someone please explain air fuel ratio
Mar 22, 2006, 10:18 AM
#31
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Bro u have been more than helpfull with these questions i have asked. i want the light i just dont really like the look of it u know. people will think its a shift light(not that i really care what others think) when its a lot mroe than that.the gauge looks a lot better but we will see. i also found the aem uego for like 220 or something cheap like that, i just dont have an arc welder or mig welder so that would have to be done for me.
Originally Posted by joshd
Where did u find the KnockLite? I know Dan at Mach V sells them and would help you with the installation. I'm sure the product will come with install instructions ...
Mach V link
or you can just buy it direct from TurboXS
I'd be tempted to give Dan the business though ... I met him yesterday and he seems like a great guy.
As for the UEGO, no you do not need the stand alone EMS to make it work!
There are other options too, for example the Innovative stuff:
Innovative LC-1 controller with XD-16 gauge kit
Have fun!
Mach V link
or you can just buy it direct from TurboXS
I'd be tempted to give Dan the business though ... I met him yesterday and he seems like a great guy.
As for the UEGO, no you do not need the stand alone EMS to make it work!
There are other options too, for example the Innovative stuff:
Innovative LC-1 controller with XD-16 gauge kit
Have fun!
Dec 17, 2009, 01:18 PM
#32
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Hey guys, I'm trying to get into and understand the readings I get from my air fuel gauge. I've searched and this post is the best one I''ve found so I want to bring it back to life.
I have all basic bolts on along with kelfords 272s, my air fuel at idle is between 14.5 to 15.5 and then about 10.5 at WOT.
I'm trying to understand its meaning and whats too rich or too lean. I'm assuming Im running rich because I do smell the fuel when I first start her up.
Any help would be appreciated, thanks in advance guys!
I have all basic bolts on along with kelfords 272s, my air fuel at idle is between 14.5 to 15.5 and then about 10.5 at WOT.
I'm trying to understand its meaning and whats too rich or too lean. I'm assuming Im running rich because I do smell the fuel when I first start her up.
Any help would be appreciated, thanks in advance guys!
Dec 17, 2009, 01:55 PM
#33
Hey guys, I'm trying to get into and understand the readings I get from my air fuel gauge. I've searched and this post is the best one I''ve found so I want to bring it back to life.
I have all basic bolts on along with kelfords 272s, my air fuel at idle is between 14.5 to 15.5 and then about 10.5 at WOT.
I'm trying to understand its meaning and whats too rich or too lean. I'm assuming Im running rich because I do smell the fuel when I first start her up.
Any help would be appreciated, thanks in advance guys!
I have all basic bolts on along with kelfords 272s, my air fuel at idle is between 14.5 to 15.5 and then about 10.5 at WOT.
I'm trying to understand its meaning and whats too rich or too lean. I'm assuming Im running rich because I do smell the fuel when I first start her up.
Any help would be appreciated, thanks in advance guys!
14.7 is the number where the fuel and air are at a ratio where no extra fuel or air is left over.
Dec 17, 2009, 02:05 PM
#34
Hey guys, I'm trying to get into and understand the readings I get from my air fuel gauge. I've searched and this post is the best one I''ve found so I want to bring it back to life.
I have all basic bolts on along with kelfords 272s, my air fuel at idle is between 14.5 to 15.5 and then about 10.5 at WOT.
I'm trying to understand its meaning and whats too rich or too lean. I'm assuming Im running rich because I do smell the fuel when I first start her up.
Any help would be appreciated, thanks in advance guys!
I have all basic bolts on along with kelfords 272s, my air fuel at idle is between 14.5 to 15.5 and then about 10.5 at WOT.
I'm trying to understand its meaning and whats too rich or too lean. I'm assuming Im running rich because I do smell the fuel when I first start her up.
Any help would be appreciated, thanks in advance guys!
AFR which most gauges use and is usually the easiest to understand has a broad scale from 7:1 all the way up to 26:1. Obviously neither one are good for using in a engine.
14.7:1 is the optimal AFR for best emissions and fuel economy.
This is why your car idles where it does, for the lowest emissions and fuel consumption.
The better range for fuel economy comes form 15.2-15.7, this in turn though will affect your emissions(greater output).
In terms of performance the best power is achieved at the 12.5 +/- .2 AFR. Now keep in mind gas is a temperature control. So while running this "lean" generates more heat then is desired in high boost applications it can also create detonation(knock). Both can lead to part failures in the motor as well as the turbo itself.
In this instance depending on air cooling mods and efficiency we target a richer AFR anywhere between 11.8-10.9 AFR. This allows the excess gas to cool the exhaust temperatures down and prevent things from melting or detonating.
Now if your seeing 10.5 in boost that would be a little overly rich. Now depending on your type of enviroment, IC efficiency, and driving conditions you'll want to richen it up a bit. At least a full half point. Of course if this were e85 or race gas fueling is done a little differently.
As far as smelling gas well that will happen when you first start the car up and its cold.
Dec 17, 2009, 06:12 PM
#36
First off I hope you didn't read too much of this thread because its cluttered with misinformation.
AFR which most gauges use and is usually the easiest to understand has a broad scale from 7:1 all the way up to 26:1. Obviously neither one are good for using in a engine.
14.7:1 is the optimal AFR for best emissions and fuel economy.
This is why your car idles where it does, for the lowest emissions and fuel consumption.
The better range for fuel economy comes form 15.2-15.7, this in turn though will affect your emissions(greater output).
