Please explain exhaust terminology

jamze132 · 04-05-2012, 03:05 PM

A new exhaust seems to be pretty popular so can someone please explain, or point me in the right direction to figure out what the following terms mean?

cat back
axle back
test pipes
x pipes
connecting pipes

Can someone also explain why BMW didn't just put one of these nice after market exhausts on the car to begin with? Thanks!

bilal · 04-05-2012, 03:27 PM

sound. drone. and polution

tibra1 · 04-05-2012, 03:29 PM

Oh boy

JPatrick · 04-05-2012, 03:45 PM

Use of an internet search engine will yield plenty of results for each term.

BMW did put a nice exhaust system in their cars. People like to individualize their cars. There are also legal constraints as to what is allowed. That deters BMW, but not a lot of owners.

rjd598 · 04-05-2012, 03:52 PM

Quote:

Originally Posted by jamze132

A new exhaust seems to be pretty popular so can someone please explain, or point me in the right direction to figure out what the following terms mean?

cat back
axle back
test pipes
x pipes
connecting pipes

Can someone also explain why BMW didn't just put one of these nice after market exhausts on the car to begin with? Thanks!

simple search
http://m3forum.net/m3forum/showthread.php?t=370927
catbacks/axle backs=muffler and are the first part of the exhaust then comes the xpipe where cats and resonators are found

THE TECH · 04-05-2012, 04:15 PM

:

jamze132 · 04-05-2012, 06:06 PM

Quote:

Originally Posted by rjd598

simple search
http://m3forum.net/m3forum/showthread.php?t=370927
catbacks/axle backs=muffler and are the first part of the exhaust then comes the xpipe where cats and resonators are found

Thank you for your help.

drburton · 04-06-2012, 10:07 AM

I think these terms have some level of variable meaning but here is an attempt:

Cat Back - used to refer to exhaust replacement from the secondary cat to the back of the car.

Axle Back - just the rear exhaust that would then hookup with the stock x-pipe. Many seems to use cat back and axle back interchangeable, but in my mind they are a bit different.

X-pipe - goes from headers to 'axle back' exhaust. This goes under the main cabin of the car and includes both sets of cats (primary and secondary). Most people who replace the x-pipe are doing so to remove the cats and have less restriction.

Test pipes - Probably referring to the Turner test pipes. This is a solution to replace the primary cat without getting a whole new x-pipe. So you cut the stock x-pipe and insert the test pipes in place of the primary cats.

Hope this helps.

04-05-2012, 03:05 PM	#1
jamze132 Second Lieutenant 20 Rep 265 Posts Drives: 228i Join Date: Nov 2011 Location: San Antonio, TX iTrader: (0)	Please explain exhaust terminology - new guy here A new exhaust seems to be pretty popular so can someone please explain, or point me in the right direction to figure out what the following terms mean? cat back axle back test pipes x pipes connecting pipes Can someone also explain why BMW didn't just put one of these nice after market exhausts on the car to begin with? Thanks!
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04-05-2012, 03:27 PM	#2
bilal Enlisted Member 5 Rep 40 Posts Drives: e93 m3 Join Date: Jun 2010 Location: lebanon iTrader: (0)	sound. drone. and polution
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04-05-2012, 03:29 PM	#3
tibra1 Banned 127 Rep 6,773 Posts Drives: 2011 ZCP M3 - 2007 335i crashd Join Date: Apr 2009 Location: NYC iTrader: (4)	Oh boy
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04-05-2012, 03:45 PM	#4
JPatrick Private First Class 11 Rep 109 Posts Drives: 2011.5 E90 M3 Join Date: Nov 2010 Location: Seattle, WA iTrader: (0) Garage List 2011 BMW M3 [0.00] 1998 BMW M3 [0.00]	Use of an internet search engine will yield plenty of results for each term. BMW did put a nice exhaust system in their cars. People like to individualize their cars. There are also legal constraints as to what is allowed. That deters BMW, but not a lot of owners. __________________ 2011.5 E90 M3 - Space Gray/Extended Fox Red Leather/Sycamore Anthracite Trim, DCT, ZCP, everything except Moon Roof
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04-05-2012, 04:15 PM	#6
THE TECH BimmerPost Supporting Vendor 307 Rep 13,093 Posts Drives: BPMsport 2012 E92 M3 Join Date: Jun 2011 Location: Kansas iTrader: (45) Garage List 2013 Nissan GTR [0.00] 2019 Sierra Denali ... [0.00] 1999 Nissan Silvia [0.00] 1999 Nissan Skyline ... [0.00] 1998 Toyota Supra [0.00]	:
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04-06-2012, 10:07 AM	#8
drburton Lieutenant 116 Rep 468 Posts Drives: e92 M3 Alpine Join Date: Feb 2008 Location: Minneapolis iTrader: (3)	I think these terms have some level of variable meaning but here is an attempt: Cat Back - used to refer to exhaust replacement from the secondary cat to the back of the car. Axle Back - just the rear exhaust that would then hookup with the stock x-pipe. Many seems to use cat back and axle back interchangeable, but in my mind they are a bit different. X-pipe - goes from headers to 'axle back' exhaust. This goes under the main cabin of the car and includes both sets of cats (primary and secondary). Most people who replace the x-pipe are doing so to remove the cats and have less restriction. Test pipes - Probably referring to the Turner test pipes. This is a solution to replace the primary cat without getting a whole new x-pipe. So you cut the stock x-pipe and insert the test pipes in place of the primary cats. Hope this helps.
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