Theory Behind OEM Exhaust

E90330iS · 01-10-2009, 01:55 AM

I've done some research about OEM Exhaust and Aftermarket exhausts. It seems that aftermarket exhausts are nicer sounding and lighter. Now here is my question: why would BMW use more precious metal and make a heavier exhaust with many sound-numbing devices? Are they making a market for their BMW Performance products? Or BMW really wanted to make 3 Series a quiet, subtle ride? thanks for responses in advance.

Year's_End · 01-10-2009, 02:12 AM

Quote:

Originally Posted by E90330iS

Or BMW really wanted to make 3 Series a quiet, subtle ride?

Most likely.

Bimmer Nerd · 01-10-2009, 02:24 AM

Quote:

Originally Posted by Bimmer Loyalist

Most likely.

yea but doesn't the back pressure of the OEM exhaust great more trque ? because of the restricted air flow i think it gives you more torque, not 100% sure on that but i think i have heard it somewere.

E90330iS · 01-10-2009, 02:27 AM

Quote:

Originally Posted by godora

yea but doesn't the back pressure of the OEM exhaust great more trque ? because of the restricted air flow i think it gives you more torque, not 100% sure on that but i think i have heard it somewere.

Actually Tischer BMW just advertised that the BMW Performance Exhaust reduces back pressure and produces more power. CONFUSING RIGHT?

wj4 · 01-10-2009, 02:28 AM

Just like with all other OEM exhausts, this is no different. The goal is to be quiet as possible.

Even with the stock exhaust, my mom thinks it's loud.

When using materials like titanium, it's true that it will be a lot lighter, but it will also be a lot thinner which means LOUD.

Bimmer Nerd · 01-10-2009, 02:29 AM

Quote:

Originally Posted by E90330iS

Actually Tischer BMW just advertised that the BMW Performance Exhaust reduces back pressure and produces more power. CONFUSING RIGHT?

but thats the performance exhaust, i was talking about like 328i ones. the 335i sounds aftermarket as it is, very nice sound imho.

E90330iS · 01-10-2009, 02:46 AM

Quote:

Originally Posted by godora

but thats the performance exhaust, i was talking about like 328i ones. the 335i sounds aftermarket as it is, very nice sound imho.

The BMW Performance Exhaust is actually made for 328i, 330i. It is the double tip design on one side of the bumper. I was actually referring that Tischer BMW says that the reduction of backpressure creates more power while the general consensus claims that backpressure increases power.

galahad05 · 01-10-2009, 04:16 AM

Increased backpressure can increase torque down low in the RPM range, but usually at the expense of horsepower up top.

This is for naturally aspirated engines!

When you go turbocharged, backpressure is rarely a good thing.

Bilka · 01-10-2009, 04:23 AM

Im sure the demographics for BMW owners has to be more than 60% in the 40+ range. And at that age, their owners dont want to hear their exhaust like we do in the 20-35 range.

vAnt826 · 01-10-2009, 05:32 AM

Surprisingly, the stock 335i cold start with the golf tee is loud.

Very loud, as in I can hear it on the 3rd floor loud.

Also, backpressure is a big NONO for FI.

hanmaas · 01-10-2009, 05:40 AM

Quote:

Originally Posted by godora

but thats the performance exhaust, i was talking about like 328i ones. the 335i sounds aftermarket as it is, very nice sound imho.

it's only for sound purposes on both models. that topic has been beaten to death in numerous other topics.

John 070 · 01-10-2009, 07:48 AM

People often seem to assume aftermarket > OEM, and tune their vehicles from the comfort of their LazBoy over wireless internet. Before variable timing people used to swap cams because they knew better than the engineers at the mfg.

I know that my OEM exhaust on my Nissan has been there 11 years, and has no hint of needing a replacement. That's not good news for the Midas or Stillen Motorsports of the world, who would have sold 4 exhaust systems by now to someone who replaced the OEM for the 3-5 HP gain.

