Necessary Or Not

wanna ask senior2 here,, ive newly change engine kelisa 1.0 to my kuncil.. is it necessary to use fuel regulator? some forment say yes,other say no.. ,emm =_=.. (heard that item can save fuel.. make me wanna install it,, but still in hesitating) any suggest n idea? tq

I quoted from other forummer explanation... if not mistaken i saw this thing in drex sifu fb. EA got sell, SARD or aerospeed brand if not mistaken. May be u can get opinion from him.

The explanation is correct. But if tuned to high pressure, more fuel goes in and therefore FC will be bad.
Anyway, as far as I know all fuel injected cars already have them but cannot adjust the return pressure only.....

Most newer Perodua/Toyota/Honda/Kia/Hyundai don't even use a return system. No regulator.
Fuel pressure is regulated by the fuel pump which has a PWM controller.

Just read again, no return system.....

indeed stock car already got regulator..but not adjustable...

it got the signal from vaccum point at intake manifold....u can create an adjustable regulator by installing T-vaccum controller (like the aquarium oxygen bypass ppl call "tulang ikan" to control boost) and put it on the regulator vaccum pipe....tadahhh....a rm2 fuel regulator is done....but tuning a bit hard la since u didn;t have fuel pressure meter...

So the newer car without return system cannot use this method......

Air leaking valve IS NOT a reliable mean to regulator regulate the fuel pressure.

No point in installing a fuel pressure regulator on standard cars. Even a slight increase in pressure will increase fuel supply as injector timing is not changed. This is only an upgrade for those which has modded their cars and the car is running lean and they need to get more fuel in. Using a FP regulator is just a easy and cheap means to go about increasing fuel which is not the correct way as it'll increase fuel everywhere, even in places of the fuel map where it is either correct or slightly rich.

Most and I mean 95-99% of the stock cars are running slightly rich from the factory (at full throttle or in O2 open loop) so a FP regulator will do nothing. At all other times the car is in O2 closed loop which is set at 14.7:1 which is the most efficient mix.

So only install a FP regualtor if you have modded your car and its running lean or when you have hit 80% injector duty and its not getting any richer, then you can cheat abit and put in a FP regulator. Then you have to remap the rest of the idle, cold start, hot start, and compensation maps and part throttle map again usually minus a few percent. proper way is to maintain the same pressure but up injectors and fuel pump to get the fuel delivery for your mods.

How about cars with performance cams and exhaust?

What's a slightly rich mixture when 14.7:1 is the most efficient ratio?

How about finer spray at the same duty cycle but higher pressure?