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Filter before Lp

Hate it when the truck is calling but the house has priority. Good to see you’re back on the motor though. Looked good.

Not sure which lift pump you want from Kennedy but, his “same as the the one we sell for the duramax” is listed at 4psi. I looked it up on his Duramax offerings since his 6.5 advert is low on facts. Here’s a screen shot as I’m sure I can’t post the link and have it stick.
IMG_0186.jpeg
Wow, $195 for 4 PSI and you can double them to get 6-7psi for only $395 (wiring extra). Yes, I know, Duramax systems are much different etc.
Don’t know what the “universal LP” is rated at but, doubt it’s much more than the AC Delco. Might as well hit up Leroy or another vendor of choice for the (my pref.) AirDog with the water and 2 micron filter. Save some plumbing for the Pre-Filter and you could ditch the FFM at the same time.

Transmission lines, Built my own using transmission fluid/diesel fuel rated braided steel and did the -6 AN conversion. Or, scavanger hunt from a parts yard.
 
Thanks guys for the input. Yes I did see that pump on there site. Didn’t think it would be that low. Wasn’t thrilled about having to prime the pump if it loses its prime. Quadstar use to sell a different one it had its own bracket and used the oem line fittings. Might have to pull the trigger and buy one of the big boy pumps. Unfortunately already have a new FFM and a pre filter kit from Leroy’s. Does any body have an opinion on installing the feed the beast kit ( Leroy’s) on a new FFM. Wondering if that mod. Would keep up the fuel press. on WOT? Thanks again guys.
 
FTB helps with fuel flow. It is what should have been done from the beginning.
But getting a pressure gauge tapped at the ip via metal fitting is more crucial imo so that you know when things aren’t right before damage is done.

imo the reason GM reduces the size is to artificially bump up the pressure. Boyles law says when the volume of flow stays the same but the pile size decreases, the pressure will rise. Why else would they run 3/8 from tank to ffm then reduce at that point from ffm to ip…

Now if the pressure is brought up from 6-8 pei with stock pump to 8-14 range with a better pump, this will automatically increase the volume of flow to get it done. So leaving 5/16 and getting the pressure into the proper range will have a better effect than leaving the same undersized pump snd increasing volume,
But understand everyone that has ever increased the size (FTB) notices improvement.
We were doing this in the fleet when these trucks were new and drivers who didn’t know anything we did would ask- hey did you turn up my turbo, hey did you turn up my computer, etc. we didn’t do it exactly the sane way as FTB mod is shown on this site, but had same concept.
 
Thanks Will, I will be putting a fuel press. gauge under the hood and also in the cab. I’ve had pretty good luck on the OEM LP never failing. What I don’t like is in the past the fuel press. was reading 1 to 2psi at the gauge sometimes. I already have a new FFM and pre filter. I’m going to try FTB mod and see where the psi is at WOT. Has anybody had trouble drilling out the orfice holes under the screen at the IP inlet? Carbide tip bit? If I don’t like it it’s the big boy pump for me. Is the Raptor LP an open on fail pump?
 
The orifice holes are in hardened metal but not so hard as to be undrillable with regular drill bits. Keep the rpm down and have a spare bit handy.
The raptor is not flow on fail but I'm not to worried. I hooked my to the factory fitting so I could use an oem LP if needed. I had to make the output side fitting. Might be something available but I couldn't find it.
 
Goose57 said:
Thanks Will, I will be putting a fuel press. gauge under the hood and also in the cab. I’ve had pretty good luck on the OEM LP never failing. What I don’t like is in the past the fuel press. was reading 1 to 2psi at the gauge sometimes. I already have a new FFM and pre filter. I’m going to try FTB mod and see where the psi is at WOT. Has anybody had trouble drilling out the orfice holes under the screen at the IP inlet? Carbide tip bit? If I don’t like it it’s the big boy pump for me. Is the Raptor LP an open on fail pump?
Click to expand...
FWIW, My experience is that fuel pressure at WOT drops to Zero using the OEM LP w/ Feed the Beast mod. That’s why I decided to go back to my AirDog DF series which is a Flow on Fail set up.
 
Goose57 said:
Thanks guys for all the good info. What is the Air Dogs LP psi at the IP?
Click to expand...
Newest edition of AirDog 5G-100 and 165 models are pre-set at factory to 8-10 psi. Mine is an older 165 and min. pressure is also 10 psi. It can be increased to (can’t remember or find) but, unnecessary as it doesn’t drop under WOT.

Quadstar sells the 5G version, Leroy’s advertised unit is the older FP-100 w/o the upgraded 4G motor. “If you want the upgraded “4G motor” version of this kit email me for an invoice. They are available also. They have a quieter motor and an “on demand” type pump.” The FP is about a $100 less than the 5G.
 
Paveltolz said:
Newest edition of AirDog 5G-100 and 165 models are pre-set at factory to 8-10 psi. Mine is an older 165 and min. pressure is also 10 psi. It can be increased to (can’t remember or find) but, unnecessary as it doesn’t drop under WOT.

Quadstar sells the 5G version, Leroy’s advertised unit is the older FP-100 w/o the upgraded 4G motor. “If you want the upgraded “4G motor” version of this kit email me for an invoice. They are available also. They have a quieter motor and an “on demand” type pump.” The FP is about a $100 less than the 5G.
Click to expand...
Thanks Paveltolz. I think I’m going to get the the new motor in and get it fired up with the OEM pump (already have it) and FTB mod.first.
See where I’m at w/ the fuel pressures.
 
