customblackbird

iTrader: (2)

Im finishing up my turbo build/swap. Going from 10psi supercharged 5.3 to turbo 5.3. so looking at the fuel system, I dont want to run dual in tanks and I already swapped in the largest 450lph walbro to make my life easier. But when I calculated fuel flow at 12.5v It was only flowing like 250lph out of the regulator. I was running 58psi base so at 10psi it would have been at 68psi. I also run 60lb FIC matched Bosch injectors (43.5psi, or 72lb at 58psi) which should be good for 800hp.

Not looking to add another intank and I think bumping boost is going to hurt flow even more with the 450. Im starting with a 12psi wastegate spring and Im probably going to bump it up to 14-18psi. I want 650ish rwhp. So if I keep base pressure at 58psi I will be at 70-75psi fuel pressure which is high for the walbro 450. If I drop fuel pressure to 43psi then my injectors flow drops as well.

So i'm thinking of adding a 380lph AEM inline pump into the -6an feed line. That should give me a bump in fuel flow but alot more pressure. basically allowing me to run easily up to 100psi through the injector if I wanted to. The 450 would feed the 380 on the frame rail and I would set pressure to 58psi. The 380 could run all the time or I could trip it off a boost pressure switch? That way its only running in boost but that could get hairy to tune as I can set base fuel pressure with one pump off.

Thoughts?

Crf450r420

iTrader: (1)

The stock wiring can't support that pump at full capacity. You have to run a large wire to get all the flow. The higher the pressure the lower the flow will be, so if your injectors are large enough to do the job at 43 psi you will get more from the same pump that way. If you are bumping the pressure passed 3 bar to make them work it will require more fuel pump than having larger enough injectors. There are other restrictions from the rear of the car to the front that are also a factor. How many feet up from your pump is the rail as that is a load. How many 90 degree bends are there in your line? Limit your bends and use straight fittings to reduce the restrictions or go with a large feed line.

customblackbird

iTrader: (2)

couple of things I guess I needed to state. Car wiring is not stock. I ran 10 gauge from the battery to the relay by the tank, gets triggered by the PCM, 30/40 amp relay. So wiring isn’t an issue. I can’t increase fuel line size due to stock hanger, 3/8” feed hard line and 5/16” return. Tank is a stock 89 EFI tank. From the tank I have run -6 AN line to 40 micron filter then to the Billet fuel rails, then to the aeromotive boost referenced regulator and it’s returned back to the tank via -10 AN line which bottle necks to 5/16” at the tank. No way around that and it was left over from a carb build. I’m not doing anything to the stock tank and consider is mounted forever as I have had it down a few times and I’m not a fan lol hence the 450 install.

So voltage isnt isn’t an issue, bends are what they are for the install, each fuel rail has a 90 on it so like 3, one 45 and the stock hard line has like three 90s on it. No other way to run the line as it’s all space constraints.

FIC said the 72lb would support 800hp at 58psi and boost referenced. They are really 60lb but at 43psi so they are 72lb at 58 psi. At 72lb and 58psi I was seeing 69-70% Duty cycle on the supercharger in the logs I believe. So dropping tht down to 43psi would bring my duty cycle up to 80-85% at the same power level. But as you know I’m going turbo which doesn’t eat HP to make power. I was losing 50hp to the supercharger, and I was at 10psi and 70%DC. I’m going to be running min 12psi so I hope I’m up 100hp over the old
combo as I was already losing 50hp to boost + 2psi on top
of that with the turbo. I will more than likely crank it up to 14-18 psi if the injectors will let me.

So so I want to cap myself at 800hp crank so I don’t need injectors and that’s enough for the street. So if I can bump pressure to 70psi base that would help increase my injector size almost 10lb or 82lb total. That’s more than enough but the walbro won’t like that pressure and flow will decrease. So adding another pump in series will give me a small bump in flow but restore my lost fuel Pressure/flow from the walbro and high base pressures. If I’m running 70psi base pressure then that’s like 82-88psi in the rail. But the walbro wI’ll only see about half that pressure as the AEM 380 will take over the other half. I looked at a flow chart and the walbro 450 and AEM 380 flow about the same at 70 ish fuel pressure. The AEM then flows considerably more at higher pressure.

After some reading I can’t turn the 2nd pump on in boost when they are in series so it has to run all the time which isn’t a problem as long as my return line can keep the pressure down.

Crf450r420

iTrader: (1)

Unless someone has done the exact same setup of pumps and restrictions, the only way to know how much flow you will gain from it is to do it and find out. If you won't be at WOT or 800HP constantly you can push the injectors to 90% duty cycle. You are pushing the limits of those fittings now. I have the 450 in my tank and can hear the fuel returning through that 5/16" fittings. I tested it returning to a bucket and then connected to the line and didn't gain any pressure, so there is at least room for another liter per hour or two, LOL.

