what is the minimum acceptable fuel pressure inorder for fuel injectors to function properly, assuming that there will not be an issue with pressure drop at high flow rates.

 

FSM for an S4 N/A says....

Regulated pressure is 35.6 to 37 psi.

Fuel pump outlet pressure is 64.0 to 85.3 psi.

On the S5 FSM for an N/A....

Regulated pressure is 34.1 to 39.8

Fuel Pump outlet pressure is 64.0 to 85.3.

Hope this helps.

 

Why would you want less pressure than stock?

 

I think OP my be asking because he is testing FP on his car?

Could be wrong though. Low fuel pressure isn't good. Too high isn't good either.

Get' er just right.

 

I was asking because i am trying to figure out how to run on ethanol and i need to buy a fuel pump. I was just seeing if i could get by with a pump that that puts out a whole lot of fuel but at a 35psi. All the high pressure (70psi) pumps that are alcohol safe are really really expensive.