what is the difference between the two?

 

Never heard of a fuel pressure riser but it sounds like another name for 'adjustable fuel pressure regulator'. It basically increases the fuel pressure going into the rail/injectors and is adjustable. A standard fuel pressure regulator isn't adjustable and regulates pressure at a set value.

 

I think hes talkin about a fmu

 

Forgot all about Rising rate fuel pressure regulators
Quote:

I am now convinced that this is not the proper way to address fuel management issues. Rising rate fuel pressure regulators (RRFPR) add more fuel to the engine by increasing fuel pressure as boost rises. In other words, they raise fuel pressure proportionally in response to increases in manifold pressure. Since a typical baseline for EFI fuel pressure is 38 psi or so, and these units can increase fuel pressure by 1 to 4 psi for each 1 psi of boost, they are capable of generating some absurdly high fuel pressures -- on the order of 130+ psi for highly boosted engines. It doesn't take a genius to realize that at some point, this amount of pressure will prevent the injectors from opening.

For low boost systems (<8psi), these units may make sense, especially if a normally aspirated EFI system is being converted to a turbo EFI system. For turbo systems that use more than 8 psi of boost, a RRFPR not a sound approach.

Rather than using a RRFPR as a bandaid to an underdesigned fuel management system, I am convinced that a proper match between injectors, ECU and engine demands is the only way to go. Anything short of this is an invitation to trouble.

 

fmu's =