To increase the volume of fuel flow to your Fuel Rail there is a Banjo Bolt (driver side of rail) that needs the cross drilled hole reamed to the same size as the body I.D (.235"/5.969mm). .

Relieve the fuel pressure from the fuel line according to the manual.
Remove the Banjo Bolt located on the driver side of the fuel rail. The Banjo Bolt on the passenger side has double cross drilled holes and this modification is unnecessary.

Once the banjo Bolt is removed there is a Compression washer on the bolt, or it may be sticking to the fuel rail, DO NOT lose these washers. If you do not reinstall this washer, reassembly will result in a Gas leak which is extremely HAZARDOUS.

If you have lost the washer, here is the Part number.
Mazda part # N236-13-483 (description is, Gasket).
You can get one at your local Mazda Dealer.

Clamping the Banjo bolt in a vice by the Hex head, Drill the cross hole to .235" diameter (5.969mm).
DO NOT drill any larger than suggested in these instructions. This will weaken the bolt and it may break upon reassembly.

When you are done matching the hole sizes, debur the Bolt and clean thoroughly.
Reassemble the fuel rail and Banjo bolt.

When I did this I noticed an increase of fuel pressure on my Paxton FPR. The pressure went from 43psi to 45psi with no adjustment made to the FPR.
At WOT, FPR pressure rose 4psi higher than it has prior to the modification of the Banjo Bolt.
I then reset my FPR to 43psi.(I am using a stock fuel pump.)