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Discussion Starter #1 (Edited)
1994 Supra 6speed
220k miles on original motor
SP Torque monster turbo kit. 6262
ID725's, aeromotive 340
Stock exhaust
AEM Infinity6

Video illustrates some of the features of the Infinity and how well it can handle some bad situations...

https://www.youtube.com/watch?v=vMHkJFqaQPs
 

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A lambda of .84 (afr of 12.3) at 204kpa (15psi) at 6000rpm is considered a bit lean to most. But more to the point of your demo it is a bit off the target of .77 (afr 11.27) if you go back and review the log as soon as you remove the pressure source line the car goes steady lean. The map does a better job maintaining target once you unplug the map and the pressure source but still is a bit off and last KPA value seen is 249 (22psi) and the car dips in the a lambda of .83 (afr 12.15) again.
 

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Discussion Starter #3
A lambda of .84 (afr of 12.3) at 204kpa (15psi) at 6000rpm is considered a bit lean to most. But more to the point of your demo it is a bit off the target of .77 (afr 11.27) if you go back and review the log as soon as you remove the pressure source line the car goes steady lean. The map does a better job maintaining target once you unplug the map and the pressure source but still is a bit off and last KPA value seen is 249 (22psi) and the car dips in the a lambda of .83 (afr 12.15) again.
You cannot determine the target AFR without knowing what the stoich AFR is of the fuel I am using, in other words its not 12.3 and its plenty safe, no worries. Also the log you are referring to does not have O2 feedback enabled. But you are correct its not perfect, with O2FB it will be damn near perfect.
 

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That is true about the fuel when converting to and AFR number so what fuel are you running? But no matter the fuel you are using Lambda values hold true and it is a fair amount off target.
 

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Discussion Starter #5
That is true about the fuel when converting to and AFR number so what fuel are you running? But no matter the fuel you are using Lambda values hold true and it is a fair amount off target.
The Lambda being off target is most likely due to the injectors running near their max duty cycle. A larger injector to demonstrate this feature would have been better, as well as having the lambda feedback working.
 

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If the injectors are near the max duty cycle at 204 kpa why then in the next pull is the car running 240 kpa? nearly 7 more psi of boost? Also why do you have lambda feed off in an ecu that was specifically designed to use it. Also the AEM will relay on that o2 feedback to adjust the injector duty when you have a fuel pressure issue.

I do ask again what FUEL you are using as you alluded to that you may not be using pump gas?
 

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Discussion Starter #7
If the injectors are near the max duty cycle at 204 kpa why then in the next pull is the car running 240 kpa? nearly 7 more psi of boost? Also why do you have lambda feed off in an ecu that was specifically designed to use it. Also the AEM will relay on that o2 feedback to adjust the injector duty when you have a fuel pressure issue.

I do ask again what FUEL you are using as you alluded to that you may not be using pump gas?

That car was never running 240kpa in any of the pulls, I dont know what you are talking about. It was off to illustrate that Infinity will compensate for fuel pressure loss without o2fb. It does not rely on the wideband to compensate for fuel pressure loss. It helps yes. It was turned back on dont worry. E10 pump
 

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At 1.53 in the video you can clearly see KPA IS 249



Is this due to the unplugging of it? The AEM jumps up on the VE map to the 250kpa cell at that moment even with your raw reading 344kpa. It just appears that car is seeing the 249kpa OR at least the AEM is seeing that it does. It may just be the sensor being unplugged at the AEM is taking a second to jump to the default setting for the map sensor value.

E10 is considered pump gas as most gas at the gas station has a disclaimer for 10% ethanol content. So my AFR values posted in my original post in regards to those lambda values are in most cases considered accurate in this situation. Therefor the car was at 12.3 afr on 15psi with the boost feed line removed from the FPR.

But the AEM does have a blend table for Ethanol content assuming that the car has a sensor installed on it. SO if the car does then the AEM depending on the blend table setup default is linear in the Infinity so the AFR would be

Stoich of 10% ethanol is 14.13. Meaning a lambda target of .77 would be (afr 10.88) and .84 (afr of 11.86) Taking that into consideration it does seem a bit safer but still the AEM is almost a whole AFR point off of target.
 

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Discussion Starter #9
At 1.53 in the video you can clearly see KPA IS 249

That is for a split milisecond right when the MAP sensor is being pulled out. The car doesnt actually see that boost which can be clearly seen in the dyno graphs.
 

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Is the analog 1 signal on your a dyno an independent sensor for map pressure? If so then I would feel more confident in saying the KPA value of 249 is caused by the sensor being unplugged as your analog 1 line stays steady in the video.
 

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Discussion Starter #11
Is the analog 1 signal on your a dyno an independent sensor for map pressure? If so then I would feel more confident in saying the KPA value of 249 is caused by the sensor being unplugged as your analog 1 line stays steady in the video.
Yes Analog1 is my dynojet map sensor its a separate sensor that I hooked up to a boost reference on the car. I wouldnt go through all that trouble to fake some results, AEM is not paying me.
 

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I'm kind of confused....is this a fail safe setup, or something that will just try and make sure the car stays running if something goes wrong? I'm just curious because If I start losing fuel pressure, I want the ECU to alert me and shut everything down so nothing gets hurt. Can you clarify for those of us that are wondering how your "fail safes" work.
 

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Discussion Starter #13
I'm kind of confused....is this a fail safe setup, or something that will just try and make sure the car stays running if something goes wrong? I'm just curious because If I start losing fuel pressure, I want the ECU to alert me and shut everything down so nothing gets hurt. Can you clarify for those of us that are wondering how your "fail safes" work.
It can be set up to trigger a check engine light. If the fuel pressure loss cannot be compensated for there is a lean cut that will cut the engine.
 

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A "new generation" standalone ECU can compensate for some loss of fuel pressure by "running the injectors harder" IE increase your duty cycle once it sees an issue or apply other measures to slow the fuel requirements needed. Reduce the engines power by reducing timing or reducing boost.

If the issue is so great that the computer can not compensate for it in other ways then the lean protection will come into factor and the ecu may then apply a full ignition cut similar to a boost cut on older/stock ECUs.

If the car can still be ran within a safe AFR with a small issue a customer may still want this to happen IE in a road race or a drag race in the finals of an event. You may not want to cut the car off completely if are able to maintain operation with the engines parameters for safety.

How the ECU reacts to an issue is decided by the tuner and the customer. The ABILITY to react to the issue is decided by the ECU's hardware and software.

The point of this video was a to show the ECU's ABILITY to achieve this protection.
 
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