In terms of performance the best power is achieved at the 12.5 +/- .2 AFR. Now keep in mind gas is a temperature control. So while running this "lean" generates more heat then is desired in high boost applications it can also create detonation(knock). Both can lead to part failures in the motor as well as the turbo itself.
In this instance depending on air cooling mods and efficiency we target a richer AFR anywhere between 11.8-10.9 AFR. This allows the excess gas to cool the exhaust temperatures down and prevent things from melting or detonating.
Now if your seeing 10.5 in boost that would be a little overly rich. Now depending on your type of enviroment, IC efficiency, and driving conditions you'll want to richen it up a bit. At least a full half point. Of course if this were e85 or race gas fueling is done a little differently.
As far as smelling gas well that will happen when you first start the car up and its cold.
AFR which most gauges use and is usually the easiest to understand has a broad scale from 7:1 all the way up to 26:1. Obviously neither one are good for using in a engine.
14.7:1 is the optimal AFR for best emissions and fuel economy.
This is why your car idles where it does, for the lowest emissions and fuel consumption.
The better range for fuel economy comes form 15.2-15.7, this in turn though will affect your emissions(greater output).
In terms of performance the best power is achieved at the 12.5 +/- .2 AFR. Now keep in mind gas is a temperature control. So while running this "lean" generates more heat then is desired in high boost applications it can also create detonation(knock). Both can lead to part failures in the motor as well as the turbo itself.
In this instance depending on air cooling mods and efficiency we target a richer AFR anywhere between 11.8-10.9 AFR. This allows the excess gas to cool the exhaust temperatures down and prevent things from melting or detonating.
Now if your seeing 10.5 in boost that would be a little overly rich. Now depending on your type of enviroment, IC efficiency, and driving conditions you'll want to richen it up a bit. At least a full half point. Of course if this were e85 or race gas fueling is done a little differently.
As far as smelling gas well that will happen when you first start the car up and its cold.
Thank you, thank you so much for writting all of this so I didn't have to, saved me a lot of time
There is a lot of misunderstood info in this thread, this is basically spot on....
There is such things as too rich, just the same as too lean. Motor to motor is different, some will allow leaner burns than others, the key is the fuel mixture that makes the most power and keeps you safe. keep in mind, alcohols do not have the same stoich as gasoline, so using gasoline 02 sensors are not suitable... you'll need to understand lambda.
Klaus explains too rich pretty well...
http://www.034motorsport.com/article...rticles_id=130
Dec 17, 2009, 06:41 PM
#37
something that i haven't seen noticed in this thread is timing.
if you add more fuel (running rich) you have to run more timing because the flame front moves slower through the mixture.
If you run it "lean" (say 12.5:1) then you can make the same, if not more power, with less timing because the flame front moves faster.
obviously the design of the combustion chamber makes a difference too, squish areas etc.
if you add more fuel (running rich) you have to run more timing because the flame front moves slower through the mixture.
If you run it "lean" (say 12.5:1) then you can make the same, if not more power, with less timing because the flame front moves faster.
obviously the design of the combustion chamber makes a difference too, squish areas etc.
Dec 17, 2009, 09:37 PM
#40
Not necessarily bad, but detrimental to power. I have never seen a car wash down cylinders but I have seen them sputter and cough and smoke (I assume its doing the same thing).
Some helpful data to clarify alot of comments in this thread-
Stoich is related to efficiency and should NEVER be confused with what makes best power.
You have max power rich and max power lean (aka RBT and LBT), see attached links:
http://en.wikipedia.org/wiki/Air-fuel_ratio
http://www.bristoldyno.com/tech/airfuel.htm
http://www.max-boost.co.uk/max-boost...20metering.htm
Keep in mind we can use these values for Ethanol with a gasoline calibrated WB (this is common practice in fact) so you can judge for yourself what RBT / LBT relationship you want to run. Keep in mind EGT follows AFR as well.
Some helpful data to clarify alot of comments in this thread-
Stoich is related to efficiency and should NEVER be confused with what makes best power.
You have max power rich and max power lean (aka RBT and LBT), see attached links:
http://en.wikipedia.org/wiki/Air-fuel_ratio
http://www.bristoldyno.com/tech/airfuel.htm
http://www.max-boost.co.uk/max-boost...20metering.htm
Keep in mind we can use these values for Ethanol with a gasoline calibrated WB (this is common practice in fact) so you can judge for yourself what RBT / LBT relationship you want to run. Keep in mind EGT follows AFR as well.
Dec 17, 2009, 10:31 PM
#44
Originally Posted by RSMike
something that i haven't seen noticed in this thread is timing.
if you add more fuel (running rich) you have to run more timing because the flame front moves slower through the mixture.
If you run it "lean" (say 12.5:1) then you can make the same, if not more power, with less timing because the flame front moves faster.
obviously the design of the combustion chamber makes a difference too, squish areas etc.
if you add more fuel (running rich) you have to run more timing because the flame front moves slower through the mixture.
If you run it "lean" (say 12.5:1) then you can make the same, if not more power, with less timing because the flame front moves faster.
obviously the design of the combustion chamber makes a difference too, squish areas etc.
However... my old turbo Neon (2.4L) made more power at 11.8:1 than it did at 11.2:1.
Our FSAE car loved it at 13.5:1... that's a whole other topic
So I won't say that there is a garuanteed success with going leaner...or richer. It really depends on the engine and the components. The best way to determine what the best AFR is.... is to actually tune the car and use the dyno as the tool it is.
Last edited by R/TErnie; Dec 17, 2009 at 10:33 PM.
