Anyone using a rising rate FPR?

[Jspeed17]

I was thinking about this old school method for some more fuel in boost.

Running a stock MSP ECU, o2 clamp, wideband, and FCD, why wouldn't this work??? Anyone?

 

[jbrewer4639]

Look at pages 17-19 of mazdaspeedp build thread posted right above this one.

 

[BRIAN_MP5T]

Most FPR operate this way at a 1:1 ratio..

Ie, If you boost 10 PSI then the fuel pressure would be +10 over standard.

you can do some quick calculations on line, there are several Fuel Injector calculators that will let you know what the volume would be for fuel delivery.

The BEGI Rising Rate FPR is simply more aggressive... IE a 1:1.5 or 1:2 so Add 10 PSI to the manifold and add 20 PSI to the fuel rail.

(This is impractical as eventually you will kill the pump or spring a leak)

It is meant for boosing in the range of 9 PSI or less.

 

[Jspeed17]

Thank you. I appreciate the help Ya i'm looking to boost up to 15 or so, or wherever the stock turbo is still efficient.

Guess i'm going with extra injectors then. MPI baby here we go

 

[Ricktalife]

The stock turbo is efficient to about 13-14 psi. I believe most people that don't upgrade when forging just keep it around 12 because it probably doesn't do much more after that and I wouldn't want to risk hurting the turbo. Don't forget, with the extremely quick spool it produces, the stock trans may not like it too much.

 

[ajkulish]

i have a fully adjustable cartech 20005 rrfpr which is essentially the same shared technology as the begi rrfpr. though i tend to disagree with brian, that most rrfprs are more than 1:1. they are usually in the range of 8:1 to 12:1 when you are dealing with non adjustables, though mine is not set nearly that high,.

 

[BRIAN_MP5T]

I said the the stock one was 1:1

 

[Jspeed17]

So for now, until i get extra injectors, it's a good idea to eliminate the FPR solenoid and just hook to direct vacuum/boost?