Fuel system discussion

White_monster · Jun 4, 2012

delong_1 said:
Have you guys watched lift pump pressure during a hard run? Just a though, my smaller pump wouldn't maintain, moved up to a 200 and now it at least maintains a few psi during a full power pass. Something to consider.

You make an excellent point. I wonder if this is why I can maintain rp on a high mile pump with 60's due to me running Elites stage 2 low pressure fuel kit. The a1000 moves almost twice what the ad165 does. Maybe that's why even at 2.29pw I still hold rp.

blk350on20s · Jun 4, 2012

The reason for turning up the ad is so at WOT its getting as much fuel. Yes at idle and light use it will return more fuel but when needed its pumping the psi there. Thats the way i look at it. Im running in the teens on my fass.

pog · Jun 4, 2012

blk350on20s said:
The reason for turning up the ad is so at WOT its getting as much fuel. Yes at idle and light use it will return more fuel but when needed its pumping the psi there. Thats the way i look at it. Im running in the teens on my fass.

im pretty sure turning up the psi on the ad doesnt flow more fuel.

blk350on20s · Jun 4, 2012

More pressure to me would be flowing more fuel. Am i lost?

pog · Jun 4, 2012

it was slightly discussed in this thread
http://powerstrokearmy.com/forums/showthread.php?t=17579&highlight=airdog&page=2

blk350on20s · Jun 4, 2012

Interesting. Thanks for the read

78f100 · Jun 4, 2012

Some good info there, that is what I was getting at more pressure doesnt always mean more flow. Its kinda like a pressure washer you have large volume of low pressure water in and small volume of high pressure out. The hpfp is the same way but there has to be a sweet spot for inlet pressure and return pressure. Just like the pressure washer no matter how much pressure the water hose has after a certain point the pump can only take in so much.

Tree Trimmer · Jun 5, 2012

i dont know how the fuel system on a 6.4 is routed. keep in mind, i come from a 7.3, and im assuming, really, the only difference is the addition of a hpfp. have looked at some schematics of the fuel system, and thats my take on it.

turning the pressure up in the ad, means all the flow is goin through it. there is no return from the ad. meaning any volume produce by the ad, goes to the hpfp.

this is where my slight confusion will take place. im assuming the secondary regulator is on the return of the system. this is the regulator that will determine system pressure. you do not want this regulator, and another, to "share" the job. this is why wayne told you to max the ad regulator.

the system is goin to return through the lowest regulated port. if its the ad, even intermittently for whatever reason, then you have fuel not even making it to the hpfp. it is the, aeromotive in your case, then 100% of fuel flow is goin past the hpfp, and it can drink as much as it wants, and spit the rest out.

my understanding of it, should be something like this. tank, ad, fuel bowl(or not for some people), hpfp, aeromotive, return.

not tank, ad/return, fuel bowl(or not for some people), hpfp, aeromotive, return.

i get that right?

78f100 · Jun 6, 2012

Treetrimmer that makes perfect sense, I didnt think of it that way. Your correct though if the ad is wide open then the aeromotive reg will do all the pressure regulating. I just need to figure out why it surges the hpfp when I max it out. I will turn the ad back up and try only tuning the aeromotive reg and see what happens. If that doesnt help guess I will bite the bullet and go duel pumps.

09stroker · Jun 6, 2012

Basically the HPFP is at the "Dead End" of the system. So whatever the last regulator is set at should be the inlet pressure. Therefore the first regulator (on the air dog) should be set higher to supply ample flow. Any extra fuel would simple bypass through the regulator back to the tank to regulate pressure. Doesn't matter if not all of the fuel from the pump goes the the HPFP as long as the inlet has the proper supply pressure

78f100 · Jun 10, 2012

I fixed my issue holding 24,300 to 25,000 now at wot, turns out my rails were leaking. I replaced them with new stock ones, will never put ported rails back on. It also fixed the surge/shutter at 55-60mph.

Dzchey21 · Jun 10, 2012

78f100 said:
I fixed my issue holding 24,300 to 25,000 now at wot, turns out my rails were leaking. I replaced them with new stock ones, will never put ported rails back on. It also fixed the surge/shutter at 55-60mph.

Wonder what's up with the rails leaking?

78f100 · Jun 10, 2012

Idk, I am the 3rd that had the same problem that I know of, I don't think the end caps were torqued properly. It sucks

Super08Duty · Jun 10, 2012

does anyone know what the end cap torque specs should be? i can test that theory on my ported rails.

Dzchey21 · Jun 10, 2012

I've never seen a spec as they really aren't to be serviced

Kind · Jun 10, 2012

I've maintained 25,000, 2.2 ms pw, custom tune from Mike at KEM. All stock fuel and air. The tune he wrote me commands max psi but no way it will go that high. But I have gotten short spikes over 26,000 almost 27,000. When it did go above 26,000 it would drop back down to the high 23,000's but right back up to 25,000. Gonna try this tune with the new set up. If I can find the data log from this tune that I sent Mike I will post it. Downside to this tune on stock air is it maxed out the egt gauge almost instantly. On nitrous it pulled way harder then anything I've had with this truck but also maxed out egts fairly fast.

pog · Jun 10, 2012

Kind said:
I've maintained 25,000, 2.2 ms pw, custom tune from Mike at KEM. All stock fuel and air. The tune he wrote me commands max psi but no way it will go that high. But I have gotten short spikes over 26,000 almost 27,000. When it did go above 26,000 it would drop back down to the high 23,000's but right back up to 25,000. Gonna try this tune with the new set up. If I can find the data log from this tune that I sent Mike I will post it. Downside to this tune on stock air is it maxed out the egt gauge almost instantly. On nitrous it pulled way harder then anything I've had with this truck but also maxed out egts fairly fast.

just wondering.. did you have him make a custom tune for more power on intake+exhaust+tune setup?

Kind · Jun 10, 2012

pog said:
just wondering.. did you have him make a custom tune for more power on intake+exhaust+tune setup?

Yeah, it's based off his 345 tune. However it's not a tune I'd recommend because it gets so hot so quick, even in a little truck like mine.

blackmonster · Jul 18, 2012

What about the River City cp3 set up? Still supposed to have 14psi and 26,000 rail. They have one stock pump and one mod duramax pump. What do you guys think about this sys? The Elite lines were leeking on my truck and Craig can't get the high pressure lines. He ordered them almost 1month ago and still nothing and no return phone calls. What do you guys think? Cp3/River City Diesel the way to go. Anyone tried this sys?