[headlee103]

Originally Posted by dtc100

Looked and sounded great! Is there noticeable performance gain with such mod? Seems to me to have any gain the exhaust will have to sound very aggressively different from the stock, but not this one.

Theres no gains at all

[dtc100]

Originally Posted by headlee103

Theres no gains at all

Thanks! One of the nicest looking mods I think.

[DESI4life10]

Looks really good. Nicely done.

[5erman]

wow I bet you lost some HP there-those are some sharp ass bends coming off the muffler to the right end of the car-that will realllly hamper velocity of flow at the end and back up the gases-probably isnt a huge deal but doesnt look like a very efficient exhaust routing no?

[1QuikWS6]

Originally Posted by 5erman

wow I bet you lost some HP there-those are some sharp ass bends coming off the muffler to the right end of the car-that will realllly hamper velocity of flow at the end and back up the gases-probably isnt a huge deal but doesnt look like a very efficient exhaust routing no?

Actually, as the exhaust gases cool out toward the end of the car - the velocity increases naturally

[EmjayDavis]

Im still wondering this sound sounds similar to a OEM exhaust but more clean in a way..
does this lose OR gain HP?

[5erman]

Originally Posted by 1QuikWS6

Actually, as the exhaust gases cool out toward the end of the car - the velocity increases naturally

ya not quite. Cooler gases flow more slowly not with more velocity. That is why RPI exhausts make power is they have a tapered end that decreases pipe length as it moves down the car to keep the velocity up as the gas cools and therefore SLOW's down.

have you not taken basic chemistry? or physics-cold molecules move more slowly and hot ones move fsater. Larger diameter pipe moves slower velocity and smaller with faster velocity. Same with big bends in pipes decreaseing velocity.

but enjoy the loss of power-sweet 328 wiht a huge 230 hp and subtract 15--good deal

[1QuikWS6]

Actually you are correct, my bad it was early and apparently I was still asleep. I did take Chemistry - and hated it

Hot gas=faster/cold gas=slower that is why wrapping your headers or exhaust pipes with the ceramic wrap to help hold the heat in aids in exhaust scavenging.

My T/A has Jet Hot coated Hooker headers inside & out as well as the rest of the exhaust piping back to the chambered 'mufflers' Coated on outside to keep surrounding areas cooler from radiant heat, coated on inside to retain the exhaust temp thru the system.

Exhaust system is pretty much a science by itself & you could write a book on it. Important factors starting with the:

Headers
Primary diameter
Length of each primary tube based on cylinder/firing order (contrary to popular belief, equal length primary tubes do not necessarily flow better than unequal lengths)
Type & amount of bends in each primary tube
Collector length

On to:

Main Pipes
Diameter of pipe
V8 engines like a Balance Pipe - X pipe or H pipe in system at the correct point behind the collectors to balance the exhaust pulses
Type/amount of bends in system

Then to:

Muffler

Most people buy a muffler based on the inlet/outlet size and how loud it is - thinking that bigger is always better and louder flows more.

Actually, the innards of the muffler are most important. The engine doesn't care what size the muffler pipe diameters are, but it certainly does care what the muffler flows, and muffler flow is largely dictated by the design of the innards. They should be designed so the muffler 'sees' no loss of flow thru body compared to in & out pipes. A glasspak muffler is loud & by it's outward appearance lends one to believe it flows well. Actually a Flowmaster muffler with it's tuned baffles may seem more restrictive, but it flows better than a glasspak. At some point the muffler will cease to increase flow because system will only flow as much as smallest component. Increasing muffler flow unlocks potential engine power. Once all the potential power is unlocked, further increases in exhaust system flow will not produce any further benefits in terms of power So at some point the loudness is just wasted as it isn't really flowing any better.



In terms of flow, an inlet, muffler and outlet that appears to the airflow to look like #1 is what is needed. A real-world muffler (#2) does not look like #1, but #4. This shows that the muffler, not the pipe, is the usual restriction. Some race mufflers actually have a core flow greater than the in/out pipe and look like #5.

