Target AFR tables

Fuel Supply & Ignition Systems
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panel
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Target AFR tables

Post by panel »

Anybody want to post/share up their target AFR tables they are tuning from?

Here's the one from the MS web site:

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MinamiKotaro
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Re: Target AFR tables

Post by MinamiKotaro »

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panel
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Re: Target AFR tables

Post by panel »

Are you not boosted anymore?
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miniman82
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Re: Target AFR tables

Post by miniman82 »

I suspect Minami has the same philosophy I do when it comes to target tables: pretty much cruise only is what I use it for. I don't personally trust any magic box, no matter how advanced or expensive it is, to make decisions about my fueling curve when under boost. Even if the computer itself is working perfectly 100% of the time, you are always vulnerable to issues with the wiring between the wideband and the ECU, and the wideband unit itself (failed sensors, fuses, software corruption, ect.). All it takes is a few seconds of bogus info to destroy the engine on boost, so I always tune the VE table in those areas by hand and set EGO off over 100 KPA. BTW, my table looks about the same as his does.
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Turbo_Manx_Maniac
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Re: Target AFR tables

Post by Turbo_Manx_Maniac »

AFR tables are very useful with Tuner Studio, if you use the "autotune" feature it will change VE's based upon what you want the AFR to be. Problem is most people don't really know what AFR to run under all the conditions, but with some trial and error you can get your car tuned very well. I would not use AFR tables in a closed loop mode, just for tuning.

Panel, I have a table worked out for my car, but it's mostly tuned for off roading. Although it does drive very well on the street it's not tuned for optimal gas mileage thus it could be made leaner in the cruise and decel areas. I'll post it up when I get home.
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MinamiKotaro
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Re: Target AFR tables

Post by MinamiKotaro »

panel wrote:Are you not boosted anymore?
I have a different table for boost.

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Turbo_Manx_Maniac wrote:AFR tables are very useful with Tuner Studio, if you use the "autotune" feature it will change VE's based upon what you want the AFR to be.
Whoa, there's an "autotune" in Tuner Studio? Where do I activate it? I can't seem to find it.
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panel
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Re: Target AFR tables

Post by panel »

MinamiKotaro ......how did you get those two tables? Does MS switch between the two automatically?
And in both your tables at 100KPA you have 2 different AFR's?
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Turbo_Manx_Maniac
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Re: Target AFR tables

Post by Turbo_Manx_Maniac »

MinamiKotaro wrote:
Turbo_Manx_Maniac wrote:AFR tables are very useful with Tuner Studio, if you use the "autotune" feature it will change VE's based upon what you want the AFR to be.
Whoa, there's an "autotune" in Tuner Studio? Where do I activate it? I can't seem to find it.
http://www.efianalytics.com/TunerStudio/

Look at the section called 'VE Analyze Live! '

Think you need to register to access or use it. Cheap enough though.
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Turbo_Manx_Maniac
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Re: Target AFR tables

Post by Turbo_Manx_Maniac »

MinamiKotaro wrote:
Turbo_Manx_Maniac wrote:AFR tables are very useful with Tuner Studio, if you use the "autotune" feature it will change VE's based upon what you want the AFR to be.
Whoa, there's an "autotune" in Tuner Studio? Where do I activate it? I can't seem to find it.
http://www.efianalytics.com/TunerStudio/

Look at the section called 'VE Analyze Live! '

Think you need to register to access or use it. Cheap enough though.
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MinamiKotaro
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Re: Target AFR tables

Post by MinamiKotaro »

panel wrote:MinamiKotaro ......how did you get those two tables? Does MS switch between the two automatically?
The one for VE Table 3 is always turned off. It's only used for tuning with MegaLog viewer. In the VE Analyzer it comes up as "AFR Bins 2".
And in both your tables at 100KPA you have 2 different AFR's?
Oops!

