New gen FASS pumps: 100 vs 165

[KRATOCT]

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

 

[Chevy1925]

Do you understand what the numbers mean between them? Regardless of the generations between them, it’s still just a difference of flow.

You will never use more than the 100 can provide at your level.

 

[KRATOCT]

I do understand the flow specs yes. What I don’t necessarily have the answers to is any ill effects of circulating too much fuel due to it not being needed/used. Possibly excessive recirculating resulting in unnecessary heating of the fuel or additional air being introduced to the fuel? Possibly other things to consider.
Maybe there is no downside to running a pump pushing more fuel than needed within reason. At that point, for a difference of $30 on a $700+ unit, why even make a pump with a lower flow rate than the common 150-165gph? Most people running lift pumps have some basic mods anyway. Just curious.

 

[Chevy1925]

I do understand the flow specs yes. What I don’t necessarily have the answers to is any ill effects of circulating too much fuel due to it not being needed/used. Possibly excessive recirculating resulting in unnecessary heating of the fuel or additional air being introduced to the fuel? Possibly other things to consider.
Maybe there is no downside to running a pump pushing more fuel than needed within reason. At that point, for a difference of $30 on a $700+ unit, why even make a pump with a lower flow rate than the common 150-165gph? Most people running lift pumps have some basic mods anyway. Just curious.

supply vs demand. if everyone understood the gph for their need, they would be buying the 100 more and the 165 would be much higher.

fuel return is all done through the pump and yes you will be adding more heat to the fuel but the 100 wont be saving you much on that side.

the 100 is great for the small dmax 4 and 6 banger engines.

 

[Bdsankey]

Honestly you can't go wrong with either. I sell a ton of both. Most of my LML customers go down the AirDog route as they have a demand flow system meaning the pump only draws what's required which helps on the LML's suction side.


Long story short, IMO you can't go wrong with FASS or AirDog. 100gph is more than you'll ever need unless you plan on making big power with it later on (built motor etc).

 

[gmduramax]

Don’t the filters only flow like 25gph or something ridiculously low?

 

[ZeroGravity58]

I don't know about flow but you can switch to a better filter. I run a donaldson filter and baldwin water separator. The airdog filters arnt the best, Donaldson filters are 2 micron. I also don't run a factory filter on either of my trucks

 

[DuramaxRamRod]

Don’t the filters only flow like 25gph or something ridiculously low?

25gpm

 

[KRATOCT]

Honestly you can't go wrong with either. I sell a ton of both. Most of my LML customers go down the AirDog route as they have a demand flow system meaning the pump only draws what's required which helps on the LML's suction side.


Long story short, IMO you can't go wrong with FASS or AirDog. 100gph is more than you'll ever need unless you plan on making big power with it later on (built motor etc).

Brad does this scenario of Airdog having an advantage over the FASS on the LMLs still apply when comparing AD to the newer LML specific FASS pumps? I heard their newer kits when selected for the proper year truck (I have a 16) have the larger draw tube that eliminate 1/4 tank or 1/8 tank issue and a lot of reputable shops well known in the industry that are aware of this are pushing FASS hands down over AD. I called a few popular shops that carry both and most have changed my mind from AD 165 to FASS 100 or 165 saying the technology with the titanium series is better and with the 5/8 draw tube there’s no need for a sump. Happy to hear more input here. I know both will do the job but rather than hearing that most of the shops I called said FASS. Thanks

 

[Bdsankey]

Brad does this scenario of Airdog having an advantage over the FASS on the LMLs still apply when comparing AD to the newer LML specific FASS pumps? I heard their newer kits when selected for the proper year truck (I have a 16) have the larger draw tube that eliminate 1/4 tank or 1/8 tank issue and a lot of reputable shops well known in the industry that are aware of this are pushing FASS hands down over AD. I called a few popular shops that carry both and most have changed my mind from AD 165 to FASS 100 or 165 saying the technology with the titanium series is better and with the 5/8 draw tube there’s no need for a sump. Happy to hear more input here. I know both will do the job but rather than hearing that most of the shops I called said FASS. Thanks

It comes down to what you like. I am personally a FASS fan but again, you can't go wrong with either. I think FASS has a better motor, better filters, and more cross-references for filters while you're on the road.

 

[MN2500HD]

Is FASS demand flow?

I went with the AD 165 because of the demand flow feature on a 2004 LB7.

I thought I read FASS was a constant delivery?


Sent from my iPad using Tapatalk

 

[Bdsankey]

FASS is not demand flow like an AirDog. The FASS makes full flow and returns whatever isn't used back to the tank.

 

[Ne-max]

Fuelab, Fleece, or Airdog Raptor with stock filter would be my vote. FACTORY FILTERS work just fine.

 

[gmduramax]

No love for Kennedy diesel any more?

25gpm

That makes more sense now lol

 

[ZeroGravity58]

I used kennedy pumps in two trucks. They were great, only reason I went away was they were a PITA to bleed. Any time I changed the filter I had to push air down the filler neck to force fuel into the filter to bleed the air out since they weren't self priming.

 

[NC-smokinlmm]

Fuelab, Fleece, or Airdog Raptor with stock filter would be my vote. FACTORY FILTERS work just fine.

I completely agree, I would still run the extra filters though. My Airdog 165 saved me from asphaltine contaminated fuel once and that was worth the extra money for me.

 

[PureHybrid]

I used kennedy pumps in two trucks. They were great, only reason I went away was they were a PITA to bleed. Any time I changed the filter I had to push air down the filler neck to force fuel into the filter to bleed the air out since they weren't self priming.

Where was your filter mounted?

I've had Kennedy twin pumps on mine since 2011, only had one problem last year. Pump wiring was fried on one. Took all of 10min to swap the pump and solder new wires

 

[KRATOCT]

I am fairly new to the demand flow technology in the AD pumps mentioned above. Is this supposed to aid in reducing or eliminating the 1/4-1/8 tank issue? And how effective is the new draw tube with the FASS in solving this problem? This is my main concern. I know otherwise these are both good pumps. I prefer not to go the sump route

 

[2004LB7]

What is this 1/4 tank issue you speak of? Is it the gauge saying empty, then when you fill up it's full before the fill tank capacity, meaning you didn't use up all the fuel before the light cam on? Or is it running out of fuel / engine dieing when it still says there's fuel in the tank?

I don't see how a larger pick up tube or demand flow technology is supposed to change any of those. First is the scaling of the fuel level sensor in the tune or a bad sender. The second is normally from a cracked puck up tube or the venturi fell out.

The stock pick up can draw almost all the fuel from the tank. Sumps are when you want to get every last ounce or you are making huge power and need the extra flow. Otherwise the stock pickup is great for most and can still support pretty high HP

 

[ZeroGravity58]

I had my pump and filter mounted on the outside of the frame right where the fill neck is on both trucks. The pumps are awesome, nice and quiet.