Fuel management

[Wakkolio]

If you are to get something like a emanage or a safc would you need a new fuel pressure regulator?

[SingleCamSam]

No. But an FPR never hurts if your trying to feed alot of boost.

[95_240sx]

The stock FPR on the DE's work great, I feel that the aftermarket rising rate FPR's are a waste of money.

Just my 2c

Rick

[Mikel]

The stock FPR on the DE's work great, I feel that the aftermarket rising rate FPR's are a waste of money.

Just my 2c

Rick

I feel you're wrong. There's a reason that the vast majority of factory turbo cars have a rising rate regulator.

[Sil240]

adjustable fuel pressure regulators are not a waste of money bc if you want more fuel without buying new injectors then it helps and the stock one you cant turn up it is just set and boost sensitive regulators (1:1ratio)are even better b/c for every 1lb of boost you go it raises the pressure 1lb

[C-Kwik]

This post is a bit confusing. Either some of you are using the wrong terminology or are mistaken about what the items you are describing really are.

FPR is just a fuel pressure regulator. It can be stock, Aftermarket adjustable 1:1 Aftermarket x:1, or Aftermarket Adjustable x:1. The term isn't specific.

An adjustable FPR allows you to adjust the base fuel pressure, but still rises at a 1:1 rate.

A Rising rate FPR refers to a boost dependent FPR or FMU.

As far as which one is best to use or if at all depends on your preferences. A rising rate FPR is a cheap way to get more fuel when boosting. *To Rick* - I wonder if you've even tried using one. For the cost, nothing beats it. It of course has limitations, but within those limits, it works great.

An adjustable 1:1 FPR can be used to feed more fuel, but requires retuning the ECU or running a piggy back. You can certainly run a high fuel pressure so that the fuel requirements are met under full boost, but since the fuel pressure is fixed, it will run very rich at all other times.*Sil240:* Stock FPR's also rise at a rate of 1:1. Actually, any 1:1 regulator will regulate pressure in reference to manifold pressure so that it is always a certain set psi over the manifold pressure.

Rising rate FPR is what you use to surpass the stock injector's rated max flow rate. Since it increases fuel pressure more as you get more boost. Most people and kits use a 7:1 or 8:1 RRFPR which is good for up to about 6-7 psi.

Lastly, to answer Wakkolio's question, it depends. If you are using stock injectors, then yes. An AFC or E-Manage will not give you more maximum fuel if you are already maxing it out. With larger injectors that are sufficient for the boost level you are running, no, you won't need a RRFPR.

[Wakkolio]

Thanks C-Kwik. I am going to use 720cc injectors. I have also decided to go with a SDS standalone system. I figure it will be better choice than to go with a piggyback system and using MAF.