Maxing out fuel system, when and how do you know?
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Maxing out fuel system, when and how do you know? I've got this rig together for this year and almost finished tuning it, but it occurred to me I really don't know when I'll hit the limits of my fuel system and I don't want to find out the hard way when I'm getting close.
I have a walbro 400 in the tank and an Aeromotive FPR with Deka 80's. A 78/75 vs turbo with a summit stage 3 cam and meth injection, 5.3l.
Right now I'm running about 15lbs or boost but I was itching to go to 17 or so...not really sure its worth it or not. When will I see or get close to the limits of the 400 pump? I think the consensus was the injectors were good for over 1000 and i don't think there is a snowballs chance in hell ill actually get near that but the pump I can't find any clear info on. Most info says 600hp, but a lot of people on here and other sites say that pump is good to 800? I don't have a dyno to use so I'm stuck tuning off track times and guessing at my limits in terms of boost psi.
Am I at the end of the rope with 15lbs here?
I have a walbro 400 in the tank and an Aeromotive FPR with Deka 80's. A 78/75 vs turbo with a summit stage 3 cam and meth injection, 5.3l.
Right now I'm running about 15lbs or boost but I was itching to go to 17 or so...not really sure its worth it or not. When will I see or get close to the limits of the 400 pump? I think the consensus was the injectors were good for over 1000 and i don't think there is a snowballs chance in hell ill actually get near that but the pump I can't find any clear info on. Most info says 600hp, but a lot of people on here and other sites say that pump is good to 800? I don't have a dyno to use so I'm stuck tuning off track times and guessing at my limits in terms of boost psi.
Am I at the end of the rope with 15lbs here?
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I would assume when you start to see it lean out on it’s own your prob dropping pressure in rail. Your clearing out your fuel rail faster than pump can keep up. I had a pressure issue for alittle, my wideband would just lean out once I put a load on car. Luckily I had pressure gauge in car so was easy to tell it was that and not my base map.
how do you like running meth? I’m debating about it myself. How often do you run through it?
how do you like running meth? I’m debating about it myself. How often do you run through it?
Thread Starter
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Well ****, i guess i need an in cab fuel pressure gauge then. It's a swap into a 1984 c10 so I dont have any factory fuel pressure sensor. Maybe I should, if I can, install a factory one in the aeromotive FRP if it fits?
The meth injection is just a SnowPerformance kit with a single one of the largest nozzles. It kicks in at 8psi and goes full spray at 11psi. I run it 24/7 because all i can buy here is 90 octane. It goes through a reservoir of fluid 3-4 times per tank of gas lol. Ive played with the initial psi to turn it on running it as low as 5psi which is what the local tuner swore i would need to do, to bumping it all the way up to 10psi onset. I was playing with very conservative timing last summer when I was trying it activated at 10psi though. But I absolutely need it after 10psi or so. I had a nozzle one size smaller then too. I can't say whether I like it more than not having it though because I never ran the truck with out it. When I sorted the build out before I started I figured it would be a requirement to run the turbo here because we have nothing better than 90 octane and no ethanol fuels to speak of. But I guess I would need another pressure sensor and gauge to track that too, and can after market sensors for fuel pressures even be logged as a pid in hptuners scanner?
Does the combo it self though scream in adequate fueling?
I'm running the 80's at 42psi not 58.
The meth injection is just a SnowPerformance kit with a single one of the largest nozzles. It kicks in at 8psi and goes full spray at 11psi. I run it 24/7 because all i can buy here is 90 octane. It goes through a reservoir of fluid 3-4 times per tank of gas lol. Ive played with the initial psi to turn it on running it as low as 5psi which is what the local tuner swore i would need to do, to bumping it all the way up to 10psi onset. I was playing with very conservative timing last summer when I was trying it activated at 10psi though. But I absolutely need it after 10psi or so. I had a nozzle one size smaller then too. I can't say whether I like it more than not having it though because I never ran the truck with out it. When I sorted the build out before I started I figured it would be a requirement to run the turbo here because we have nothing better than 90 octane and no ethanol fuels to speak of. But I guess I would need another pressure sensor and gauge to track that too, and can after market sensors for fuel pressures even be logged as a pid in hptuners scanner?
Does the combo it self though scream in adequate fueling?
I'm running the 80's at 42psi not 58.
I have:
5.3 stage one cam
ported heads
vs 7875 billet
deka 80's
aeromotive 340
stock fuel system, non return
15PSI
pump 93
That one 340 isnt keeping up. I have my ve table numbers at higher boost in the mid 130's. It starts to make me ramp the fuel up (ve numbers) around 180kpa. i have not run a pressure gauge on it at wot, but i know the pressure is dropping like a rock because the ve numbers i'm using to keep up. With 60lb dekas, my duty cycle passes 100% up around 6000rpm at 14psi boost.
