I am thinking of getting a Fass or Fass II. What would be the advantages or disadvantages of one vs the other. I know Fass II uses the stock filter. Would this be a bad thing?
Issopro gauges on order, hope to install this week

Alan

 

I see no big disadvantages to the FASS II. If it was around when many of us needed more fuel, I'm sure we would have gone that route. No problems using factory fuel filtration...it has been a trouble free element.
Biggest advantage to the FASS I is 3/8" lines and no restrictive banjo bolts, all the way to the Injector Pump, for more fuel flow...but that does not become important until you start adding serious HP....and can be handled at that time.

The FASS I will allow better fuel filtration...down to 5 microns; even 3 microns, if you want. (factory filter at 10 microns).

I'm not convinced the water separator works any better than the factory system...just don't know for sure?

If money is not a big concern, the FASS I is the nicer unit.

Whichever way you go, the 95 gph pump is all you will need. It's quieter and flows plenty of fuel for up 600+ hp. Even towing heavy...or racing, the CTD won't comsume more than 8-10 gph, leaving plenty of fuel for pump cooling, etc. I'm not sure if the larger pump is available in the FASS II anyway?

Good Luck!

RJ

 

They have both a 150GPH and a 95GPH in the HPFP (FASS II) and the FASS. The 95 is what probably 90% of the general public needs. The 150GPH might cause fuel cavitation issues with the stock fuel sending unit in the tank. BUT DPP is addressing this issue with some bulkhead fittings and such for the future. Like Rjohnson said, the stock filter housing is fine. AND you can upgrade the line between the filter housing and pump to 3/8's if needed via part number - BBRK-1001. That should flow plenty. I see the FASS having an advantage in fuel filter size. I would venture a guess around 3 qts worth of filter media between the filter and water separator. The separator filters down to about the 40ish micron level. This would allow you to run about 30K before changing the filter. (Sooner with smaller micron filter).

You do gain some power with the FASS 1...though nothing to jump up and yell about....but my truck idled noticeably quieter and smoother after the one i put in my truck.

BUT the main benefit of the FASS (1 or 2) is positive fuel pressure that wont fade with load. Your pump can only accept soooo much fuel...but i would like to have more pressure/volume than too little.

 

i just put a fass2 on this weekend and i was seeing 16psi at idle before this pump and now im seeing 23 at idle and cant drag it under 19 . humm i guess its time to tap the wire and put bigger injecters in to releave some of that fuel pressure . the biggest reason i went to this pump was im sick of changing out lift pumps the stocker was doing the hocky pocky on me again and well now i have a 4 year warntey so for the price you cant beat it . plus i dont know if its just me but i think it idles quiter than before. maybe all that extra fuel quited it down.

 

Thanks for the help on the FASS.

Alan