Drag Racing Tech
Sponsored by:
Sponsored by:

open headers?

Old Sep 13, 2010 | 01:07 PM
  #1  
BennyB's Avatar
Thread Starter
TECH Fanatic
15 Year Member
iTrader: (12)
 
Joined: Sep 2005
Posts: 1,079
Likes: 4
From: Omaha, NE
Default open headers?

i had a few questions as to my exhaust setup. I want to run the lightest and least amount of exhaust i can, but keep my 02's safe and reading accurately... or could i just do away with o2's run open loop and plug the bunge? The reason im asking is bc i have been running open loop for some time now plus it would save on money without having to buy new 02's. Im doing a cam swap so i will need a tune afterwards. I have been contemplating speed density tune, but dont have enough info or knowledge on the subject. Any replies, info or knowledge to help me out is much appreciated guys, thanks!
Reply
Old Sep 13, 2010 | 01:10 PM
  #2  
BennyB's Avatar
Thread Starter
TECH Fanatic
15 Year Member
iTrader: (12)
 
Joined: Sep 2005
Posts: 1,079
Likes: 4
From: Omaha, NE
Default

i was wondering about just running 14" turndowns right off the headers as an option also, if i decided to keep my 02's.
Reply
Old Sep 13, 2010 | 01:11 PM
  #3  
StreetSilverado's Avatar
9 Second Club
iTrader: (17)
 
Joined: Feb 2008
Posts: 1,146
Likes: 1
From: Texarkana, Texas
Default

If you want to run 02's and open headers just add about 12" pipe to the end of the header that way you won't get unmetered air from the 02.

This way even if you do go SD you can use a wideband accurately as well and just plug whatever extra 02 bungs you have.
Reply
Old Sep 13, 2010 | 01:16 PM
  #4  
BlackScreaminMachine's Avatar
Internet Mechanic
20 Year Member
iTrader: (17)
 
Joined: May 2005
Posts: 9,830
Likes: 2
From: Wallingford CT
Default

At that point at least. have the rear O2's turned off, have a bumg welded for a Wide Band as well. A 12" Turndown would be ideal.
Reply
Old Sep 13, 2010 | 01:16 PM
  #5  
BennyB's Avatar
Thread Starter
TECH Fanatic
15 Year Member
iTrader: (12)
 
Joined: Sep 2005
Posts: 1,079
Likes: 4
From: Omaha, NE
Default

Originally Posted by StreetSilverado
If you want to run 02's and open headers just add about 12" pipe to the end of the header that way you won't get unmetered air from the 02.

This way even if you do go SD you can use a wideband accurately as well and just plug whatever extra 02 bungs you have.
ok that was what i was wondering if the 14" turndown would be enough pipe. What about not running o2's and just running the turndowns in open loop? I dont understand exactly the benefits and or negatives on this.
Reply
Old Sep 13, 2010 | 01:17 PM
  #6  
BennyB's Avatar
Thread Starter
TECH Fanatic
15 Year Member
iTrader: (12)
 
Joined: Sep 2005
Posts: 1,079
Likes: 4
From: Omaha, NE
Default

Originally Posted by BlackScreaminMachine
At that point at least. have the rear O2's turned off, have a bumg welded for a Wide Band as well. A 12" Turndown would be ideal.
I had the rear o2's disabled when i had the car tuned last year so thats one problem out of the way.
Reply
Old Sep 13, 2010 | 02:13 PM
  #7  
StreetSilverado's Avatar
9 Second Club
iTrader: (17)
 
Joined: Feb 2008
Posts: 1,146
Likes: 1
From: Texarkana, Texas
Default

Originally Posted by BennyB
ok that was what i was wondering if the 14" turndown would be enough pipe. What about not running o2's and just running the turndowns in open loop? I dont understand exactly the benefits and or negatives on this.
Really depending on what you're using the car for. I'm assuming it's track only? I used to run open headers, but recently went back with a Y pipe and single Magnaflow. I did this to slow the car down just enough to run 7.0 Index though.
Reply
Old Sep 13, 2010 | 02:24 PM
  #8  
BennyB's Avatar
Thread Starter
TECH Fanatic
15 Year Member
iTrader: (12)
 
Joined: Sep 2005
Posts: 1,079
Likes: 4
From: Omaha, NE
Default

yeah pretty much track only getting her ready for next year
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-1

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-2

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-3

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-4

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-5

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-6

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-7

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-8

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-9

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
Old Sep 13, 2010 | 02:47 PM
  #9  
BlackScreaminMachine's Avatar
Internet Mechanic
20 Year Member
iTrader: (17)
 
Joined: May 2005
Posts: 9,830
Likes: 2
From: Wallingford CT
Default

Originally Posted by BennyB
ok that was what i was wondering if the 14" turndown would be enough pipe. What about not running o2's and just running the turndowns in open loop? I dont understand exactly the benefits and or negatives on this.
Open loop helps the car tune of the car. Really Emissions related. IF you have no requirement Speed Density Tune in Open loops is ideal and easier to do. I am not a Tuning guy but thats my understanding.

