FPR Gain or not again?
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????won't the afc fail eventually because of this problem as well?
The mugen ecu I have works wonders. But I do notice changes in the way my car runs and I'm sure Fuel Pressure(physical)
has something to do with it. Like I said, when my tank is almost empty my car runs very well. Am not sure what that means as far as physical fuel pressure. Ideas? I will set my fpr in that direction and see. the mugen ecu is pre mapped and loses sensor disables, If my suspicions are true buiding more pressure in the line via regulator or pump is going to help.
As far as I see this has nothing to do with A/F mixture in a computer controlled Fuel Injected enviroment Because adding fuel pressure before the injectors won't change the air/fuel ratio after the computer compensates. But, if computer calls for more fuel in mix at WOT or whenever and pressure in line is not there then performance is lost?
Anyone with data?
????won't the afc fail eventually because of this problem as well?
The mugen ecu I have works wonders. But I do notice changes in the way my car runs and I'm sure Fuel Pressure(physical)
has something to do with it. Like I said, when my tank is almost empty my car runs very well. Am not sure what that means as far as physical fuel pressure. Ideas? I will set my fpr in that direction and see. the mugen ecu is pre mapped and loses sensor disables, If my suspicions are true buiding more pressure in the line via regulator or pump is going to help.
As far as I see this has nothing to do with A/F mixture in a computer controlled Fuel Injected enviroment Because adding fuel pressure before the injectors won't change the air/fuel ratio after the computer compensates. But, if computer calls for more fuel in mix at WOT or whenever and pressure in line is not there then performance is lost?
Anyone with data?
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Viscreal,
As long as the pump pickup is uncovered, fuel pressure should be fine. So your feeling of better performance on low gas is probably weight related. I'm kind of concerned that our fuel filter is in the fuel tank though. I like to change mine every 15k-20k given the quality of gas we get, but that's just not an option now.
I don't think that more fuel pressure will necessarily give us more power. I just think that the ECU goes into a "safe" mode when thigns start getting lean (i.e. with mods) and that means excessive pulsewidths on the injectors. Older Honda ECU's would just start to adjust using fuel trim, but the S2000 ECU appears to be a little overzealous, probably in the interest of protecting the engine. With more pressure, we may not get that lean condition and avoid the "safe" mode. An ECU reset is probably useful in this situation.
On the V-AFC, the reason it shoudl work is that it has a WOT mode. The ECU only looks at the O2 sensor for rich/lean conditions under part throttle. This is determined by the throttle position sensor (TPS). The pecentage of throttle where the ECU switches to WOT is preset. At what for the F20C I don't know, but my CRX was 90% (I've now got it at 70%). When the ECU changes to WOT or open loop mode, it is only concerned with a few variables: engine speed(RPM), manifold pressure(MAP), air temp(IAT), knock sensor(KS) and fuel trim (both long term and short term). Coolant temp may play a role, but I don't know. So, what the V-AFC does, as I understand it, is only alter the MAP reading to the ECU when the TPS voltage indicates WOT. Thus, the ECU doesn't know that the mixture may have gone out of bounds (probably leaner for power). And when you retrun to part throttle, closed loop operation, everything is back to the way the ECU expects it to be, so your fuel trim corrections don't get screwed up and remove your power gains.
Older tools like the Field SFC-VTEC (which I've used on other cars) altered mixture all the time (part and WOT) so that the ECU could dial out the gains.
I can't wait till I get a chance to tune an S2k with the V-AFC (hint, Mingster!) :-).
UL
As long as the pump pickup is uncovered, fuel pressure should be fine. So your feeling of better performance on low gas is probably weight related. I'm kind of concerned that our fuel filter is in the fuel tank though. I like to change mine every 15k-20k given the quality of gas we get, but that's just not an option now.
I don't think that more fuel pressure will necessarily give us more power. I just think that the ECU goes into a "safe" mode when thigns start getting lean (i.e. with mods) and that means excessive pulsewidths on the injectors. Older Honda ECU's would just start to adjust using fuel trim, but the S2000 ECU appears to be a little overzealous, probably in the interest of protecting the engine. With more pressure, we may not get that lean condition and avoid the "safe" mode. An ECU reset is probably useful in this situation.
On the V-AFC, the reason it shoudl work is that it has a WOT mode. The ECU only looks at the O2 sensor for rich/lean conditions under part throttle. This is determined by the throttle position sensor (TPS). The pecentage of throttle where the ECU switches to WOT is preset. At what for the F20C I don't know, but my CRX was 90% (I've now got it at 70%). When the ECU changes to WOT or open loop mode, it is only concerned with a few variables: engine speed(RPM), manifold pressure(MAP), air temp(IAT), knock sensor(KS) and fuel trim (both long term and short term). Coolant temp may play a role, but I don't know. So, what the V-AFC does, as I understand it, is only alter the MAP reading to the ECU when the TPS voltage indicates WOT. Thus, the ECU doesn't know that the mixture may have gone out of bounds (probably leaner for power). And when you retrun to part throttle, closed loop operation, everything is back to the way the ECU expects it to be, so your fuel trim corrections don't get screwed up and remove your power gains.
Older tools like the Field SFC-VTEC (which I've used on other cars) altered mixture all the time (part and WOT) so that the ECU could dial out the gains.
I can't wait till I get a chance to tune an S2k with the V-AFC (hint, Mingster!) :-).
UL
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