Happy to help with info. I did the same after getting the engine sorted out and installing a new tank. Left the sock on the sender (still there), OEM LP was fine in commuter traffic, aftermarket 2 micron filter just before the IP vs. the FFM and continued 3/8” to the IP inlet. It will give you time to save some $$ for the upgrade later too.
It wasn’t until I started roadtrips that I got concerned about the sustained low pressure while ascending grades.
Keep us posted. I’m curious about the difference of pushing through the 2 micron aftermarket set up vs. the FTB modified FFM.
 
Paveltolz said:
Happy to help with info. I did the same after getting the engine sorted out and installing a new tank. Left the sock on the sender (still there), OEM LP was fine in commuter traffic, aftermarket 2 micron filter just before the IP vs. the FFM and continued 3/8” to the IP inlet. It will give you time to save some $$ for the upgrade later too.
It wasn’t until I started roadtrips that I got concerned about the sustained low pressure while ascending grades.
Keep us posted. I’m curious about the difference of pushing through the 2 micron aftermarket set up vs. the FTB modified FFM.
Click to expand...
Will do. Thanks.
 
Paveltolz said:
Happy to help with info. I did the same after getting the engine sorted out and installing a new tank. Left the sock on the sender (still there), OEM LP was fine in commuter traffic, aftermarket 2 micron filter just before the IP vs. the FFM and continued 3/8” to the IP inlet. It will give you time to save some $$ for the upgrade later too.
It wasn’t until I started roadtrips that I got concerned about the sustained low pressure while ascending grades.
Keep us posted. I’m curious about the difference of pushing through the 2 micron aftermarket set up vs. the FTB modified FFM.
Click to expand...
If I remember right I was getting 2 micron filters for the FFM. I think I posted about it, years ago
 
On 2 micron vs 5 micron (factory)- the type of LP you run can have a major impact.
Unless you are spending around $200 per filter, you are not getting an ABSOLUTE rated filter. Meaning 100% of anything that size gets stopped. Almost all filters are rated as NOMINAL.
A filter rated “95% nominal 5 micron” means it catches 95% of everything larger than 5 microns. The rest goes through it to your ip, injectors, and whatever bypasses the injectors goes back to the tank.

The ‘bigboy’ LP systems have a direct feed that when more fuel gets pushed than the ip can process, there is an additional return hose that goes back to the tank. When talking the amount of fuel say the FASS system processes through its filters and the 6.5 rig is just normal driving, this makes A LOT of fuel just get recirculated back to the tank. And if the FASS filter is 5 micron nominal and so is the GM FFM, what’s the big deal?

You pump in 20 gallons of dirty fuel into your tank. And the GM LP/FFM gets it all once. Gets maybe 10% of it twice. (Kinda high estimate but for sake of argument let’s pretend it is that high). Gets maybe 1% of it a third time. Then it is time for you to fill up and add in 20 gallons of dirty fuel again.
You went from 5 dirt to 0.5 dirt to 0.05dirt…

FASS or Airdogg with their filter and that LP pushing massive quantities more through and your ip and injectors still see the same amount. But now the LP is shoving 10 times the amount of fuel through those annoyingly large filters. And they have to be that large to handle the volume of fuel going through or they would tear inside. What is happening to the fuel is: 5% of the 5 microns gets through, 0.5, 0.05, 0.005, 0.0005, 0.00005, 0.000005, 0.0000005, 0.00000005, 0,000000005
Now you finally go buy that next 20 gallons of dirty fuel.

Running the nicer LP that has ample flow and pressure to keep the ip happy is one part of the equation. And while my example above isn’t exactly accurate it should show you why diesels that run these systems have so much less problems than ones with just enough to not break down too often systems- aka get you through warranty systems.

I know fuel engineers who go to the gas stations and pump fuel into bed mounted transfer tanks. Then drive home and pump it from that tank into barrels in the garage where it gets ran through the big annoying filters for a day, back and forth between two barrels. One guy has timer on his to auto shut off. Another just lets it run until the next day when he turns it off himself. Then they pump that “polished” fuel into their trucks. Neither of those guys live here in Vegas. We don’t have humidity, so almost no rust in the gas station tanks. But when they moved to humid areas of the country they invested. They also run the big boy LP on their trucks for insurance.
Over the top? Check.
Use the filters for tracking information at their jobs? Check.
Get high miles from their fuel systems in their trucks? Check. —
Over 700k in a 01 dmax for one guy- original injectors…hmm.

So what does better- two passes at 2 micron, or 20 passes at 5 micron?
There is a reason I keep telling people invest in the big boy stuff.

I have db2. They are a dime a dozen. On my 6.5 pickups I have ran straight used motor oil. When the smoking got bad, it was time to pour water into the intake and remove carbon. When the ip and injectors were cooked (hard hot starts) I just spent a few hours and $75-100 for a used ip. I rebuilt the injectors ahead of time and slapped them all in. Now abuse it some more. The db2 went in the scrap bin and who cares because there is millions more to be had for next to no cost.
There is extremes on both ends.

You gotta figure what investment is worth it to you. The expense of a ds4, the added nonsense of what it takes replacing one (komputer/timing), hard to get parts to rebuild injectors now, etc- I just don’t understand how not having these set ups on the truck is near standard now. This simply wasn’t an option back in the day. But we also didn’t have to fight some evil villain nonsense like algae that can live inside of fuel. Our fuel was a lubricant, it didn’t need lubricant added to it.

I am “chicken little”. I over build. I rather not do something than do it half way anymore. Take this into account when considering my opinions. But because I’ve done enough to learn all that I have, consider my opinion is all I say.
If you have the money to let your truck blow up on a Tuesday and your Wednesday can continue as planned - the roi might not be there for you. If your world comes to a halt on that Tuesday afternoon to the point you will loose sleep that night wondering what to do tomorrow…
 
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