Evilempire1.3JZ-GTE;1509953 said:
Fuel cut is not a real issue get a higher PSI Map then re-map it down with a AFC or fuel managment systemn like piggyback. the fuel cut limit is the sensor itself.
But boosting more then fuel cut on oem fuel system or turbo is a waste anyway.
AS far as Standalone Vs piggy back the stand alone is way better!
Allows for sequential injection & firing, timming control, multi maps, built in 30psi map, boost control RPM redline vvti adjust all of that valet mode can handle any drastic mods thrown at it like if you change turbo because the old ones blow just slap a bigger turbo on larger fuel injectors then trim & fine tune the base map
boost control can be tuned while driving the car with a carputer. there is tons of things you can do like turn on electric fans some standalones have turbo timers built in etc.. I could go on forever on why a stand alone is better.
like if you blow the motor up just throw a cheap aristo 2JZ in your car trim the map and drive.
Evil,
I understand that tuning more than fuel cut with oem and turbo is a waste, but I fail to understand how reloading a larger PSI map will change fuel cut on a piggyback.
My understanding is that at 4.4V from your map sensor (right at fuel cut), your ecu will calculate how much fuel to put in based on RPM. So by just loading a higher PSI map into the system and keeping the injectors the same then you will run lean becuase whether you have a higher psi map or lower psi map 4.3v is 4.3v as far as injection duty the ecu outputs. So anything above this threshold is just clamped and injector duty is not raised. Piggybacks do not control injectors as they let the ecu control that. ECU does not know what map you loaded only voltage from the stock map which the piggyback is modifying and stock fuel map.
And I agree that a standalone is definitly the way to go as I am running a PowerFC in my supra.
I am still learning so please dont mind my questions.
BTW the piggyback i am tuning is running walbro fuelpump, aftermarket fuel reg, 440's and holset turbo.