Dumb Quesiton: Why do they have bends on exhaust pipes, maybe better performance?

Thread Tools
 
Search this Thread
 
Old Jan 12, 2005 | 12:12 PM
  #1  
xicema17x's Avatar
Thread Starter
Registered User
iTrader: (22)
 
Joined: Jul 2004
Posts: 865
From: CA
Car Info: 71 rb26 240z
Red face Dumb Quesiton: Why do they have bends on exhaust pipes, maybe better performance?

I was wondering why there are bends on exhaust pipings, cant they just make it straight for more performance or do the bends also help performance? Dumb question, but it was kinda bugging me.
Old Jan 12, 2005 | 12:55 PM
  #2  
stg2lgcy00's Avatar
VIP Member
iTrader: (23)
 
Joined: Sep 2003
Posts: 4,969
From: Fremont
Car Info: 1999 2.5RS / 2004 Forester X
Most cars have the bends since the muffler is designed to mount on the left or right side of the car. Not just that but there's everything under the car that the exhaust has to avoid like the tranny, driveshaft, rear diff, rear suspension arms, swaybar ect.. I mean technically I guess you could put a literally straight turboback on the car but it would be wayy too low and have to be mounted right under your license plate... great place for cops to see your expired registration and illegal exhaust at the same time hahah.
Old Jan 12, 2005 | 12:55 PM
  #3  
nic3krnnamja83's Avatar
VIP Member
iTrader: (8)
 
Joined: Feb 2003
Posts: 4,755
From: Santa Rosa, CA
Car Info: 02 Subaru WRX w/ JDM Spec C
this question would be better suited in the dump

but mandrel bends cause u would not be able to straight pipe considering there are components in the way
Old Jan 12, 2005 | 02:20 PM
  #4  
Zoeb2s's Avatar
I <3 White Girls
iTrader: (38)
 
Joined: Nov 2002
Posts: 26,491
From: Danville, CA
Car Info: E92 M3, E70, F32, E21
Originally Posted by nic3krnnamja83
this question would be better suited in the dump

but mandrel bends cause u would not be able to straight pipe considering there are components in the way
Are you making fun of the dumpster?
Old Jan 12, 2005 | 02:52 PM
  #5  
nic3krnnamja83's Avatar
VIP Member
iTrader: (8)
 
Joined: Feb 2003
Posts: 4,755
From: Santa Rosa, CA
Car Info: 02 Subaru WRX w/ JDM Spec C
lol zoeb no :hail: dumpster mod
Old Jan 12, 2005 | 04:05 PM
  #6  
earlyapex's Avatar
Registered User
iTrader: (3)
 
Joined: Dec 2004
Posts: 582
From: I wuv imprezeR with all muh heartz. CareBearZ fur
Car Info: 05' Evo MR w/E85 - 10' Ralliart Sportback w/E85
I'm biting my lip.

doh.
Old Jan 12, 2005 | 05:56 PM
  #7  
xicema17x's Avatar
Thread Starter
Registered User
iTrader: (22)
 
Joined: Jul 2004
Posts: 865
From: CA
Car Info: 71 rb26 240z
Would getting like a turboxs downpipe and making a straight pipe from the end of the downpipe to the axle work? If that works, i might do that instead.
Old Jan 12, 2005 | 06:07 PM
  #8  
cleofis's Avatar
Registered User
iTrader: (11)
 
Joined: Jan 2004
Posts: 624
From: out of body
Car Info: 2001 2.5rs
like..no muffler you mean?

the reason for bends is, a: to menouver(sp?) around components of the car like the rear axle, control arms, sway bar, etc. and b: better flow. with mandrel bends instead of dented bends or straight pipe welds at angles, the air flows smoother like a current instead of jabbing at the angles thus reducing air flow.

i love run-on sentences.
Old Jan 12, 2005 | 07:38 PM
  #9  
xicema17x's Avatar
Thread Starter
Registered User
iTrader: (22)
 
Joined: Jul 2004
Posts: 865
From: CA
Car Info: 71 rb26 240z
Originally Posted by cleofis
like..no muffler you mean?

the reason for bends is, a: to menouver(sp?) around components of the car like the rear axle, control arms, sway bar, etc. and b: better flow. with mandrel bends instead of dented bends or straight pipe welds at angles, the air flows smoother like a current instead of jabbing at the angles thus reducing air flow.

i love run-on sentences.
No there is a muffler, but the straight pipe goes from the end of the downpipe to the muffler. Would I get better performance from doing that, or should i just go with a dowpipe like helix, where the 3rd cat is combined with the downpipe?
Old Jan 12, 2005 | 07:41 PM
  #10  
Wingless Wonder's Avatar
Registered User
iTrader: (7)
 
Joined: Dec 2002
Posts: 10,029
From: Sacramento CA
Car Info: 02 Impreza WRX sedan
Origami posted by xicema17x
I was wondering why there are bends on exhaust pipings, cant they just make it straight for more performance or do the bends also help performance?
The factory exhaust system is a compromise for fit, noise control, ground clearance, and cost. From the downpipe back it may be possible to use darned near straight pipe with minimal bends but you will probably lose ground clearance or find interference with the rear suspension. Do not terminate the exhaust system underneath the car for street use - run it all the way to the rear bumper like the factory does. The fumes will rise into the passenger compartment, or through the windows or the ventilation system.

Exhaust gasses should flow in a straight line for the least amount of backpressure. The traditional rule of thumb is that introducing a 90° bend in a length of tubing adds the same amount of restriction as 10 additional feet of the same diameter tubing. Two 45° bends separated by straight pipe create less restriction than a single 90° bend of the same radius.

--
0==WW==0
"…axles of evil…" - george w. bush
Old Jan 12, 2005 | 07:50 PM
  #11  
cleofis's Avatar
Registered User
iTrader: (11)
 
Joined: Jan 2004
Posts: 624
From: out of body
Car Info: 2001 2.5rs
you will have hp gains, but your car will be loud as hell. i would run a high flow cat + resonator + a good muffler in compliance to a "straight pipe"
Old Jan 12, 2005 | 09:03 PM
  #12  
WRX Rush's Avatar
VIP Member
iTrader: (7)
 
Joined: Jul 2003
Posts: 1,639
From: Hwy 39, CA
Car Info: Stage 4+ Bugeye
If you have the MPJ flange or something like it you can attach a 3 inch dump pipe towards the ground to that, it is fun to run around for a few days with no exhaust pipes on at all.

Rush
Old Jan 13, 2005 | 09:43 PM
  #13  
thebankman's Avatar
VIP Member
iTrader: (7)
 
Joined: Nov 2002
Posts: 1,819
From: Bay Area
Car Info: subaru
a perfectly-designed car would be made to accomodate a straight exhaust pipe, but most get by with a couple bends here and there.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
dchoi23
Wheel & Tire
6
Jul 22, 2009 01:58 PM
Rivers
Sacramento & Reno
164
Sep 15, 2008 11:44 PM
T-Will
Sacramento & Reno
112
Sep 10, 2008 11:38 PM
Choku Dori
Photoshop & Photography
3
Jul 14, 2008 07:26 PM
romoranger
Tri-State
0
May 6, 2003 08:40 PM




All times are GMT -7. The time now is 05:44 PM.