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Fuel Pressure Diviation Limits

Practical Dyno Tuning

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In my experience on turbocharged engines fuel pressure (FP) under boost does not stay at 1:1 with manifold pressure. Fuel pressure is typically 5-10 psi behind manifold pressure. I find myself having to increase the VE tables in order to match targe lambda.

What is an acceptable threshold limit for fuel pressure? When setting FP sensor input as an engine protection threshold I find myself adjusting the dead band value to a larger window.

Jose G.

Does your ECU have a fuel pressure compensation? You can use that to handle the cases when the regulator / fuel pump are a bit behind the demand.

I am using the Elite 2500 with ESP on an RB26. I have not seen where the fuel pressure compensation table is, I'm sure it is as simple as creating a generic table. However, what is the normal/acceptable deviation limits for this drift in fuel pressure?

It's late, so I'll get back to this tomorrow - but in the interim, is this a fuel return regulated system, or a 'dead head' that is regulated at the pump and has no return? From what you say, I suspect the latter?

It is a conventional return style system from the 90's with a regulated return. I have witnessed the same thing on multiple vehicles, a 4G63 engine and currently experiencing the same thing on an R32 GTR.