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Fuel Reg base pressure

Mase

By Mase,
in Engines & Forced Induction

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Mase Mentor

Mase

Posted
Posted

I've got a malpassi rising rate fuel reg in my rb20det powered s13. I had it set at about 40psi and i removed the vacuum line on my stock fuel regulator. I went from getting 350klms out of a tank to about 500klms. Off boost was more responsive and i was pretty happy with it. However i kinda think it's too good to be true so im a little worried i may be running too lean. I only have minor mods: rb25 turbo, stock boost (8psi), pod and the fuel reg. Im getting an exhaust tomorrow finally!

the injectors were recently flow tested and cleaned and are spot on. Do you think i should drop the pressure back down to 40psi, or what would be your opinion?

thanks

Jayson

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muffas 180 Enthusiast

muffas 180

Posted
Posted

Did you set the reg at idle with the vacuum line disconnected to 40 psi? If you set it to 40 with the vac line connected you dont need that much pressure. My reg was set on the dyno at full throttle and load to 90psi to squeeze 229.2 kws at wheels with standard injectors. The pressure at idle it 40psi with the hose connected. For standard boost 65 psi at 10psi boost will be heaps.

Michael...

Sydneykid Grand Master

Sydneykid

Posted
Posted

Hi mase. standard RB20DET fuel pressure is 36 to 38 psi at idle with the vacuum hose disconnected. So 40 psi is a little above standard, car should be running slightly richer and using more fuel. I smell a rat, I would do a power run on the dyno, watch the boost pressure and in particular the A/F ratios. One power run up through the rev range, take about 20 minutes including on and off the roller time.

Hope that helps

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