Air Fuel Ratio

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Jul 1, 2006 | 10:13 PM

#61

JimS

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From: Galesburg Il

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Jul 25, 2009 | 05:24 PM

#62

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Jul 25, 2009 | 09:32 PM

#63

mcfarlnd

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From: DFW

i had a discussion about the afr's for nitrous a while back and found that if your running in the 11s ,spraying, it is unnecessary to be that rich. i have leaned up mine and can vouch for the dependability and power increase. here is the thread; https://www.performancetrucks.net/fo...&highlight=afr

Jul 27, 2009 | 10:59 AM

#64

ForcedTQ

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From: Northern CA

Quote:

Originally Posted by 1SlowHoe

So meth alone allowed you to add 8* of timing? All while keeping the safe AFR? Any idea what the power increase was from that? Dyno before and after meth?

I would think that the addition of the meth cooled the intake charge to allow the addition of timing, as well as made the A/F ratio a bit richer. The actual power increase probably came from the fact that timing could be advanced to the point where the peak cylinder pressure happened at the optimum time relative to the degrees of rotation of the crank.

Mis-read your question, you wanted to see his power figures before and after. I just typed down why.

Jan 26, 2018 | 04:25 AM

#65

Capt-Kirk

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I am LSA supercharger with 10.5 PSI or so cruising I read 14.6 and 10.9 deep in boost with no load. on a stock 5.3L 65K miles
What AF should I aim for towing from 1800 ft above sea lever to 12,000 feet? in 110 degree summer heat?
I live in phoenix and Camp in the Flagstaff 2 weekends a month in the summer.
what about timing? 18* or higher on 91 octane?

Jan 26, 2018 | 06:39 PM

#66

FFDP

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10.9 is rich but safe. Going lean to 11.3-11.5ish would likely make more power.

Timing is a complete toss up but the lower the better for extended periods of boost. Anywhere from 13-16 seems to do alright but this is where watching for knock and stuff like that is key.

Dec 7, 2023 | 06:08 PM

#67

Adam Schneider

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From: Eastern North Carolina

Quote:

Originally Posted by TURBHOE

It has been found experimentally that the ideal mixture, the one where these two elements are perfectly balanced is 14.7:1 by weight, i.e. 14.7grams of air and 1gram of fuel. Or 14.7lbs of air and 1lb of fuel. This is called 'stoichiometric', meaning in Greek measure of the elements.

here read this it may help i read it its long but you might learn something lol.

stoichiometric 14.7 to 1 afr.
Also it should be mentioned that it is also equal to 100 kpa.