TPIS adjustable Fuel Pressure Regulator

[The Batman]

I have found a guy locally that is selling a TPIS adjustable fuel pressure regulator for $50. I have never had one in anything "modern". But is this really needed? I have a 93, and this FPR is built specifically for it. My car will likely be a cam and bolt on 355ci maybe some head work later.

[Injuneer]

Not useful unless you want to significantly raise the pressure to increase the flow capacity of the injectors, rather than buy larger ones. If you did that, you would still need a new chip burned with the new calculated flow rate.

Not useful for tuning, unless you are running an open loop tune, and even then not the best way to tune. In closed loop, the ECM will adjust the pulse widths to compensate for any changes in flow capacity, and negate the changes, until the ECM enters power enrichment mode (~WOT). Then the usual result will be to cause it to run rich.

[The Batman]

I didn't feel it was necessary for most builds. If it played a bigger factor, they would be talked about more often.

[Injuneer]

20 years ago, everyone thought they could beat the system. It was a popular mod. I remember buying an AFPR within a year of buying my Formula brand new in 1994. Once I figured out how the ECM/PCM controlled the A/F ratio, I realized I wasted my money.