Fuel System Upgrades

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The stock '94-'95 fuel pump flows 87lph of fuel and supplies eight fuel injectors that flow 19lb/hr each at a fuel pressure of 39psi (vacuum disconnected from fuel pressure regulator).
The stock 19lb/hr injectors flow a total of 129lb/hr of fuel at the maximum recommended 85% duty cycle. That's just about enough to supply the 275fwhp that you'd get with "stage 1" performance upgrades (cold air intake, larger diameter MAF housing, larger bore throttle body, underdrive pulleys, headers, midpipe, catbacks, 1.7 ratio roller rockers). Beyond 275fwhp, it is advisable to either raise the fuel pressure with an adjustable fuel pressure regulator or install higher-flowing injectors.
The stock 87lph fuel pump can supply a maximum of 143lb/hr of fuel which is enough to feed 300fwhp. An upgrade is necessary to prevent a higher rpm lean condition under WOT when anything beyond mild upgrades to the heads/camshaft/intake manifold are planned.

Walbro 190lph fuel pump

A 190lph fuel pump will supply a total of 310lb/hr of fuel, which is enough for a supercharged engine producing ~550 flywheel HP. No risk of fuel starvation in my engine!

BBK adjustable fuel pressure regulator

This blue anodized BBK adjustable fuel pressure regulator (BBK-1707) installs onto the rear of the fuel injector rail and is a direct replacement for the stock non-adjustable fuel pressure regulator. It has an adjustment range from 35-70psi and the fuel pressure can be raised by turning the Allen hex screw clockwise after loosening the locknut. With the aid of the Kirban fuel pressure gauge, I set the fuel pressure at 45psi with the vacuum pipe disconnected from the regulator.

Installation instructions.

Kirban fuel pressure gauge

This liquid-filled Kirban 0-100psi mechanical fuel pressure gauge (KP-1441) kit screws directly onto the Schrader valve of the fuel injector rail making installation very simple.