Fuel supply and intake cooling are the key areas to address for getting maximum power out of these engines using 185mm, 61/62mm, or stacked pulleys. This thread is about FUEL SUPPLY.

The OEM returnless fuel rail system is great for reducing evaporative emissions by not returning fuel to the tank that has been warmed by the engine. Not much else is great about it. The pressure regulator is far upstream, in the fuel filter back by the tank. The fuel pressure is regulated there to the factory range of 54-60 psi. The actual pressure at the injectors could be significantly lower during high fuel usage (WOT) due to pressure drop from flow restrictions along the fuel line, through the tiny fuel rail inlet, and through the rail itself.

The looped fuel rails help to balance fuel pressure throughout the fuel rail. But they do nothing to address the tiny fuel rail inlet opening or keep fuel pressure in the rail from dropping during full throttle. The more fuel you are using, with larger fuel injectors or larger pulley ratios, the larger the fuel pressure drop problem from the regulator to the rail will be.

I need something better, so I built the Ultimate Fuel Rail.

I welded a new 8AN inlet fitting to the back of the rail centered on the vee between the left and right sides.

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I cutoff the ends of the rail and welded new 8AN outlet fittings.

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The new inlet inner diameter (ID) has 168% MORE AREA than the OEM inlet. This will flow a LOT more fuel into the rail, and maximize the fuel delivery from the fuel injectors. I considered dual inlets, but that is futile unless you need dual pumps and supply lines (alcohol/E85?) and would require buying an extra Y fitting and hose ends for use with a single fuel line.

The dual 8AN outlets will be run to an adjustable fuel pressure regulator with dual inlets. MOST AFPRs have dual inlets, one for each cylinder bank’s fuel rail. The regulated point will be AFTER the fuel rail. This eliminates the dangerous risk of running lean from fuel pressure drop at the rail when the injectors are running at a high duty cycle. It will be a true return-style fuel rail, which is tremendously better for performance and is cheap insurance from running lean and ruining an engine.

I decided to leave the OEM inlet fitting intact for future use (gauge, datalogging, etc.) or to be able to return to a stock configuration by simply installing 3 8AN caps on the new fittings. The OEM inlet fuel line will be plugged.

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If you want an Ultimate Fuel Rail modification as well, I can modify your fuel rail and ship it back to you. This winter is a great opportunity.
I can do it for $175 plus shipping.

Ultimate Fuel Rail Details: