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Tuner
FPR/Injector data question
, if there is an aftermarket FPR with no vacuum line plugged into the nipple plugged in?. The fpr should be set at 58 psi,right?
So if the little nipple doesn?t have a vacuum on it, would it be non referenced & I?d have to make the adjustments on fuel injector data ?
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You can run lower pressure. Fuel pumps flow more fuel at lower pressure. It will reduce electrical strain. It will reduce fuel heating. Fuel system components will last longer.
If you are tuning the engine anyways and have plenty of injector size to fuel the engine you can run a lower pressure, say 35 to 40psi. You would need to calculate the new injector flow rate for the Injector size table to do this and there would probably be a little tuning involved elsewhere. I always run a base pressure of 38psi and then the vacuum reference on a vehicle with 15 to 18" Hg of vacuum will pull that down to around 30psi during idle. This is a factory methodology for many cars. For example 1995-2002 Nissan skyline and Toyota Supra run 44psi baseline fuel pressure and the vacuum reference pulls that down around 36psi during idle. They do this for the reasons I mentioned and also because of the turbochargers which rise the fuel pressure high during boost 1:1. For 20psi of boost for example it will add 20psi of fuel pressure. So if they start off like 60psi imagine 80psi on a factory engine what kind of fuel pump and voltage drop and fuel heating and so forth that would cause.
If you do not intent to tune the engine and just trying to setup a stock fuel system for a stock tune on stock injectors then its probably a good idea to just go with the 60psi default. But keep in mind in the future if you start tuning something there is your chance to reduce the fuel pressure provided the injectors can supply enough fuel. I recommend a referenced regulator if you can manage because the reference drops the pressure for idle/cruise to take strain/load away from the fuel pump and fuel components.
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Tuner
If the vehicle injector data is referenced how would I update?
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A tune file contains many injector adjustments. You would need to know what you are doing to make a change and be able to re-tune as needed for that change.
As usual I am not telling people what to do. I am only sharing what is possible so you can attain those benefits if you so choose to pursue them.
It may be a day , month , year , decade from now you are able to do these things. But if you didn't know they are even possible you might never do it or aware it exists.
Education
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Use the 0kPa column values for flow and offset for all columns to the right.
For details see post #16 and on here:
https://forum.hptuners.com/showthrea...-injector-data
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