I have ran a pump through a pump before so I know it can be done. i don't know how it will restrict or when you'll have to signal the other pump though. I ran an MSD pump inline on my old truck and had it only come one when I armed the two stages of nitrous. Ran it that way for a few years, about 35,000 miles. I didn't know you couldn't do it, so I did it because it worked.

customblackbird

iTrader: (2)

Thanks, Yea I assume I'm not getting the max out of the 450 but I knew that with the stock 3/8" hard line. Thats why I think 2 pumps in series would work best for me as I can increase pressure without affecting max flow volume too much. I read that you shouldn't turn off the 2nd pump if the 1st is running... the 450 should push through the 380 as it will just act like a restriction when off hopefully. The issue is that the pressure increase of the 2nd pump (380) that could result in a huge bump in fuel pressure when turned on. I could test this I guess so its not that big of a deal. Basically test fuel flow in current config, then add 2nd pump and leave off, then test fuel flow (not changing regulator setting so I can see pressure change), then turn 2nd pump on and see fuel flow and pressure changes.

Ive been itching to remove the summit -6an braided pressure line to swap out to a rubber pushlock as I'm sick of the fuel smell coming from the braided line. But that means I need new hose and fittings = more $$.

So whats stopping me is my 450 might be enough in my setup, I dont want to finnish and then have to jack the car up 2ft to get under it and do all this **** again. Or I just say screw it and do the series and hope it works. I also dont want to upgrade the system and not have enough return line and have issues. Otherwise I would have to redo the lines and remove the 2nd pump Unless I run the 2nd up in the engine bay since it doesnt need to be gravity fed.

Crf450r420

iTrader: (1)

I would think you would get the most out of it by having the second pump up front in the engine bay. That is how I had it. That way the tank pump is doing the work to get up front. Then the second pumps little bit of suction helps it and adds all of it's push right before you need it.

Mine did bump the fuel pressure up when I turned on the second one, my guess was the stock truck regulator not designed to handle that much. Also, I just tuned the nitrous to be right and let it run a little rich on motor (which wasn't long). On your setup with a better regulator, if the pressure does go up with the second pump coming on, try it again with the return into a fuel jug. That will let you know if it's the reg or the restrictive return line causing it. If it's the return line then just raise your reg pressure so it already runs that high.

customblackbird

iTrader: (2)

I think I agree with you.

I don't think my regulator is going to be an issue, its a aeromotive bypass style designed for carb and EFI and has a 250 GPH rating. But the 5/16" return line at the tank is not rated for that lol. So that might be what I do.

I figured out I have the 267 walbro 450lph pump so its not the high pressure version which means relief valve opens up at 80psi. So I can't run more than that with just the walbro 450. My other option is I just leave the 450 alone and keep fuel pressure below 60psi and hope for the best. All the online calculators Ive looked at show 700 crank HP is good for a 60lb injector at 43.5psi with a .65 BSFC and up to 90% duty cycle. I've also read that on pump gas the 450lph should support 800whp as long as the pressures don't get that high.

So do I leave the pump alone and just see what it will do? Or so I swap out my 40 micron and drop $140 on the AEM and wire it up and see what it will do.

I'm looking to place an order with summit like tmrw and trying to decide what I want to do ugh lol. I will be out of the state till next week. I was also looking at getting some Taylor spark plug wires and getting some LS coil boots just in case my turbo headers which are wrapped (and have spark plug boot heat sleeves) decide to melt and than I got problems. I don't want to spend the money on the pump if I'm not going to run it, and I don't want to buy the plug wires if I don't need them bc they are 350ohm/ft and I currently have 25ohm/ft so they are much better!

Old Geezer

iTrader: (3)

"So voltage isnt isn’t an issue".
It is, if the voltage at the pump is only 12+.

Crf450r420

iTrader: (1)

It's hard to be sure, so best way to do it is to try and see. You might have to go back in, but most projects have trials to figure it out.

Sounds like if all is right you can set it to 58psi and you might make it to up to 12 psi boost on the 450 alone. Walbro rates it at 750+. I'm aiming at 800 with it, but the 150 nitrous takes less fuel than on motor.

