ideal a/f ratio
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single digit dreamer
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Joined: Mar 2002
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From: omaha ne
ideal a/f ratio i just got a FJO wideband 02 set up. right now my ratio is around 10-1. i have a whipple and am running 7psi(non intercooled), any sugestions on what ratio i should shoot for? what about if i up the boost, should i still shoot for the same ratio?
thanks
thanks
Re: ideal a/f ratio Non-intercooled i'd keep it near 11:1. You're pushing alot of heat in like that, and the fuel helps cool things. You may have to reduce the timing a bit if you lean it out.
Upping the boost won't change were you want the A/F, but it may change were you actually are depending on your fueling.
Intercooled, i'm more keen on 12:1 to 12.5:1 with propper advance. I personally run 12.5:1 to 12.8:1 on the wideband.
If you're still running CAT's you'll wanna opt for a richer mixture. It'll keep the converter temps down and keep them from melting <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> If you've got an EGT gauge, i'd say tune to an A/F that keeps them below 1750°F and dial in the spark according to what it'll take. But if you're on WB only, keep it under 11.5:1 and you'll be safe.
Upping the boost won't change were you want the A/F, but it may change were you actually are depending on your fueling.
Intercooled, i'm more keen on 12:1 to 12.5:1 with propper advance. I personally run 12.5:1 to 12.8:1 on the wideband.
If you're still running CAT's you'll wanna opt for a richer mixture. It'll keep the converter temps down and keep them from melting <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> If you've got an EGT gauge, i'd say tune to an A/F that keeps them below 1750°F and dial in the spark according to what it'll take. But if you're on WB only, keep it under 11.5:1 and you'll be safe.
Thread Starter
single digit dreamer
iTrader: (6)
Joined: Mar 2002
Posts: 9,757
Likes: 4
From: omaha ne
Re: ideal a/f ratio sweet, thanks for the fast reply. i have no cats so i may shoot for the 11.5-1 number.
how about this senaro, 10psi with water injection, still 11.5-1? right now i am seeing around 15deg of advance, not sure where that would be if i were pushing 10spi.
and one more, any guess how much power i am missing out on being at 10-1 vs 11 or 11.5-1? think that will get me another 1/10? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
how about this senaro, 10psi with water injection, still 11.5-1? right now i am seeing around 15deg of advance, not sure where that would be if i were pushing 10spi.
and one more, any guess how much power i am missing out on being at 10-1 vs 11 or 11.5-1? think that will get me another 1/10? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
