if i put a turbo on my ka i have the turbo and the larger injector so i tune my fuel in to the engine via safc … but do i need a fuel pressure regulator so i can increase the persure of the fuel system??? cuz i am confused on these 2 things plz explained cuz if the safc can give more fuel why do i still need the regulator ? thx
… S-acf does not ‘tune’ the fuel… if you think like tha thenall you’ll have is a blown engine… Your best option is to a) do allot of learning about the basics of FI and what to use to affect what subsystem. b) take it to a tuner to do it right.
an A-afc ‘can’ be used as part of a much larger equation… but as the sole tuning device, even with a AFPR it’s doing nothing. if someone tries to tell you otherwise ask them how a linear tuning device can effect a 3D FI lookup table…
safc will alow you to fool the ecu to make it inject more fuel or remove fuel.
a fuel pressure regulator will increase fuel pressure to add more fuel under boost…
usually you want 1:1 fuel pressure under boost, so the injector tip doesn’t see a pressure differnetial because of boost, and allow it to operate at a rating of 43.5 psi.
:bigok:
As I said an S-afc is hooked into the MAF, it intercepts and changes the air sensor signal to fool the ECU… it does not chage the fuel… this is really simple kids. all you’ve done is change the base gain on the air sample side… this does not effect anything to do with load variations.
An ajustable fuel pressure regulator is 1:1 or sometimes 2:1 however that is not enought for a static fuel pressure/fixed table ECU. Std. fuel to air ratio is ~ 10-14:1 hence the reason they make rising rate fuel pressure regulators, example: a static fixed Vortech RRFPR or a Vortec Super where both base line rqte and ratio to boost reference is adjustable.
This of course does not even include the nessicity for some form of ignition/ timing boost reference retard system…
not all companies use 43psi either Ford uses 38.7 and some others use 40 or 41 psi. You’d best make sure what your specs. are based on factory specs if you plan to use the OEM ECU as the base line.
1.)let say i have a stock 240sx and i got and change it to a walbro fuel pump is there any thing bad going to happen to my engine
2.) i have a stock 240sx i go and change out the fuel injectoer to a 450 ones what happen to the extra fuel going in to the combustion chamber? Is it when the S-afce comes in the adjust the fuel so after i change out the injector the engine will not run rich.
3.) why do i need something like SAFC when i install a turbo?
thanks
4.) what happen if the pressure in the fuel system is too high or too low? what is the right pressure in a car and how to determine it…
5.) cand I just change out the fuel injector if i want to turbo my car?
6.) okay i turn up my boost in a sr20 will the ecu know to add more fuel to the added air going in???
Is it when the S-afce comes in the adjust the fuel so after i change out the injector the engine will not run rich.
As I said an S-afc is hooked into the MAF, it intercepts and changes the air sensor signal to fool the ECU… it does not chage the fuel… this is really simple kids.
apparently i didn’t make it simple enough for you… ](*,)
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the fuel pump will only pump as much fuel as your FPR ( oem or aftermarket) will allow, that’s it. * the exception being that the FP does not over power the bypass ability of the fuel system
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you REALLY need to do some reading before you go messing with your cars major subsystems. toomuch fuel into the chamber means the mix is off, mix is off. you get any numbers of things, from simple low power and poor gas milage to not starting becuse the chamber is flooded
3 YOU DO NOT NEED ONE there are any number of options from simple SMT-6 piggybacks to full stand alone ECU’s… but you DO require something to manage the fuel and spark! again this is really best left TO someone who has a clue what they are doing… ISBN 0-8376-0300-5 read this book.
4 read the above book…
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read the book…
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the OEM ECU on an SR20 will, to a point function with the boost turned up. the failure comes in both fuel supply and air flow supply and the limits of the boost table map.
unless you like blown engines in your car I seriously suggest you don’t touch it… you don’t know enough to do the right thing.
uh last time i checked this was a 240sx forum, not ford. you wanna fight?
god ive never seen someone make such a simple subject so complicated
its disgusting
thank you all… i am sorry but i am the kind of person want to know everything to the bottom line … i will for sure go and check out the book…