BMWs4ever · 01-10-2009, 10:09 AM

Quote:

Originally Posted by DineshD

Im sure the demographics for BMW owners has to be more than 60% in the 40+ range. And at that age, their owners dont want to hear their exhaust like we do in the 20-35 range.

I'm 41 and I'd love to hear more of the exhaust sound

I wish they made the 328 a little more closer to the sound of the 335

ejazbmw · 01-10-2009, 10:17 AM

i don't any bmw exhaust beside the ///M's all 3 series are to soft and quite for my taste, i prefer the G37 exhaust now that sounds good

mmm def · 01-10-2009, 10:31 AM

I just don't like having the same thing as everybody else, stock is great don't get me wrong, but I like to make my cars a little unique.

demosthenes · 01-10-2009, 11:01 AM

Quote:

Originally Posted by sf_loft

Not everyone wants to hear droning in their cabin. The average age of 3 series owner is like in the 40's. The majority, including myself, think that the stock exhaust sounds great and is a balance between luxury and sport. Too loud, the cabin experience suffers, too soft, its no longer a sports car.

+1

CirrusSR22 · 01-10-2009, 11:28 AM

They need to be mass produced, durable and cheap. I'm 28 and it's been many years since I've wanted a loud exhaust. Loud cars are annoying.

My 318ti has spent 12+ years and 175,000 in salt country and just has slight surface rust. Trust me, stock BMW exhausts are very high quality.

ejazbmw · 01-10-2009, 11:51 AM

Quote:

Originally Posted by sf_loft

Have you ever picked up a book?

actually no i cheated my way through college English

noro · 01-10-2009, 11:54 AM

Most countries have very strict rules about dB levels of the car, that's why they have the soft pad under the hood, a closed up air intake system and a subtle exhaust sound.

Not to mention that most people do prefer a quiet car.

gtrokin330 · 01-10-2009, 12:03 PM

my 335 is extremely loud with the gold tee mod on a cold start. Imo the stock exhaust really is loud enough..

5soko · 01-10-2009, 12:03 PM

Quote:

Originally Posted by vAnt826

Surprisingly, the stock 335i cold start with the golf tee is loud.

Very loud, as in I can hear it on the 3rd floor loud.

Also, backpressure is a big NONO for FI.

haha my neighbors dont like the golf tee mod hahahaha COLD STARTS FTW>

HermesRider · 01-10-2009, 12:44 PM

Quote:

Originally Posted by gtrokin330

my 335 is extremely loud with the gold tee mod on a cold start. Imo the stock exhaust really is loud enough..

Adding precious metals to your exhaust helps even more?

01-10-2009, 01:55 AM	#1
E90330iS Major General 143 Rep 6,333 Posts Drives: BMW M4 Join Date: Jan 2006 Location: Arcadia, California iTrader: (56) Garage List 2006 330i [0.00]	Theory Behind OEM Exhaust I've done some research about OEM Exhaust and Aftermarket exhausts. It seems that aftermarket exhausts are nicer sounding and lighter. Now here is my question: why would BMW use more precious metal and make a heavier exhaust with many sound-numbing devices? Are they making a market for their BMW Performance products? Or BMW really wanted to make 3 Series a quiet, subtle ride? thanks for responses in advance. __________________ 2017 BMW M4 DCT Lease Transfer: https://f80.bimmerpost.com/forums/sh...8#post23736398
	Appreciate 0 Tweet Quote

01-10-2009, 02:28 AM	#5
wj4 Major General 335 Rep 7,719 Posts Drives: E90 manual 335i Join Date: Nov 2006 Location: Burbank, CA iTrader: (8)	Just like with all other OEM exhausts, this is no different. The goal is to be quiet as possible. Even with the stock exhaust, my mom thinks it's loud. When using materials like titanium, it's true that it will be a lot lighter, but it will also be a lot thinner which means LOUD.
	Appreciate 0 Quote

