INJEN and AEM Shootout Complete!!!!!
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Joined: Oct 2001
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From: San Diego
Phantom, nice idea. Sounds like it might work pretty well.
Had a question still about cutting the plastic that leads into the MAIN grill area. Does that need to be cuz as well or maybe recommened to allow a little more air flow into where the filer is. Or maybe just cutting some 'breather holes there?
Looking forward to your pics.
Had a question still about cutting the plastic that leads into the MAIN grill area. Does that need to be cuz as well or maybe recommened to allow a little more air flow into where the filer is. Or maybe just cutting some 'breather holes there?
Looking forward to your pics.
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From: Houston
Zot,
You really don't need to cut out the front grill if you are going to cut the plastic wall next to the radiator. But, with that wall gone...the air filter is too exposed in my opinion...I rather cut the front air duct and use some plastic and epoxy to channel air from directly hitting the air filter.
My friend has the pics...I will post them as soon as he e-mails them to me!
You really don't need to cut out the front grill if you are going to cut the plastic wall next to the radiator. But, with that wall gone...the air filter is too exposed in my opinion...I rather cut the front air duct and use some plastic and epoxy to channel air from directly hitting the air filter.
My friend has the pics...I will post them as soon as he e-mails them to me!
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From: Laurel
[QUOTE]Originally posted by ultimate lurker
[B]O.k. folks, here is the deal:...
...However, it does still apply the long term trim numbers to the WOT map...If you would like more info, I suggest contacting the fellows at Hondata or Zdyne.
[B]O.k. folks, here is the deal:...
...However, it does still apply the long term trim numbers to the WOT map...If you would like more info, I suggest contacting the fellows at Hondata or Zdyne.
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From: Houston
I have pictures of how I made the splash guard for the AEM air filter if you have the front fake brake duct cut open...
http://www.s2000online.com/forums/showthre...4310#post344310
Here is a shot of splash guard (used epoxy to fix it to the inside of the duct). The AEM filter sits right behind it (out of sight).
http://www.s2000online.com/forums/showthre...4310#post344310
Here is a shot of splash guard (used epoxy to fix it to the inside of the duct). The AEM filter sits right behind it (out of sight).
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Joined: Oct 2000
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From: Davie, FL
Since this hasn't been asked yet - how difficult is it to replace/service the air filter with this mod. Do you have to remove the front bumper to do so?
The debate about ECU behavior is interesting - please keep it alive!
The debate about ECU behavior is interesting - please keep it alive!
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From: Charleston
Originally posted by CoralDoc
Since this hasn't been asked yet - how difficult is it to replace/service the air filter with this mod. Do you have to remove the front bumper to do so?
Since this hasn't been asked yet - how difficult is it to replace/service the air filter with this mod. Do you have to remove the front bumper to do so?
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From: Phoenix
Could you give some details on how to remove the front bumper? You mentioned that it was just 4 bolts, but the Helm manual shows over a dozen...I am guessing that this means that some are optional.
Thanks,
Tanq
Thanks,
Tanq
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From: You wish
Jim,
MY sources are myriad. MY sources include information straight from Honda. Allow me to provide you with just one more besides what I have already listed:
Fuel and Emissions Systems - Pg 11-12 FSM
Short Term Fuel Trim:
The air/fuel ratio correction coefficient for correcting the amount of injected fuel when HO2S feedback is in the closed loop status. (there is a whole paragraph essentially detailing how when the reading is weak, Short Term trim goes up and vice-versa).
Long Term Fuel Trim:
Long term fuel trim is computed from short term fuel trim and indicates changes occuring in the fuel supply system over a long period of time.
This is not to say that the ECU does not take IAT, ECT, Barometric pressure, etc. into account, but when it comes to fuel trim information, it is solely derived from the HO2S sensor data - according to Honda.
Common sense dictates that any long term changes in fuel trim (i.e. Long Term Fuel Trim numbers) must be applied both in open and closed loop modes. If they are not, you risk running dangerously lean or excessively rich in open loop (excessively rich being a relative term with this engine). It is not enough to know MAP, temp and throttle position data. If you alter the flow characteristics of the engine, it may flow more air for the same MAP, temp and TP inputs than it did before the modification. This must be accounted for by tweaking the fuel map. Honda ECU's are notoriously good for compensating for modifications (sometimes not the way we want) in my past experience.
Furthermore, anecdotal evidence gained from making modifications on both the F20C and other OBDII+ equipped Hondas shows that the ECU does apply corrections, or learns to adjust, mixture for open loop operation (not saying it learns in open loop, but it does learn to adjust there). One might argue that this would only relate to fuel system issues, but in reality, the only way the ECU has to monitor fuel system performance is O2 sensor data. There are no inputs for fuel pressure, injector efficiency, etc. Thus, any change which creates a long term trim alteration, be it fuel or air related, can have an effect on open loop fuel map corrections.
