S2000 Under The Hood S2000 Technical and Mechanical discussions.

N/A car with AEM/VAFC

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Old 06-18-2003, 09:55 AM
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Default N/A car with AEM/VAFC

OK,
Here is a question...
Assuming I had a stock S2k.Do you think there would be a difference in HP if I were to run a properly tuned VAFC compared to a properly tuned AEM EMS .....I personally do not see any possible advantage in this. If I am incorrect, I would like to know why?????

Thanks
Beroz
Old 06-18-2003, 10:20 AM
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There is definitely more power to be made from an AEM than a V-AFC, since you can adjust fuel curves more precisely and adjust timing. However, the added cost and tuning effort is hard to justify for a few extra ponies.
Old 06-18-2003, 10:45 AM
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hummm...... I am not an expert and this is why i'm asking the questions.

How much more fuel fine tuning do you need ? and would fine tuning the fuel curve even give 5 HP through out the band ?

Timing tuning is a very interesting topic, I do not recall anyone writhing about this, All I have been reading is that FI guys always retard their timing to be safe. Has anyone advanced their timing to obtain HP. What HP through out the power band is expected from this?

gernby, I had a feeling you would be the first people to answer....Thanks

Thanks
Beroz
Old 06-18-2003, 12:56 PM
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[QUOTE]Originally posted by beroznikmal
[B]hummm...... I am not an expert and this is why i'm asking the questions.

How much more fuel fine tuning do you need ? and would fine tuning the fuel curve even give 5 HP through out the band ?
Old 06-18-2003, 06:12 PM
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UL or anyone else please chime in.......................
Old 06-18-2003, 06:59 PM
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something else I found myself wondering as I get closer and closer to buying a computer, is how much will the honda ECU un-tune the piggy-back computers as it "learns". There has been some speculation as to the ECU re-learning after VAFC's have been installed and undoing some of the tuning...... This superstition is pushing me more towards the AEM...... again UL, and anyone else, some insight is very welcome.
Old 06-18-2003, 07:14 PM
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I followed Gernby's advice and set my throttle settings so that the vafc only kicks in at higher throttle. I think he said something about the ecu not compensating because the vafc doesnt start affecting air fuel ratios until you are almost wot which is fine with me. My car runs real good with aem cai and vtec controller and even 3 months after it still pulled on my brothers stock s2k noticeably.
Old 06-18-2003, 07:31 PM
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Does this have to do with when the car is not WOT the ecu receives a feedback loop and there for corrects as it goes along.... if the throttle settings are set high enough such that it only kicks in when the feedback loop is no longer used, the stock ECU will not learn and try to correct thus not untuning what was once tuned...????
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Old 06-18-2003, 07:37 PM
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I'm not sure I follow you loop theory but either way it just doesn't sit well with me personally..... it feels like I'd have 80% control with a piggy back and 100% control with a stand alone..... just my opinion....
Old 06-19-2003, 07:25 AM
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This is what I think I understand about the ECU under non WOT.

The map pretty much tells the ecu information about RPM under a certain load. Well based on the map and the 02 sensor, the ecu will try and hold a certain A/F ratio value....

when the air fuel ratio is not at what is desired (because of the vafc interference) the ECU will under or over compensate the original map value to reach the set desired a/f ratio value set by the stock ecu.

To eliminate this " learning" one may set when the vafc kicks in, to a higher value or, often reset the ecu.

Ok, back to the topic of discussion. Can anyone tell me the answer to my initial question......

Beroz


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