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Old 03-01-2006, 10:04 PM
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Default What's your target afr?

Hi,
I've started tuning my car and I just wanted to see what air/fuel ratios everyone is targeting. I'd like to take the discssion one step past getting a wideband and learning what to do next.

Please include whether your target afr are for street or track and conservative or agressive. Personally, I'm interested in a conservative daily driven tune.

This is what I'm targetting for:
13.5 AFR while NA.
12.5 AFR from 0psi to 3psi.
12.25 AFR from 3psi to 5psi.
12.0 AFR from 5psi to 7psi.
11.5 AFR from 7psi to 10psi.

So to all you tuners out there, please lend your knowledge and school me on the subject.

Thanks!
Old 03-01-2006, 11:56 PM
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Default Re: What's your target afr? (asianspeed)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by asianspeed &raquo;</TD></TR><TR><TD CLASS="quote">Hi,

This is what I'm targetting for:
13.5 AFR while NA.
12.5 AFR from 0psi to 3psi.
12.25 AFR from 3psi to 5psi.
12.0 AFR from 5psi to 7psi.
11.5 AFR from 7psi to 10psi.
Thanks!</TD></TR></TABLE>

You got the right idea. Don't forget, for cruise you can shoot for mid 15-14s.
Old 03-02-2006, 03:47 AM
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Default Re: What's your target afr? (sohc_turd)

yea you are pretty on point with those ratios. i was running my car at 12.2-11.8 up through 11 psi, with rather conservative timing.

vacuum a/f should be roughly as follows

15:1 @idle, or more than 20"
14.5:1 or so up to around 10"
i dont like to dip into the 13's until 7-8"
from 2" to 0", thats when the 13-13.5 a/f should be.

boost transition right about 12.8-13:1, then cut into the boost a/f's you have listed.
Old 03-02-2006, 06:45 AM
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Default Re: What's your target afr? (blackeg)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blackeg &raquo;</TD></TR><TR><TD CLASS="quote">yea you are pretty on point with those ratios. i was running my car at 12.2-11.8 up through 11 psi, with rather conservative timing.

vacuum a/f should be roughly as follows

15:1 @idle, or more than 20"
14.5:1 or so up to around 10"
i dont like to dip into the 13's until 7-8"
from 2" to 0", thats when the 13-13.5 a/f should be.

boost transition right about 12.8-13:1, then cut into the boost a/f's you have listed.</TD></TR></TABLE>

Yep yep


Not to be a dick asianspeed, but why are you posting this when yu already had that other thread on vaccum AFR's? Are you going to post one on full boost AFR's now? AFR's really don't make alot of power unless you're a good point or point and a half off. Timing is where the real power is.
Old 03-02-2006, 08:26 AM
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Default Re: What's your target afr? (adseguy)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by adseguy &raquo;</TD></TR><TR><TD CLASS="quote">

Yep yep


Not to be a dick asianspeed, but why are you posting this when yu already had that other thread on vaccum AFR's? Are you going to post one on full boost AFR's now? AFR's really don't make alot of power unless you're a good point or point and a half off. Timing is where the real power is. </TD></TR></TABLE>

My other post wasn't about vaccum afr's, it was asking help with effective steps toward tuning. This question is geared toward what those steps should be aiming for. Does that make sense? I'm learning about techniques to tune...but I still wasn't quite clear what I should be aiming for. I could street tune with a wideband all day....but if I'm not targetting the correct afr then what good is tuning it. I tried searching for a definitive answer, but came up unsuccessful. What I have noticed is that people are targetting anywhere from 12.5 to 11.5 afr, but I know that everyones goals are different. I wasn't sure what a conservative afr is and what an aggressive afr is....and at what point I should be targetting that afr.

I'm just trying to learn and thanks for helping me!

While we're on the subject, I was curious about tuning with uberdata, I'd love it if you or anyone else could advise. The fuel maps are in rpms and in/Hg, and you can change the range of the rpms under the rpm low/rpm high rev limits tab...and you can change the range of the in/Hg under map scalar in the Misc tab. Correct? So this is what I'm wondering. When I'm tuning can I change the ranges back and forth without loosing information? For example, let's say I do a run and between 5,000 and 5,300 rpms my afr is 10.5 and I'd like it to be 12.0. But the rpm range in the fuel map only allows me to adjust the fuel at 5,000 and then at 6,000 rpms. But from 5,300 and 6,000 rpms my afr is at the desired 12.0. To remidy this can I go to the rev limits tab and adjust the ranges of the rpms in the fuel map to display 5,000 and 5,300. Then when I'm done tuning this rpm range, then I can revert the rpm low values back to their original 5,000 and 6,000? I hope this makes sense, let me know if it doesn't.
Old 03-02-2006, 08:43 AM
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Default Re: What's your target afr? (asianspeed)

I see what you're saying. This is where 2d or 3-d line graphs come in (look at the lower tabs) As long as everything is fairly linear then you won't "dip" or "spike" anywhere in the graph. Remember the ECU also interpolates the values meaning the cell at 5000rpm and 14in/hg you will be reading the 4 cells next to it too and the ECU will take the average. That's why I saif earlier not to worry about adjusting one cell at a time, but instead adjust entire rows or columns at a time. If you don't get this, you will once you start on your own. . This also explains why I was saying to go from the high 13's to around high 12's INTO boost transition because you'll have a better fuel "curve". Nothing should ever be drastic when looking at 2-D graphs. I can get in further like if you REALLY nail your AFR's you'll actually see where peak torque is because fueling needs MATCH torque graphs....anyway I'm going off on a tangent as usual. Just use what we've been saying so far and you'll be fine. Like I said, learn more about ignition fueling is really easy
Old 03-02-2006, 09:03 AM
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Default Re: What's your target afr? (adseguy)

I had asked this in my other post, but never got an answer. Can I use the map signal, rpm, and afr while datalogging to tune? Because my datalogger doesn't capture in/Hg values. So at the moment I'm not sure when I'm at 2 psi or at 6 psi....would I just need to get a new map sensor that my zeitronix datalogger can read or is there another way to tune without it?
Old 03-02-2006, 09:53 AM
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Default Re: What's your target afr? (asianspeed)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by asianspeed &raquo;</TD></TR><TR><TD CLASS="quote">Hi,
I've started tuning my car and I just wanted to see what air/fuel ratios everyone is targeting. I'd like to take the discssion one step past getting a wideband and learning what to do next.

Please include whether your target afr are for street or track and conservative or agressive. Personally, I'm interested in a conservative daily driven tune.

This is what I'm targetting for:
13.5 AFR while NA.
12.5 AFR from 0psi to 3psi.
12.25 AFR from 3psi to 5psi.
12.0 AFR from 5psi to 7psi.
11.5 AFR from 7psi to 10psi.

So to all you tuners out there, please lend your knowledge and school me on the subject.

Thanks!</TD></TR></TABLE>

The mentioned vacuum levels above are around what I tune at.. but I tune 15.3ish:1 for the highway/interstate inHg levels (19-12) to get better gas mileage..

I woudl rather be a bit safer and go for this..

13.5 AFR while NA.
12.25 AFR from 0psi to 3psi.
11.7 AFR from 3psi to 5psi.
11.5 AFR from 5psi to 7psi.
11.5 AFR from 7psi to 10psi.
Old 03-02-2006, 09:55 AM
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