Years ago we discovered the flow limits of the HPG1 fram filter while running our engine fuel, and nitrous system fuel from the same source.

Now we run the Mallory Comp500. Cannister type dual -8 inlet and outlet which works great with my favorite pump, the Dominator series Volumax 250 georotor which features a dual inlet and single outlet. The Mallory filter is 40 micron. It's an excellent upgrade from the HPG1.