Tailpipes
As far as power is concerned, tail pipe length after the mufflers has no measurable effect on the power if a large change in cross section is present up stream (toward the motor) of the tail pipe. An open-type muffler, or a resonator box, provides this cross-sectional change.

Exhaust scavenging process is, in effect, a fifth cycle in the combustion process contributing to total power output.

The exhaust system on a well-tuned race engine can lend a partial vacuum as high as 6-7 psi at the exhaust valve at and around TDC - which not only helps in getting exhaust out, but also aids in induction, because this occurs during the overlap period where as much as 4-5 psi of this partial vacuum is communicated thru the open intake valve to the intake port.

[headlee103]

Originally Posted by EmjayDavis

Im still wondering this sound sounds similar to a OEM exhaust but more clean in a way..
does this lose OR gain HP?

WOW I didnt realize that a simple "cosmetic" mod would stir up such a debate! haha I simply did this because my OEM bumper was scuffed up and I received a free OEM Aero Rear bumper, and thought it would look cool.

At no time did I think about the HP gains or losses... I mean lets be serious, Im not gonna be out racin anyone anytime soon. The only performance mods that I have are AFE Intake and PBX, but got those mostly to get rid of the lag.

Whenever I first drove the car after getting the exhaust done, I didnt notice any significant changes, in fact nothing at all. But I like it, I think it looks good and it sounds great!! I get compliments on it all the time. In fact a few weeks ago, I went to the dealership and the SA asked if it was the BMW Performance exhaust so I guess it sounds pretty good!

Not tryin to bash anyone, just thought I would make it clear that this mod was all for looks. If I take a slight loss in power its not gonna upset me too much.

[SR2007]

What did they do exactly about that compartment on the right side. I looked under there and really didnt know what to do. I've been looking into doing the conversion myself, but dont want to buy bumper without know what mods will need to be done to run that right side pipe. Did they remove anything? All i see is plastic shell with and didnt want a gaping hole if i remove the cover. Any help would be awesome thanx.

[Chewy734]

Looks awesome man! I'm glad you went with SST piping.

[EmjayDavis]

Originally Posted by headlee103

WOW I didnt realize that a simple "cosmetic" mod would stir up such a debate! haha I simply did this because my OEM bumper was scuffed up and I received a free OEM Aero Rear bumper, and thought it would look cool.

At no time did I think about the HP gains or losses... I mean lets be serious, Im not gonna be out racin anyone anytime soon. The only performance mods that I have are AFE Intake and PBX, but got those mostly to get rid of the lag.

Whenever I first drove the car after getting the exhaust done, I didnt notice any significant changes, in fact nothing at all. But I like it, I think it looks good and it sounds great!! I get compliments on it all the time. In fact a few weeks ago, I went to the dealership and the SA asked if it was the BMW Performance exhaust so I guess it sounds pretty good!

Not tryin to bash anyone, just thought I would make it clear that this mod was all for looks. If I take a slight loss in power its not gonna upset me too much.

Regardless the car sounds and performs amazing!

[hellaastoops]

sounds amazing

[Das.Euro]

Sounds great, i doubt he did the mod for any gains guys lol seriously ...If you want real gains, you work header back.. I might go this route actually with that muffler but delete the 2nd cat and leave res in. All for sound for me

[bannana speed]

Nice

[Jay4King]

Where can i get that rear skirt at, for a 2010 328i?

[jaceaholic]

Originally Posted by Jay4King

Where can i get that rear skirt at, for a 2010 328i?

are you a e92 or e90??

[headlee103]

Originally Posted by Jay4King

Where can i get that rear skirt at, for a 2010 328i?

You can get it from Tischer... its an OEM bumper

[oaks88]

so you got the bumper from tischer? how about the tips? where can I pick some of those up?

[mastermayhm]

clean work you got there bud

[ChristianX]

how much did the piping and labor cost?

[Jason]

Cleaned up. No condescending attitudes or intra-model hating will be tolerated.