Will adding headers make you A/F mixture richer or leaner?
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Melting Slicks
Joined: Jun 2000
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From: Dallas / Fort Worth, Texas Texas
Will adding headers make you A/F mixture richer or leaner?
I'm adding a set of Belanger Long Tube Headers and would like to know if the addition of headers on a lightly modded A4 vette will make it run richer or leaner .. it runs too lean now ..
:cool: :cheers: :smash: :seeya
:cool: :cheers: :smash: :seeya
Le Mans Master
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Re: Will adding headers make you A/F mixture richer or leaner? (Don&Kelly)
I am extremely interested to hear answers on this one too. Fortunately, mine is a 98, so an adjustible fuel regulator can help.
Melting Slicks
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From: Frisco TX
Re: Will adding headers make you A/F mixture richer or leaner? (chuckster)
Richer...
It has to do with the scavenging effect pulling unburnt fuel from the cylinders...
It has to do with the scavenging effect pulling unburnt fuel from the cylinders...
I have seen this to be true on several occasions.. :seeya
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Re: Will adding headers make you A/F mixture richer or leaner? (bparker)
In my opinion long tube headers will usually make your car run more LEAN at part throttle, and more RICH at Wide Open Throttle. This has to do with the PCM adding extra fuel added in (LTRIMs) at part throttle having an opposite effect on your WOT air/fuel ratio.
Melting Slicks
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Re: Will adding headers make you A/F mixture richer or leaner? (MattG)
In my opinion long tube headers will usually make your car run more LEAN at part throttle, and more RICH at Wide Open Throttle. This has to do with the PCM adding extra fuel added in (LTRIMs) at part throttle having an opposite effect on your WOT air/fuel ratio.
I just ordered my catbacks and now I am looking for a long tubes, cats, and x-pipe setup.... :D
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Melting Slicks
Joined: Mar 2002
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From: Tx
Re: Will adding headers make you A/F mixture richer or leaner? (SideStep)
Tuning! You could use a MAFT or LS1-edit.... You usually just need to get those part throttle fuel trims to read a little on the negative side.
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Re: Will adding headers make you A/F mixture richer or leaner? (SideStep)
So what is the best fix for this :confused:
I just ordered my catbacks and now I am looking for a long tubes, cats, and x-pipe setup.... :D
I just ordered my catbacks and now I am looking for a long tubes, cats, and x-pipe setup.... :D
Drifting
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Re: Will adding headers make you A/F mixture richer or leaner? (MattG)
Matt,
i just put on the FLP long tubes with high flow cats and x-pipe on the Z,
the car seems to be running great.
how can you tell if it's rich or lean and is there any potential for damage
occuring?
mike
i just put on the FLP long tubes with high flow cats and x-pipe on the Z,
the car seems to be running great.
how can you tell if it's rich or lean and is there any potential for damage
occuring?
mike
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Re: Will adding headers make you A/F mixture richer or leaner? (35069)
Matt,
i just put on the FLP long tubes with high flow cats and x-pipe on the Z,
the car seems to be running great.
how can you tell if it's rich or lean and is there any potential for damage
occuring?
mike
i just put on the FLP long tubes with high flow cats and x-pipe on the Z,
the car seems to be running great.
how can you tell if it's rich or lean and is there any potential for damage
occuring?
mike
Race Director
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From: Palm City Florida
Re: Will adding headers make you A/F mixture richer or leaner? (MattG)
In my opinion long tube headers will usually make your car run more LEAN at part throttle, and more RICH at Wide Open Throttle. This has to do with the PCM adding extra fuel added in (LTRIMs) at part throttle having an opposite effect on your WOT air/fuel ratio.
Pro
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From: St. Louis MO
Re: Will adding headers make you A/F mixture richer or leaner? (MattG)
In my opinion long tube headers will usually make your car run more LEAN at part throttle, and more RICH at Wide Open Throttle. This has to do with the PCM adding extra fuel added in (LTRIMs) at part throttle having an opposite effect on your WOT air/fuel ratio.
Melting Slicks
Joined: Mar 2001
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From: El Paso TX
Re: Will adding headers make you A/F mixture richer or leaner? (415cid Goose)
When I added headers I was lean. Richened up the mix with a MAFT and picked up about 10hp/10tq. Probably could dial it in a little better with LS1 Edit. :cheers:
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Re: Will adding headers make you A/F mixture richer or leaner? (415cid Goose)
99% of the time.........
Gee, funny that you lean it out wether its EFI/TBI/TPI/DPI/EIEIOI or a carbed SBC.........funny how exhaust system changes effect ANY engine :crazy: just like air intake. After all, its just a big air pump
Must be that Engineering shi# :lol:
Le Mans Master
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Re: Will adding headers make you A/F mixture richer or leaner? (ALLTHROTTLE&NOBOTTLE)
If people look at their A/F on a Dyno after the install of headers, it is more rich than before the headers.. The problem is, getting them to understand how leaning out Part Throttle can richen Wide Open Throttle. People have to understand how LTRIMs work, and how the value of the WOT LTRIM being positive from running lean at Part Throttle causes the PCM to add in TOO much fuel at WOT because it gets added in with the Power Enrichment mode amount.
Safety Car
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Re: Will adding headers make you A/F mixture richer or leaner? (MattG)
If people look at their A/F on a Dyno after the install of headers, it is more rich than before the headers.. The problem is, getting them to understand how leaning out Part Throttle can richen Wide Open Throttle. People have to understand how LTRIMs work, and how the value of the WOT LTRIM being positive from running lean at Part Throttle causes the PCM to add in TOO much fuel at WOT because it gets added in with the Power Enrichment mode amount.
Melting Slicks
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From: Frisco TX
Re: Will adding headers make you A/F mixture richer or leaner? (MattG)
Dang MattG - I bet it took you a while to finger all this out eh? I would have never thought that headers would make you run lean under part throttle.. :crazy:
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Re: Will adding headers make you A/F mixture richer or leaner? (MattG)
Matt,
Guess ya have tuned more than a couple of cars eh?;)
As with any system, it is give & take :yesnod:
I play with flow calcs & RTD info all the time here at work, fuel injection is no different.
Tweak in little steps, ONE STEP AT A TIME.
Each car is different, we are not in a perfect tuning world...........but close enough.
Once I put on my FLPs, I will see where I am at.
I have lots of pre-install data to go by.
Might be good to go out of the box! :cheers:
Guess ya have tuned more than a couple of cars eh?;)
As with any system, it is give & take :yesnod:
I play with flow calcs & RTD info all the time here at work, fuel injection is no different.
Tweak in little steps, ONE STEP AT A TIME.
Each car is different, we are not in a perfect tuning world...........but close enough.
Once I put on my FLPs, I will see where I am at.
I have lots of pre-install data to go by.
Might be good to go out of the box! :cheers: