Chevy and GMC Duramax Diesel Forum banner

FASS 100 vs 165 in 2021

7.6K views 5 replies 4 participants last post by  19trax95  
#1 ·
We’ve all seen the FASS vs Airdog topics or even the comparisons within the same company like the FASS 95 vs 100, but I’ve seen very little talk or comparison between the newer gen FASS lift pumps. I want to get some insight on preference or recommendation between the FASS 100 and 165.
I have a 2016 LML with efi live tuning and minor bolt on mods to allow for the best power with trans safe tunes. Stock transmission with the exception of a dummy solenoid to bump up the line pressure instead of TCM tuning. I would love to be able to build the transmission but due to the large expense that it requires, I find it to be a slim chance for me to get there. For that reason the guys at FASS push the 100gph and say that’s all I need. Many other reputable shops and businesses well known in the industry say they only push the 165 and say the 100 is a waste since the change in price is so minimal. Sounds like I can’t go wrong either way but want to hear some other thoughts on it
 
#2 ·
I believe what they are saying is the 165 will give you room to grow. I believe its good for 800hp or so, maybe more. Its one of those things where the 100 will be fine for now, a year or maybe 10 years, but eventually ull want a little more and then be stuck spending another $800 and doing the work again. If you never plan on doing anything else ever, just do the 100, but if there is the slightest chance ull do any more work, do the 165. But one thing is for sure, do one asap, get that cleaner, air free fuel to ur engine, there is not debate about that. IMO, do the 165, cuz the next owner will be happy that you did, and could be a selling point
 
#3 ·
Buy the 100 GPH model. Many people report problems with the 165 GPH model but rarely do you hear of problems with the 100 gph.
 
#4 ·
I run a fass 95 on my 15. I have a 66mm turbo, sportsman cp3 and run a pretty big street tune.

I have zero issues with rail pressure at WOT.
 
#5 ·
Is AD doing anything to eliminate or at least attempt to eliminate the 1/4 tank issue on the 15-16? I know FASS includes a larger 5/8” draw tube said to help with this issue but the issue can still happen.
 
#6 ·
I have zero issues with mine. I've purposely ran mine down u til the light came on just to make sure I wouldn't have issues and there was none. That's with the draw straw.