trinituner.com

OK So I have a bone stock RB25DET, A Walbro 255 external and I am now ready to replace the stock fuel regulator with an aftermarket unit because the engine was "breaking up" when I tried to floor it at 10Lb of boost

1: What is the RB25 Stock fuel pressure?
2: What is the maximum safe level I can carry it to for a stock engine
3: At 10Lb Boost What pressure should I carry it up to?

Another thing is I see the regulator has three liines

Feed from pump
Out to fuel rail
and line that seems to be for a vacume hose?

Stock fuel pressure is around 35-38psi you can run up to 40psi base pressure.

Thanks man....I though I signed off o this thread...anyway, yeah yu're right, the stock pressure was 35Psi.

What's the advantage of running at 40 base pressure on a stock motor?

If the car breaking up on WOT when on boost, check your plugs and the gapping.

i run 40psi base pressure and there is small increase in power, around 3-4000rpm,

ill try it at 40psi, hope fuel consumption doest go up too much.

I have same set up on my RB / walbro with 10psi and stock everything else and got same problem when boost was raised. Problem went away when i gapped plugs to .8mm

im running it at 43psi / 3 bar, revs smoother and a bit faster.