Crf450r420

iTrader: (1)

Did I read 40 micron filter? Where is that filter? You need a 10 micron before the injectors or you will end up with issues at some point.

customblackbird

iTrader: (2)

voltage is not an issue. I was testing flow of the pump with the engine not running. I had a charger on the battery on a 10 amp setting and it couldn’t keep up with the pump so voltage stayed around 12.5v. Next setting on the charger was 50amps and it would click on and off bc the pump wasn’t draining enough. Without the pump the battery gets to 13.7 on the charger at 10 amps. But I get the full 14.4v at the pump when I test it with a meter with the engine running. But I was testing the fuel system through the regulator and I can’t have the engine running with that.

edit: alt is a powermaster 170amp and it puts out about 110 at idle and doesn’t get below 14v even with both fans on and headlights.

customblackbird

iTrader: (2)

yup, 40 micron right before the fuel rails. And the walbro has the 100 micron sock on it. I didn’t run a 10 micron bc they don’t use reusable filters... and I’ve pulled and cleaned the 40’micron a few times which looks like a brownish flake that turns to mush in your fingers. I know a 10 is better but I can’t clean that crap out and they are $$ to keep replacing.

G Atsma

By doing that you are letting particles in that are big enough to mess up your injectors. Pony up for the 10 micron and save some headaches. You have been lucky so far...

customblackbird

iTrader: (2)

Yea Ive always know that but never wanted to deal with replacing filters. I have placed my order! Among that was the summit brand billet 10 micron filter and a replacement filter element $80 later

I also got the AEM 380 for a whopping $123 and I got an -10 to -6 adapter for the pump inlet. I have a spare -6 an to -6 straight cut in my box o fittings. I'm not sure if I should just plumb it up with the AEM 380 inline and then make that section removable?

Figured It would pump the walbro 450 intank to the AEM 380 which then pumps through the 10 microns filter to the fuel rail, then back to the regulator and back to the tank. I could make a secondary fuel line to run from the PUMP + filter just in case it doesn't work out I can just swap the old stuff back except get rid of the 40 micron and leave the longer 10 micron.

Crf450r420

iTrader: (1)

That $80 for the 10 micron is about what it cost to have 4 injectors cleaned, so it is saving you money in the long run.

Sounds like you have a plan of attack and only way to figure out what is really going to happen is to do it. Good luck. Also, just because you have a restriction at the tank doesn't mean increasing the hose everywhere else won't help. Get to a large size as early as you can before the fuel rails to slow the velocity down at the injector inlets and good luck.

customblackbird

iTrader: (2)

Got the pump and filter today. Both look fine, the AEM pump showed up and looks like its soaking in like 4oz of machining oil. ITs in a bag thats in a bubble wrap bag and its filled with oil. I wonder if I need to clean it out somehow?

Thinking it might be a good idea to test flow through the pump and see if I can maintain fuel pressure with it off. Then test with it both on and see if it affects fuel pressure enough to warrant a no go or to just leave them both on all the time. Basically if I run it at 58psi and then kick on the AEM pump and pressure shoots to 70psi then I can't use that since my PCM will have a set injector size. In which case I have to have both on all the time which is fine and adjust pressure for both pumps.

Crf450r420

iTrader: (1)

The oil is probably what they use to test the pumps as a part of QC

You will have to test this setup to see how or if it works off and if your pressure will maintain.

35spline

iTrader: (1)

Why not? This one of the options I have under consideration.

Crf450r420

iTrader: (1)

Only reason I can think of is he doesn't have something that allows that control, nothing else stopping him. I'd figure at the least you could figure out the earliest RPM that boost would be hit and use a shift light control or something. Be better than running both all the time and heating the fuel more.

customblackbird

iTrader: (2)

the only thing keeping me from doing it is 2 reasons.

1.) the fuel pump in the tank has to pump through the dead AEM pump all the time, this would obstruct flow and affect pressure that the pump would not see normally. I’ve read it is also bad to be pushing fuel through a non working pump. To drive the “restriction” aspect further... the AEM pump comes with a -6 to -8 check valve fitting to keep fuel from coming back to the pump. This check valve although tiny and is on the pressure side EXIT of the pump causes 2% loss in fuel volume according to AEM. It has been tested and real world is that it reatricts fuel flow ALOT more. This is a simple check valve... imagine pumping through a non working fuel pump.

2.) there is no way for you to manage fuel pressure with the 2nd pump on. Say you set fuel pressure at 58psi with the intake pump working with 60lb injectors, so you set the PCM injector data for 60lb injectors. Now you keep the 2nd pump off untill boost, boost hits and the in-line pump turns on and now your pushing more fuel instantly and a lot more pressure. Your 58psi base pressure is wayyy off now and your PCM injector data is no longer accurate. I think you would see a huge spike in fuel pressure with the 2nd pump
on manly bc of the loss in flow from the dead pump and then when it’s activated the restriction is no longer present and now the pump is pushing even more. So your fuel pressure regulator is off and if you push a 58psi 60lb injector to say 73psi that injector now flows 72lb. That’s a large bump in flow. Basically what I’m trying to say is that you can’t adjust the fuel pressure to compensate for the 2nd pump and change the data in the PCM.

If you guys have better ideas im all ears! I have the pump but haven’t installed it as I’m waiting to test the 450 to see if it can keep up.