Nissan VQ35DE Base Fuel Pressure

Good Morning,

I am curious if anyone can tell me what they use as the base fuel pressure for a returnless Nissan VQ35DE? In training it was stated to use 4 bar or 58 psi. The stock setup in Link and Haltech seems to be 43 psi. Which is the better one to go with on a NA motor?

Best,

Tom

The base fuel pressure needs to reflect the actual fuel pressure the engine runs or the whole fuel calculation will be skewed and the VE numbers will be unrealistic. In the majority of returnless fuel systems the base pressure is 4 bar/58 psi but that's not always the case and if in doubt you should measure it. On the other hand the link default is what you'd expect in a return-style fuel system that's manifold pressure referenced.

Hi Andre,

Thank you for the reply. It makes perfect sense. In the case of the VQ35DE, it is returnless so that would make it 58 psi? If so I would change the 43 psi in link to 58 and make fuel reference to returnless?

Which sensors would be required to convert a returnless to a return style? I know if would need to change the rails, add fuel pressure regulator and fuel pump that has a return path.

Best,

Tom

They use a nominal 350Kpa stock. 30 seconds on google found the pic below from the 350Z service manual.

"The stock setup in Link and Haltech seems to be 43 psi."

I dont know where you got that from, the Link 350Z base map uses traditional fuel equation so fuel pressure isnt even one of the available settings?