Optimum A/F Ratio When Under Boost?
06-29-2002, 06:18 PM
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Optimum A/F Ratio When Under Boost?
When under boost ( say, 12-15psi. in a built GSR engine ) what would be a good safe A/F ratio to shoot for to produce max. power? Thanks.
06-29-2002, 08:23 PM
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Re: Optimum A/F Ratio When Under Boost? (slowcivic)
You want to shoot for 11:1~12:1 for a compromise of good power/safety. If you want max power shoot for 12.5:1~13:1 but that is pushing it, very aggressive tuning.
06-30-2002, 12:04 PM
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Re: Optimum A/F Ratio When Under Boost? (boosted hybrid)
You want to shoot for 11:1~12:1 for a compromise of good power/safety. If you want max power shoot for 12.5:1~13:1 but that is pushing it, very aggressive tuning.
I've lived through a couple tanks of 87 in my lifetime
06-30-2002, 12:20 PM
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Re: Optimum A/F Ratio When Under Boost? (boosted hybrid)
A little OT, but what will the full rich on an autometer indicate? 12:1 or more? Less? I remember someone saying that the autometer a/f guage is real lean even at full rich display. I am going to tune it with my autometer for the time being and I am not going to be driving too aggressively. And I will be pushing like 5-7 psi on a d16a6 motor.
06-30-2002, 12:23 PM
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Re: Optimum A/F Ratio When Under Boost? (technine)
A little OT, but what will the full rich on an autometer indicate? 12:1 or more? Less? I remember someone saying that the autometer a/f guage is real lean even at full rich display. I am going to tune it with my autometer for the time being and I am not going to be driving too aggressively. And I will be pushing like 5-7 psi on a d16a6 motor.
art
06-30-2002, 03:42 PM
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Re: Optimum A/F Ratio When Under Boost? (Arturbo)
Thanks everyone! I will run 12.2 to 1 on 92 octaine Chevron pump gas and 12.5 to 1 on 101 octaine Union 76 Gas. Does that sound reasonable? Already have a Greddy A/F Guage and will be getting a Greddy EGT Guage soon.
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07-01-2002, 08:08 AM
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Re: Optimum A/F Ratio When Under Boost? (slowcivic)
Under Boost.. 12.49 will make the most power without compromising reliability.. And you REALLY NEED a wideband to read this.. DO NOT rely on any reading your OEM O2 sensor is putting out..
-Jason
-Jason
07-01-2002, 08:21 AM
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Re: Optimum A/F Ratio When Under Boost? (TurboCivicSi)
I really would like to Make My own Wideband O2 metering device. If only is was better with electronics. Someone on here could make some $$ if they would do this.
07-01-2002, 08:40 AM
#10
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Re: Optimum A/F Ratio When Under Boost? (89civic1.8T)
My car was tuned to 11.8-11.9 under 10psi for optimum power and reliability, esp. for a stock motor.
07-01-2002, 09:28 AM
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Re: Optimum A/F Ratio When Under Boost? (TorteX)
I think this question may have been beaten to death but can someone convert all of these air fuel ratios into exhaust gas temperatures, or is there maybe a chart that exists already on a website I don't know about
.Right now I'm having a really tough time still trying to figure my car out and the biggest problem is that I'm having mad fuel problems so I just need something thats gona help me out here and I'm sure all the other people around here would appriciate it....
Adi
07-01-2002, 10:21 AM
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Re: Optimum A/F Ratio When Under Boost? (newgsr)
you cannot convert a/f readings to EGT's because they both dictate different things. A/f is air fuel, as you would think, but EGT's are different, and can mean several things. A high egt with good a/f would tell me timing is too retarded, while a low egt with good a/f would mean ignition is too advanced. When I tune, I start with a nice, safe ignition value, and tune for a/f. Once that is safely tuned, then, based on EGT's, I'll advance or retard timing to get it to an area where max power is achieved along with safety. They are not the same thing, they are useful when used hand in hand.
07-01-2002, 10:33 AM
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Re: Optimum A/F Ratio When Under Boost? (VaporTrail)
you cannot convert a/f readings to EGT's because they both dictate different things. A/f is air fuel, as you would think, but EGT's are different, and can mean several things. A high egt with good a/f would tell me timing is too retarded, while a low egt with good a/f would mean ignition is too advanced. When I tune, I start with a nice, safe ignition value, and tune for a/f. Once that is safely tuned, then, based on EGT's, I'll advance or retard timing to get it to an area where max power is achieved along with safety. They are not the same thing, they are useful when used hand in hand.
So basicly either way you look at it a/f reading are just as important as egt readings but when you put the two together they work the best in aiding for a perfectly tuned car...
Thanks for the information VaporTrail I appriciate it a lot!!!
Adi
07-01-2002, 10:58 AM
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Re: Optimum A/F Ratio When Under Boost? (Bryson)
Say you have a fully built GSR Engine with a Compression Ratio of 9.0 to 1. You want to boost between 12 and 15psi. What A/F ratio should you set your standalone for WOT for Power and not sacrifice Safety? Thanks.
07-01-2002, 01:37 PM
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Re: Optimum A/F Ratio When Under Boost? (89civic1.8T)
Do a google search for "wideband O2 project." There are some Australians that have done all the work for you and it is very cheap (relatively). It even uses a stock Honda O2 sensor.
Ben
Ben
07-01-2002, 02:41 PM
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Re: Optimum A/F Ratio When Under Boost? (Bnjmn)
I have been reading there site. It's very informative. I really want to buy a pre-bult unit but they are not avalible right now and probably won't be for a while. I guess I will have to take a crash course in electronic.
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