Your single 400 is probably right on the edge, but i think it'll take 2psi more. Mine wont, I go past 15.5 and it'll lean out. I think because you have a return you may have a slight advantage in mine. So I think you'll be ok with two psi more, log your and see. Dont make a long pull tho. You know this already i'm sure.
5.3 stage one cam
ported heads
vs 7875 billet
deka 80's
aeromotive 340
stock fuel system, non return
15PSI
pump 93
That one 340 isnt keeping up. I have my ve table numbers at higher boost in the mid 130's. It starts to make me ramp the fuel up (ve numbers) around 180kpa. i have not run a pressure gauge on it at wot, but i know the pressure is dropping like a rock because the ve numbers i'm using to keep up. With 60lb dekas, my duty cycle passes 100% up around 6000rpm at 14psi boost.
Your single 400 is probably right on the edge, but i think it'll take 2psi more. Mine wont, I go past 15.5 and it'll lean out. I think because you have a return you may have a slight advantage in mine. So I think you'll be ok with two psi more, log your and see. Dont make a long pull tho. You know this already i'm sure.
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Thread Starter
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I haven't had the VE lean out like that yet and I do hit 17psi but it only does 17psi in 2nd gear after the shift from 1st, just isn't enough load i guess before that? But it's using one of those cheap *** manual boost controllers and i have it set right now to a min base psi of 14 at its lowest setting. So going from 15 to 17 is basically just boost creep. If i use a combo of the other springs that came with the wastegate i can go from 5psi to a max of 14 but the combo that lets me go over 14psi won't go any lower than 14 as well.
I'll post my tune and the last scan i did with some heavy foot. I'm getting most of this figured out but I'm really, really new to fuel injection and boost.
I'll post my tune and the last scan i did with some heavy foot. I'm getting most of this figured out but I'm really, really new to fuel injection and boost.
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Ideally log both fuel pressure and injector duty cycle. A 400lph pump in an ideal setup may support your needs. When the filter gets dirty/restricted or pump starts to fail, volume drops, pressure drops, injector DC goes up trying to keep up. Recommended to set safety limits to save your motor. What are you using for engine control?
Thread Starter
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Ideally log both fuel pressure and injector duty cycle. A 400lph pump in an ideal setup may support your needs. When the filter gets dirty/restricted or pump starts to fail, volume drops, pressure drops, injector DC goes up trying to keep up. Recommended to set safety limits to save your motor. What are you using for engine control?
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Not that I know of, just to get fuel pressure logged i have to buy a generic 5v pressure sensor and run it through the fuel tank pressure circuit then add some custom math to the PID. The ecu is blind to it.
I think it is possible to run through the EGR circuit too...
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My injectors are at 80% at 14psi 85% DC at 17 psi and 90-95% at 20psi.
Still have a pressure sender in the mail and will hook that up to the fuel tank pressure circuit to log it but until then i still don't know FP in real time.
The AFR histogram does not show any signs of leaning out though and I'm running a 10gal/hr nozzle with like 40/60 meth/water. In fact the VE table after 170kpa gains only 3% or so all the way to 21psi the water/meth kicks on at 8psi on its gauge which ends up being the 170kpa fueling row because of the **** resolution in the 3bar OS.
Still have a pressure sender in the mail and will hook that up to the fuel tank pressure circuit to log it but until then i still don't know FP in real time.
The AFR histogram does not show any signs of leaning out though and I'm running a 10gal/hr nozzle with like 40/60 meth/water. In fact the VE table after 170kpa gains only 3% or so all the way to 21psi the water/meth kicks on at 8psi on its gauge which ends up being the 170kpa fueling row because of the **** resolution in the 3bar OS.
Thread Starter
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OK so I got the pressure sensor in and working and I guess you learn new things every day. Like 17psi is probably way to much for my 400lph pump lol.
I lose pressure at 14psi~200kpa, about 70% duty cycle on my injectors.
So i guess I'm going to turn it down to that new max and add some timing and run it for a couple days until I drop in this second 400lph pump I have here. I need to run a bigger power wire for 2 pumps, like a 10ga wire or something, its 30amps for two 400's.
I lose pressure at 14psi~200kpa, about 70% duty cycle on my injectors.
So i guess I'm going to turn it down to that new max and add some timing and run it for a couple days until I drop in this second 400lph pump I have here. I need to run a bigger power wire for 2 pumps, like a 10ga wire or something, its 30amps for two 400's.