And I only have the free version of TS, so no autotune for me. :(
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Re: Target AFR tables

Post by klatin »

Minamikataro,

Any particular reason you are targeting 14.7 so much in your cruise maps?
The reason I am asking is that though 14.7 is considered best for minimum emissions, that is often not the case for older engine designs like the VW. Otherwise a very narrow window around 14.7 is only used in modern engines because of cat efficiency. Cats work ONLY in that window. But I'm assuming you don't use a cat.

However, stoichiometric (14.7) is the AFR where the most in-cylinder heat is released, resulting in highest EGT and CHT for a given load. But 14.7 does not produce the most power (needed at high loads only) and not the best fuel consumption (typically wanted at cruise or idle). Max heat is not good for an aircooled engine.
In cruise I think you would be better off running leaner (less heat and fuel), which requires more advance, unless your CHTs are too cold at cruise and you want to make up by producing more heat.

In my engine I'm running close to 14.7 only during the 2nd half of the warmup cycle to get the engine warm faster. Even at (warm) idle I am running ~16.5, albeit with large advance there (setting it such that I get the lowest MAP (most manifold vacuum) for a given idle speed, which results in best idle BSFC). However, that method requires careful tuning of tip-in fueling from idle and a fast reacting MAP sensor (directly at the manifold) to have a fast reacting ign. advance change during tip-in.
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Re: Target AFR tables

Post by panel »

klatin wrote: However, stoichiometric (14.7) is the AFR where the most in-cylinder heat is released, resulting in highest EGT and CHT for a given load. But 14.7 does not produce the most power (needed at high loads only) and not the best fuel consumption (typically wanted at cruise or idle). Max heat is not good for an aircooled engine.
In cruise I think you would be better off running leaner (less heat and fuel), which requires more advance, unless your CHTs are too cold at cruise and you want to make up by producing more heat.

.
What we should do is post up the Advance tables to match ?
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Blobber
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Re: Target AFR tables

Post by Blobber »

klatin wrote:Minamikataro,

Any particular reason you are targeting 14.7 so much in your cruise maps?
The reason I am asking is that though 14.7 is considered best for minimum emissions, that is often not the case for older engine designs like the VW. Otherwise a very narrow window around 14.7 is only used in modern engines because of cat efficiency. Cats work ONLY in that window. But I'm assuming you don't use a cat.

However, stoichiometric (14.7) is the AFR where the most in-cylinder heat is released, resulting in highest EGT and CHT for a given load. But 14.7 does not produce the most power (needed at high loads only) and not the best fuel consumption (typically wanted at cruise or idle). Max heat is not good for an aircooled engine.
In cruise I think you would be better off running leaner (less heat and fuel), which requires more advance, unless your CHTs are too cold at cruise and you want to make up by producing more heat.

In my engine I'm running close to 14.7 only during the 2nd half of the warmup cycle to get the engine warm faster. Even at (warm) idle I am running ~16.5, albeit with large advance there (setting it such that I get the lowest MAP (most manifold vacuum) for a given idle speed, which results in best idle BSFC). However, that method requires careful tuning of tip-in fueling from idle and a fast reacting MAP sensor (directly at the manifold) to have a fast reacting ign. advance change during tip-in.
May we not see your afr-table?
Then it is easier to compare with the other tables.
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panel
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Re: Target AFR tables

Post by panel »

Here's mine. In the 'advance table' I was trying to get the car to idle faster without using the idle valve and didn't succeed. I had higher timing in the high map low RPM and added cold advance but like I said above......it didn't make the motor run any faster. Maybe I'm doing something wrong?

Anyhow.........I'd also like some feedback if you want to throw it my way. Always looking,listening and learning :!:

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1955cc66bug
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Re: Target AFR tables

Post by 1955cc66bug »

Is there no way to get your idle valve to work the way you want it to....even if it came down to throwing a toggle in there somewhere to cut the power to it after your engine is warm. I just think theres no way to get a cold engine idle very well any way you slice it. I have been trying to do the same without a valve with no luck. I added cold advance just to see if the car would drive better cold....seems to help somewhat but still stumbles a bit for a few blocks. But there's no way in hell it will idle not matter how much fuel or timing I throw at it. I think thats where my dual 44's has my EFI beat LOL
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