When do you need to upgrade the FPR?
 

Need some help here: when should you upgrade the fuel pressure regulator? I've been searching for the answer on this but I'm getting conflicting info.

Here are my mods:
XS Eng T04E single turbo
Street ported engine
M2 Perf stock mount intercooler
Pettit stainless midpipe
Racing Beat muffler
PFC computer
stock fuel rail
stock 550cc primary injectors
upgraded secondaries to 1300cc (RC Engineering)
Nippondenso High-Flow fuel pump
B&M Newvolts Ignition Amp
RedHot plug wires
HKS spark plugs

Being that it is mainly a street car, I want to keep the boost around 15psi, which I'm thinking should get me about 380hp to the wheels. One person told me since I have the stock fuel rail, I will be fine without the fuel pressure regulator. I'm also leaning toward his opinion that it's much easier to tune the car with a CONSTANT fuel pressure (i.e. the stock FPR) instead of the complicating it with the rising rate.

opinions/personal experiences greatly appreciated
-Tom

Using RRFPRs is an inexact way of adding fuel to the combustion. It might be useful for people using FCDs, letting them run higher boost than what their ECU would normally handle. Inadequate fuel delivery is one of the reasons fule cut exists in the first place.

The correct way is to change your fuel maps. Run your injectors at the pressure they're rated for and use a duty cycle that delivers enough fuel for your application. If that's not enough, you need bigger injectors.

It's not a bad idea to install one. It is a safty measure albeit a small one.

It has it's pros and cons. It'll (normally) lower your A/FR across the board, hopefully making pinging less likely, but it's a very rough method. I guess it could be useful if you have an adjustable FPR and a wideband lambda to tune the setting.