exhaust tips never sooty
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Joined: Aug 2007
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Ed
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Race Director
Joined: Oct 2005
Posts: 14,999
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From: Bay Area Ca.
I never saw the graph or I should say the graph given me didn't contain the a/f mixture.
A reputable shop did the tune, rather not name now.
Car seems to run and behave fine, I get good mileage.
The clean tips do have me concerned though.
A reputable shop did the tune, rather not name now.
Car seems to run and behave fine, I get good mileage.
The clean tips do have me concerned though.
Burning Brakes
Joined: Feb 2007
Posts: 752
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From: Palm Harbor Florida
Uh-oh...
Burning Brakes
Joined: Apr 2006
Posts: 1,059
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From: Stokesdale NC
With the factory tune, my exhaust tips would be really sooty in a week. After the dyno tune, they stay much cleaner.
I guess the concern is running too lean and burning a piston. That is why the factory tune errs toward the rich side.
Other than installing a wideband O2 sensor, is there any way to tell if the motor is too lean?
I guess the concern is running too lean and burning a piston. That is why the factory tune errs toward the rich side.
Other than installing a wideband O2 sensor, is there any way to tell if the motor is too lean?
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Drifting
Joined: Apr 2006
Posts: 1,276
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From: Ambler Pa.
A/F ratio
Another side effect of too lean is knock on acceleration or under load. If you are not hearing knock or seeing knock retard, you are likely below the threshold of burning pistons. A wide band a/f sensor however is the safest way to know for sure.
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Joined: May 2003
Posts: 54
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From: Largo Florida
HI:
A perfectly tuned engine will not be black at the tips all the time. What I mean is if you engine that is normally aspirated ls2 or ls3 has a fuel mix of 12.5 to 13.0 for best power and fuel economy your tips should take a while to get alittle black. Now when you are hard on the engine and get into PE your tips may turn black if you stay near the factory settings or richer. Also spark plugs have alot to do with it. A hotter plug with give the combustion chamber higher temperatures. You can go one step cooler on the plug and fueling will change.
I tune PE so that fuel settings do not jump and if you are hard on the car your tips might begin to turn alittle white or clean if you are racing the car. Under normal driving slighty dark. Many turners have their own ideas on what the best fuel mixture is for the application at hand.
If you want to feel comfortable about your engines mixture then go with a cooler spark plug. Like a NGK TR6IX.
Chris
A perfectly tuned engine will not be black at the tips all the time. What I mean is if you engine that is normally aspirated ls2 or ls3 has a fuel mix of 12.5 to 13.0 for best power and fuel economy your tips should take a while to get alittle black. Now when you are hard on the engine and get into PE your tips may turn black if you stay near the factory settings or richer. Also spark plugs have alot to do with it. A hotter plug with give the combustion chamber higher temperatures. You can go one step cooler on the plug and fueling will change.
I tune PE so that fuel settings do not jump and if you are hard on the car your tips might begin to turn alittle white or clean if you are racing the car. Under normal driving slighty dark. Many turners have their own ideas on what the best fuel mixture is for the application at hand.
If you want to feel comfortable about your engines mixture then go with a cooler spark plug. Like a NGK TR6IX.
Chris
Advanced
Joined: Apr 2008
Posts: 52
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From: Sarasota Florida
[QUOTE=corvettedoctor;1566578232]HI:
A perfectly tuned engine will not be black at the tips all the time. What I mean is if you engine that is normally aspirated ls2 or ls3 has a fuel mix of 12.5 to 13.0 for best power and fuel economy your tips should take a while to get alittle black. Now when you are hard on the engine and get into PE your tips may turn black if you stay near the factory settings or richer. Also spark plugs have alot to do with it. A hotter plug with give the combustion chamber higher temperatures. You can go one step cooler on the plug and fueling will change.
I tune PE so that fuel settings do not jump and if you are hard on the car your tips might begin to turn alittle white or clean if you are racing the car. Under normal driving slighty dark. Many turners have their own ideas on what the best fuel mixture is for the application at hand.
If you want to feel comfortable about your engines mixture then go with a cooler spark plug. Like a NGK TR6IX.
Can you please explain how changing spark plug heat range affects fuel mixture?
A perfectly tuned engine will not be black at the tips all the time. What I mean is if you engine that is normally aspirated ls2 or ls3 has a fuel mix of 12.5 to 13.0 for best power and fuel economy your tips should take a while to get alittle black. Now when you are hard on the engine and get into PE your tips may turn black if you stay near the factory settings or richer. Also spark plugs have alot to do with it. A hotter plug with give the combustion chamber higher temperatures. You can go one step cooler on the plug and fueling will change.
I tune PE so that fuel settings do not jump and if you are hard on the car your tips might begin to turn alittle white or clean if you are racing the car. Under normal driving slighty dark. Many turners have their own ideas on what the best fuel mixture is for the application at hand.
If you want to feel comfortable about your engines mixture then go with a cooler spark plug. Like a NGK TR6IX.
Can you please explain how changing spark plug heat range affects fuel mixture?