01-10-2009, 04:16 AM	#8
galahad05 Brigadier General 158 Rep 3,158 Posts Drives: '07 335i e90 Join Date: Mar 2008 Location: Long Island NY iTrader: (0)	Increased backpressure can increase torque down low in the RPM range, but usually at the expense of horsepower up top. This is for naturally aspirated engines! When you go turbocharged, backpressure is rarely a good thing. __________________ Always do right. This will gratify some people and astonish the rest. --Mark Twain
	Appreciate 0 Quote

01-10-2009, 04:23 AM	#9
Bilka Captain 32 Rep 714 Posts Drives: M440 GC Join Date: Nov 2008 Location: So Cal iTrader: (2)	Im sure the demographics for BMW owners has to be more than 60% in the 40+ range. And at that age, their owners dont want to hear their exhaust like we do in the 20-35 range.
	Appreciate 0 Quote

01-10-2009, 05:32 AM	#10
vAnt826 Major 63 Rep 1,417 Posts Drives: E92 M3 Join Date: Nov 2006 Location: Seattle iTrader: (3)	Surprisingly, the stock 335i cold start with the golf tee is loud. Very loud, as in I can hear it on the 3rd floor loud. Also, backpressure is a big NONO for FI.
	Appreciate 0 Quote

01-10-2009, 07:48 AM	#12
John 070 Lieutenant General 1705 Rep 14,829 Posts Drives: 335i cpe Join Date: Oct 2006 Location: ZSP/ZPP/ZCW iTrader: (0)	People often seem to assume aftermarket > OEM, and tune their vehicles from the comfort of their LazBoy over wireless internet. Before variable timing people used to swap cams because they knew better than the engineers at the mfg. I know that my OEM exhaust on my Nissan has been there 11 years, and has no hint of needing a replacement. That's not good news for the Midas or Stillen Motorsports of the world, who would have sold 4 exhaust systems by now to someone who replaced the OEM for the 3-5 HP gain.
	Appreciate 0 Quote

01-10-2009, 10:17 AM	#14
ejazbmw blahhh 302 Rep 6,355 Posts Drives: 2014 M235I Join Date: Apr 2007 Location: NJ/NY iTrader: (7)	i don't any bmw exhaust beside the ///M's all 3 series are to soft and quite for my taste, i prefer the G37 exhaust now that sounds good
	Appreciate 0 Quote

01-10-2009, 10:31 AM	#15
mmm def Colonel 144 Rep 2,610 Posts Drives: 21 330, 19 ND2 RF, 11 RX350 Join Date: Dec 2006 Location: NJ iTrader: (0)	I just don't like having the same thing as everybody else, stock is great don't get me wrong, but I like to make my cars a little unique.
	Appreciate 0 Quote

01-10-2009, 11:28 AM	#17
CirrusSR22 Major 342 Rep 1,325 Posts Drives: BMW Join Date: Apr 2005 Location: Minnesota iTrader: (0)	They need to be mass produced, durable and cheap. I'm 28 and it's been many years since I've wanted a loud exhaust. Loud cars are annoying. My 318ti has spent 12+ years and 175,000 in salt country and just has slight surface rust. Trust me, stock BMW exhausts are very high quality.
	Appreciate 0 Quote

01-10-2009, 11:54 AM	#19
noro Colonel 90 Rep 2,707 Posts Drives: '91 M3, '04 E46 ZHP, '72 2002 Join Date: Aug 2006 Location: Boston iTrader: (0)	Most countries have very strict rules about dB levels of the car, that's why they have the soft pad under the hood, a closed up air intake system and a subtle exhaust sound. Not to mention that most people do prefer a quiet car. __________________ zhpregistry.net - ZHP stats and free classifieds.
	Appreciate 0 Quote

01-10-2009, 12:03 PM	#20
gtrokin330 Brigadier General 150 Rep 3,865 Posts Drives: TT Join Date: Sep 2007 Location: LI iTrader: (7)	my 335 is extremely loud with the gold tee mod on a cold start. Imo the stock exhaust really is loud enough..
	Appreciate 0 Quote