www.e90post.com/forums/showpost.php?p=15182941

Turbos created exhaust pulses in rapid succession that are substantially larger and higher in pressure than that of N/A exhaust pulses.


This image represents an oversized 3" pipe on both an NA car and a Turbo car. Notice the NA cars pulses bouncing around and not following in a line? This causes the power loss associated with having too large of a pipe for the power output of the engine the exhaust is attached to. Because of the way Turbo cars produce their power, it doesn't matter how large the pipe is, it will not have the same power loss as an NA car because of how the exhaust pulses are produced. However as mentioned, if the pipe is made to large, rather than lose power it will take longer to spool the turbo because the there is less exhaust pressure to force the turbine to accelerate.

Hope this clears up the confusion.