Waht is cosidered a good A/F ratio?
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09-22-02, 01:19 PM
#8
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I merely stated that stoich is 14.7 ('cause thats what it is) in reality it is better to run a richer mixture (11 - 12 - 13) as insurance to prevent detonation... also depends on the octane of the gas.....
(btw, N/A rotaries run best at 83 octane!
)
so yeah, an 11 -12 would be rich, but good i think... ( dunno for sure tho...)
(btw, N/A rotaries run best at 83 octane!
)so yeah, an 11 -12 would be rich, but good i think... ( dunno for sure tho...)
09-22-02, 01:25 PM
#9
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Stoich is just a technical term in relation to all engines dynamics, not just rotaries. Basically, it just tells you the ideal ratio of fuel to air (at sea level). It is obviously better to run rich because the more lean you get, the more chance you have to detonate.
09-22-02, 10:08 PM
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Uhmm... the farther the number (A/F ratio) gets away from 14.7, the more rich/lean your car is. If it gets higher than 14.7 you are running lean, which can lead to detonation. If it gets significantly lower than 14, you a running rich (which leads to increased fuel consumption... and uhmm... short catalytic convertor life... and a safe engine... )
Does that help?
If not, what don't you understand specifically?
Does that help?
If not, what don't you understand specifically?
09-22-02, 10:19 PM
#12
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Originally posted by autocrash
Uhmm... the farther the number (A/F ratio) gets away from 14.7, the more rich/lean your car is. If it gets higher than 14.7 you are running lean, which can lead to detonation. If it gets significantly lower than 14, you a running rich (which leads to increased fuel consumption... and uhmm... short catalytic convertor life... and a safe engine... )
Does that help?
If not, what don't you understand specifically?
Uhmm... the farther the number (A/F ratio) gets away from 14.7, the more rich/lean your car is. If it gets higher than 14.7 you are running lean, which can lead to detonation. If it gets significantly lower than 14, you a running rich (which leads to increased fuel consumption... and uhmm... short catalytic convertor life... and a safe engine... )
Does that help?
If not, what don't you understand specifically?
turbo II's should be around 11.7 I think. but the N/A's run leaner. you need someone with N/A expensice to give you a number. because I don't know what it is...
what can you do with the dyno sheet? nothing really. you should have been adjusting it between runs. and left the dyno after it was at that number all across.
09-22-02, 10:45 PM
#13
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ok, here's what I wanted to know... after the dyno run, it will give me the A/F reading right? what A/F ratio should I be aiming for 1000 - 8000 RPM?
09-22-02, 11:53 PM
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Here is a highlight from Matt Leicher:
http://www.rx7turbo.com/afhighlight.htm
It is actually a Millivolt translation page but he mentions the A/F in there. It is different from everyone you talk to so keep it near 12:1 at full boost and go from there
Scott says 11.7:1 and others say 12.5:1 or whatever.
http://www.rx7turbo.com/afhighlight.htm
It is actually a Millivolt translation page but he mentions the A/F in there. It is different from everyone you talk to so keep it near 12:1 at full boost and go from there
Scott says 11.7:1 and others say 12.5:1 or whatever.
09-23-02, 12:00 AM
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Originally posted by Scott 89t2
that is not true... 14.7 is not the number between rich and lean... 14.7 is the number for the best emssions and gas millage. which is where most cars are under crusing. no car is near that under throttle.
turbo II's should be around 11.7 I think. but the N/A's run leaner. you need someone with N/A expensice to give you a number. because I don't know what it is...
what can you do with the dyno sheet? nothing really. you should have been adjusting it between runs. and left the dyno after it was at that number all across.
that is not true... 14.7 is not the number between rich and lean... 14.7 is the number for the best emssions and gas millage. which is where most cars are under crusing. no car is near that under throttle.
turbo II's should be around 11.7 I think. but the N/A's run leaner. you need someone with N/A expensice to give you a number. because I don't know what it is...
what can you do with the dyno sheet? nothing really. you should have been adjusting it between runs. and left the dyno after it was at that number all across.
Woohoo! I learned something new today... guess that means I can skip my classes, right?
Thanks, Scott, for the clarification/information... I don't know half of this stuff yet, but I'm trying!
09-23-02, 02:26 AM
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no.... probably around 12-13 under throttle.... but I have no idea on N/A's... 14.7 is where ANY car is at crusing.. when the A/F meter is going back and forth like crazy. that is the ECU keeping it at 14.7 you don't want to go any leaner under crusing.
09-23-02, 01:43 PM
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ok, correct me if i'm wrong... so the higher the number, the leaner the car is? so if it is higher and I wanted to richen it up on the S-AFC, I'll have to increase the percentage right?
09-23-02, 08:38 PM
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So, should I aim for a stright line on the graph then? I know we are not in a perfect world so this is impossible. But waht I wanted to know is should I stay at least between 12.5 to 12.8 across the RPM band?
09-23-02, 08:42 PM
#25
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Ideally, yes.
Since you've got access to a dyno, richen and lean a bit from the final settings to see if you gain any power.  Don't assume the readings from the sensor that they are spot-on.
-Ted
Since you've got access to a dyno, richen and lean a bit from the final settings to see if you gain any power.  Don't assume the readings from the sensor that they are spot-on.
-Ted