Finally, as I have mentioned, the folks at Hondata and Zdyne have done extensive reverse engineering on the Honda ECUs. They have totally disassembled them and mapped their actual output responses across a huge array of conditions and variable combinations. And lets face it, we're not talking about hugely complex processing systems either in the grand scheme of things. Considering the results they have achieved with their systems, I have absolute faith in their information. I have also spent considerable time chatting with the principals of both companies (long before Hondata even came to the U.S. in fact) and trust their results. Straight from the horse's mouth then, the ECU disregards short term trim in open loop, but does not disregard long term.
I hope that sheds some light on the issue for you. I suppose I could have misconstrued something in my information - and I'll be the first to bow to the truth if that's the case - but nothing I've seen to date says otherwise.
UL
MY sources are myriad. MY sources include information straight from Honda. Allow me to provide you with just one more besides what I have already listed:
Fuel and Emissions Systems - Pg 11-12 FSM
Short Term Fuel Trim:
The air/fuel ratio correction coefficient for correcting the amount of injected fuel when HO2S feedback is in the closed loop status. (there is a whole paragraph essentially detailing how when the reading is weak, Short Term trim goes up and vice-versa).
Long Term Fuel Trim:
Long term fuel trim is computed from short term fuel trim and indicates changes occuring in the fuel supply system over a long period of time.
This is not to say that the ECU does not take IAT, ECT, Barometric pressure, etc. into account, but when it comes to fuel trim information, it is solely derived from the HO2S sensor data - according to Honda.
Common sense dictates that any long term changes in fuel trim (i.e. Long Term Fuel Trim numbers) must be applied both in open and closed loop modes. If they are not, you risk running dangerously lean or excessively rich in open loop (excessively rich being a relative term with this engine). It is not enough to know MAP, temp and throttle position data. If you alter the flow characteristics of the engine, it may flow more air for the same MAP, temp and TP inputs than it did before the modification. This must be accounted for by tweaking the fuel map. Honda ECU's are notoriously good for compensating for modifications (sometimes not the way we want) in my past experience.
Furthermore, anecdotal evidence gained from making modifications on both the F20C and other OBDII+ equipped Hondas shows that the ECU does apply corrections, or learns to adjust, mixture for open loop operation (not saying it learns in open loop, but it does learn to adjust there). One might argue that this would only relate to fuel system issues, but in reality, the only way the ECU has to monitor fuel system performance is O2 sensor data. There are no inputs for fuel pressure, injector efficiency, etc. Thus, any change which creates a long term trim alteration, be it fuel or air related, can have an effect on open loop fuel map corrections.
Finally, as I have mentioned, the folks at Hondata and Zdyne have done extensive reverse engineering on the Honda ECUs. They have totally disassembled them and mapped their actual output responses across a huge array of conditions and variable combinations. And lets face it, we're not talking about hugely complex processing systems either in the grand scheme of things. Considering the results they have achieved with their systems, I have absolute faith in their information. I have also spent considerable time chatting with the principals of both companies (long before Hondata even came to the U.S. in fact) and trust their results. Straight from the horse's mouth then, the ECU disregards short term trim in open loop, but does not disregard long term.
I hope that sheds some light on the issue for you. I suppose I could have misconstrued something in my information - and I'll be the first to bow to the truth if that's the case - but nothing I've seen to date says otherwise.
UL
Originally posted by jschmidt
I'm looking for your source of the information. So are you saying that YOUR source of information is reverse engineering? That doesn't really sound reliable enough to be "here's the deal" especially as it concerns an ODBII system and an ECU that no one (to my knowledge) has been able to crack. How do you know what factors and variables contribute to long-term trim settings. How do YOU know that long-term trim is derived from short-term trim? Can you say, for example, that these two trims are even controlled by the same data/sensors? Can you say that they are active variables rather than map selections within your suggested range? These are, of course, reasonable assumptions/possiblities but before I accept them as facts, I'd like to know the source. You seem to imply that trim is variable and eminates from the O2 sensor data. Perhaps your explanation was simplified; otherwise, I don't think any car with active trim uses O2 sensor data alone.
I'm looking for your source of the information. So are you saying that YOUR source of information is reverse engineering? That doesn't really sound reliable enough to be "here's the deal" especially as it concerns an ODBII system and an ECU that no one (to my knowledge) has been able to crack. How do you know what factors and variables contribute to long-term trim settings. How do YOU know that long-term trim is derived from short-term trim? Can you say, for example, that these two trims are even controlled by the same data/sensors? Can you say that they are active variables rather than map selections within your suggested range? These are, of course, reasonable assumptions/possiblities but before I accept them as facts, I'd like to know the source. You seem to imply that trim is variable and eminates from the O2 sensor data. Perhaps your explanation was simplified; otherwise, I don't think any car with active trim uses O2 sensor data alone.