The length of tubing helps get the exhaust not to reverb on the body and behind the driver seat. Again IF not street use, then that is ideal.
Reply
Old Sep 13, 2010 | 06:33 PM
  #10  
Wicked94Z's Avatar
10 Second Club
iTrader: (26)
 
Joined: Jul 2005
Posts: 3,725
Likes: 1
From: Spokane, Wa
Default

what does speed density and open loop have to do with running open headers if you're running open loop throw the o2s away. It doesn't matter if you're running MAF, SD, Alpha-N or whatever.
Reply
Old Sep 14, 2010 | 01:32 AM
  #11  
BennyB's Avatar
Thread Starter
TECH Fanatic
15 Year Member
iTrader: (12)
 
Joined: Sep 2005
Posts: 1,079
Likes: 4
From: Omaha, NE
Default

Originally Posted by Wicked94Z
what does speed density and open loop have to do with running open headers if you're running open loop throw the o2s away. It doesn't matter if you're running MAF, SD, Alpha-N or whatever.
oh yeah i know that. Im just trying to look at my options here.... and if i ran open headers and bought new 02's without extensions on the collectors the 02's wouldnt read right, but what i think im going to end up doing is just run open loop and plug the bunges on the headers.
Reply
Old Sep 14, 2010 | 05:50 AM
  #12  
Wicked94Z's Avatar
10 Second Club
iTrader: (26)
 
Joined: Jul 2005
Posts: 3,725
Likes: 1
From: Spokane, Wa
Default

good call I've been OLSD for over a year now, it's great. Finally I'm going back to closed loop with the DFI stuff... but I'll probably just tune it in closed loop with the wideband, then go back to open loop again
Reply
Old Sep 14, 2010 | 09:18 AM
  #13  
JL ws-6's Avatar
Race your car!
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (50)
 
Joined: Mar 2004
Posts: 15,421
Likes: 19
Default

I messed around with different length pipe with a turndown when I ran my car on motor. I had it open loop tuned so all the o2's were off.

I found, that there was no difference running 16, 12 and 8 inches of pipe that was consistant enough, compared to running just the turndown off the end of the header fwiw.

As long as the o2's are off, ditch everything. I ran the turndown, just so the bottom of the car didn't get as dirty... if not for that I wouldn't have even bothered with that to be totally honest.
Reply
Old Sep 14, 2010 | 10:19 AM
  #14  
BennyB's Avatar
Thread Starter
TECH Fanatic
15 Year Member
iTrader: (12)
 
Joined: Sep 2005
Posts: 1,079
Likes: 4
From: Omaha, NE
Default

Originally Posted by JL ws-6
I messed around with different length pipe with a turndown when I ran my car on motor. I had it open loop tuned so all the o2's were off.

I found, that there was no difference running 16, 12 and 8 inches of pipe that was consistant enough, compared to running just the turndown off the end of the header fwiw.

As long as the o2's are off, ditch everything. I ran the turndown, just so the bottom of the car didn't get as dirty... if not for that I wouldn't have even bothered with that to be totally honest.
Ive been running open headers with no turndowns and i know exactly what your saying. The underside of my car is really dirty now and not only that, but i figured with the extra 14 inches of pipe and the turndown that the cabin noise and vibes might be a little less also.... im hoping anyway
Reply
Old Sep 14, 2010 | 12:25 PM
  #15  
JL ws-6's Avatar
Race your car!
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (50)
 
Joined: Mar 2004
Posts: 15,421
Likes: 19
Default

Honestly noise, unless you're running at a track with a regulation is the last thing I would worry about. Turndowns, will keep teh car alot cleaner, and that's about it. And, honestly are really about all you need. Open loop the car, get rid of the O2 sensor's completely, then you can crank the timing up and run race fuel to control the detonation, pick up some power at the same time.
Reply
Old Sep 14, 2010 | 12:32 PM
  #16  
BennyB's Avatar
Thread Starter
TECH Fanatic
15 Year Member
iTrader: (12)
 
Joined: Sep 2005
Posts: 1,079
Likes: 4
From: Omaha, NE
Default

Originally Posted by JL ws-6
Honestly noise, unless you're running at a track with a regulation is the last thing I would worry about. Turndowns, will keep teh car alot cleaner, and that's about it. And, honestly are really about all you need. Open loop the car, get rid of the O2 sensor's completely, then you can crank the timing up and run race fuel to control the detonation, pick up some power at the same time.
theres no regulation on noise so that wont be a problem. where can i find some plugs for the 02 bunges?
Reply
Old Sep 14, 2010 | 01:21 PM
  #17  
StreetSilverado's Avatar
9 Second Club
iTrader: (17)
 
Joined: Feb 2008
Posts: 1,146
Likes: 1
From: Texarkana, Texas
Default

Originally Posted by BennyB
theres no regulation on noise so that wont be a problem. where can i find some plugs for the 02 bunges?
Usually exhaust shops will have them laying around. If not I'm sure Pacesetter, Kooks, etc. can sell them.
Reply
Old Sep 14, 2010 | 06:46 PM
  #18  
BennyB's Avatar
Thread Starter
TECH Fanatic
15 Year Member
iTrader: (12)
 
Joined: Sep 2005
Posts: 1,079
Likes: 4
From: Omaha, NE
Default

ok cool. Thanks for all the help/ replies guys.
Reply
Old Sep 16, 2010 | 12:47 AM
  #19  
Powershift_98's Avatar
11 Second Club
iTrader: (1)
 
Joined: Aug 2010
Posts: 13
Likes: 0
From: Florence, KY
Default

Check autozone or whatever you have in your area for an Oil Drain Plug for a '83 toyota tercel. Dorman Part # 65220. Thats what I use and it works great!
Reply
Old Sep 16, 2010 | 06:10 AM
  #20  
JL ws-6's Avatar
Race your car!
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (50)
 
Joined: Mar 2004
Posts: 15,421
Likes: 19
Default

I've always just gotten an bolt the right thread from the local lowes/home depot bin and cut it short, so it wouldn't protrude into the pipe. Never had a problem capping an O2 bung that way. Or, leave a dead sensor in the hole, and just don't hook it up to anything.
Reply

Thread Tools
Search this Thread

All times are GMT -5. The time now is 02:42 PM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE