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I'm swapping out my aeromotive 340lph for a walbro 450lph. What mods need to be done to fit in the stock bracket? Do you just remove the stock bottom bracket on the return line for the pump?
Does anyone have any install pics?
I thought about keeping the 340 and using the stock tank vent line for that and re-purposing the evap line as my new vent. What do you guys think of that? I know the stock evap line has that vent valve on the sender... so not sure how that will work as a plain vent.
I wish i could chime in on this one but mine is currently on a carb tank setup. I just made it work. Seems to work fin unless you are under a half tank :s. Im swapping to an LS1 tank as soon as I can get my car fired up and spun around in my garage. So close do doing so.
Thanks! Yea I figure I'm going to have to figure this out. I just hope I dont overpower the stock 5/16" fuel line at the tank.
I would love to do a LS1 tank, but I would opt for the billet sender that allows custom AN line routing... not cheap tho but no messing around with the factory stuff.
Thanks! Yea I figure I'm going to have to figure this out. I just hope I dont overpower the stock 5/16" fuel line at the tank.
I would love to do a LS1 tank, but I would opt for the billet sender that allows custom AN line routing... not cheap tho but no messing around with the factory stuff.
I ended up just buying the bolt on adapters to adapt to -8an and -6an for a stock sender.
TORN: here is some specs I compiled between the 340 and 450 pumps I had posted on ls1tech.
My Data logs suggest 525-550hp at the crank at 70psi fuel with 72lb bosch injectors. The new combo can make 650hp+ at the same boost and fuel pressures. The Aeromotive 340 only flows enough to support 580hp at 70psi vs the 845hp the 450 can support. My only concern is the fuel pressure short section of 5/16" return line. I have thought about running lower 43.5psi as my base fuel pressure but FIC recommended I dont as the LS1 style 72lb bosch injectors have a much better spray pattern at 58psi.
Ah I miss read that. I already knew about these fittings. Personally I would love to upgrade the stock sender to a 3/8" return. Which you can't do with just an adapter fitting. Thats where the billet aftermarket pump hanger comes into play.
I received my 450lph pump yesterday. No way it will fit the stock bottom hanger area If I remember it correctly. Also the pump install kit doesn't include submersable fuel line to connect the pump to the stock line. So be prepared if you do the swap to pick up your own hose. I'm going to see how much hose I have left from the Aeromotive pump I got.
TORN: here is some specs I compiled between the 340 and 450 pumps I had posted on ls1tech.
My Data logs suggest 525-550hp at the crank at 70psi fuel with 72lb bosch injectors. The new combo can make 650hp+ at the same boost and fuel pressures. The Aeromotive 340 only flows enough to support 580hp at 70psi vs the 845hp the 450 can support. My only concern is the fuel pressure short section of 5/16" return line. I have thought about running lower 43.5psi as my base fuel pressure but FIC recommended I dont as the LS1 style 72lb bosch injectors have a much better spray pattern at 58psi.
I"m running 72lb/800cc Bosch EV14's at 35psig base fuel pressure in my project with a Stealth 340 in the tank. They still flow just over 68lbs at that pressure and that gives you tons more fuel flow from the pump, and I have had no tuning issues running that low a pressure (I've tried as low as 30psi with no problems to confirm another problem that I had wasn't an issue caused by the low fuel pressure).
I figure if I run out of fuel I'll drop fuel pressure first, and if i"m still out I'll drop the Walbro in, which shouldn't be that much work on my setup (LS1 tank, modified bucket/hanger/access hatch...)
I"m running 72lb/800cc Bosch EV14's at 35psig base fuel pressure in my project with a Stealth 340 in the tank. They still flow just over 68lbs at that pressure and that gives you tons more fuel flow from the pump, and I have had no tuning issues running that low a pressure (I've tried as low as 30psi with no problems to confirm another problem that I had wasn't an issue caused by the low fuel pressure).
I figure if I run out of fuel I'll drop fuel pressure first, and if i"m still out I'll drop the Walbro in, which shouldn't be that much work on my setup (LS1 tank, modified bucket/hanger/access hatch...)
I was told by John at FIC that I can run my LS1 60lb injectors at 43.5psi and they would be fine, didnt recommend lower than that and also stated that at 58psi the spray pattern was much better compared to the 43.5psi. They are 60lb rated at 43.5psi and at 58psi they are 72lb. I could drop the fuel pressure to increase pump flow but the injector output then suffers. No real way around it I guess even tho Im sure its fine at 43.5psi since fuel pressure drops a good bit when vacuum is high anyways.
I wont cut the floor up as i have the 3rd gen tank, but if I had an LS1 tank it would be easier. Honestly tho... I hope to never have to pull the tank again.
well I installed the 450lph pump yesterday. Pump swap took about an hour, luckly the aeromotive 340 used the same electrical plug as the walbro so once I pulled the wires down alittle more (walbro was like 1/2" shorter in the wiring) it plugged right in.
Other notes on the install, the walbro does not fit like a stock pump, also the inlet is MUCH smaller than the 340 on the bottom of the pump. I find it odd that the pump inlet was so small compared to the aeromotive and the aeromotive uses a SS screen there to catch anything if the filter pops off. The Walbros base is much larger than the 340 and thus the bracket doesn't really cradle it. The bottom of the pump also isn't lined up with the hole in the bottom for the prefilter. I used all the stock isolators and I was able to get the pump filter on through the bottom like stock buts its tight. the pump seemed taller due to it not falling into the bottom cradle as much as the stock style 340 and the top of the pump basically was right up against the metal feed tube. Other than that it went right in and I used an extra SS worm clamp to keep it in place.
When I tested it, it seemed quieter than the 340 alittle. At 12.2-12.5v with a 10amp charger on the battery it pumped out 1.25 gallons in 1 min. which is only 284lph at 0psi which seems very low compared to the 413lph or 109gph that its rated at. This is through the stock 3/8" hard line at the tank and then -6an after. I'm going to check my 40 micron inline filter and verify its clean which it should be.
I was told by John at FIC that I can run my LS1 60lb injectors at 43.5psi and they would be fine, didnt recommend lower than that and also stated that at 58psi the spray pattern was much better compared to the 43.5psi. They are 60lb rated at 43.5psi and at 58psi they are 72lb. I could drop the fuel pressure to increase pump flow but the injector output then suffers. No real way around it I guess even tho Im sure its fine at 43.5psi since fuel pressure drops a good bit when vacuum is high anyways
I don't know what to tell you, you can take the generic answer that you need more pressure to get it to atomize correctly (sort of makes sense but the fact is that on and off there have been applications that have run standard injectors at much lower pressures, and TBI injectors have been run at everything from 8 to 25psi from the factory. I can tell you for sure that I'm running those injectors at 35psi RIGHT NOW, and have run them as low as 30psi and haven't seen any issues, and I'm MUCH more **** retentive about these things then most people here, I just don't stick to the "right answer" according to rumor...
I wont cut the floor up as i have the 3rd gen tank, but if I had an LS1 tank it would be easier. Honestly tho... I hope to never have to pull the tank again.
You know, you are running into exactly the reason why these cars should have had a hatch from the factory, and the reason I put one in. Cutting up the floor like many of the disasters posted here is the wrong thing to do, cutting up the floor and putting in a properly reinforced hatch is the right thing to do (unless you're building a concours restore of a 3rd gen, and I have no freaking idea why anyone would do that).
If you ever do put in a 4th gen tank and follow a lot of the information here (which is wrong about venting...) I can guarantee that you'll be pissed off when you have to pull the tank a second time to fix your plumbing...
Did you ever consider a boost a pump for the 340lph? That big a pump your choking it with the stock sender and stock lines. Did you ever have trouble keeping the fp down with the 340lph?
If you ever do put in a 4th gen tank and follow a lot of the information here (which is wrong about venting...) I can guarantee that you'll be pissed off when you have to pull the tank a second time to fix your plumbing...
Do tell.... I've done 2 4th gen plastic tank swaps and never had any issues. Curious to see what others are doing wrong. I wont give away my method
5/16" short section at the sending unit is not really a problem. If you are using the fuel at wot theres little to worry about returning. I ran triple 255's thru it on a -6 return but wasnt returning much fuel at the 1100+ hp mark. And at idle or part throttle, the regulator if a good one will be handling the pressure. Alot of basic regulators have some small passages thru them. You'd be surprised lol.
Now that 3/8" outlet of the sending unit is a problem at the 1050+ wheel hp range...needs to be bigger for big hp. But for 1000 and less its no problem on gas
Those AN adapters to the tube line on sending unit are awesome. Work great.
If you did a triple, then a double will fit for sure. Some guys tie into the voltage feed line in the cabin. I ran a 10 gauge from there to the back off the alt for power. I know the racetronix wiring upgrade for the top hat is a bit bigger. They supply everything from the pump to the connector above the rear end. And I tied a 10 into there back to the motor. When I bought mine from racetronix the 340l they warned against using the stock harness in the tank.
Did you ever consider a boost a pump for the 340lph? That big a pump your choking it with the stock sender and stock lines. Did you ever have trouble keeping the fp down with the 340lph?
Unless your shooting for a quadriple digits I would think the 340lph would be sufficent.
Alot of tests have been posted on the 340 showing how much it will support.
3 things. but no never had a problem keeping 58psi base pressure (no vacuum) or something like 45psi with vacuum at idle.
1.) I posted independent flow rates of the aeromotive 340lph pump in this thread. The issue is the base pressure plus the 1:1 boost pressure puts me around my target hp and thus it may be sufficent but why risk it. Since I was removing most of the exhaust to do a muffler swap I figured it was a good time as 50% of the work was already done. The 70psi fuel pressure Im seeing the pump can't technically keep up. I'm estimating 650hp at 70psi fuel pressure. Unless i crank down the fuel pressure to 43.5 and plus 12psi fuel pressure puts me at 55psi which is right around my target HP. But thats running the pump at the max. Pumps output degrades over time just like any electric motor device. So either way an upgrade would be in order. FWIW the aeromotive 340 can only support 958hp at 0psi or free flow at ideal conditions. Even carbs run at 5-9psi which the aeromotive can only support 920-885hp.
2.) How are the stock lines choking it? The pumps output is same if not smaller than the 3/8" feed line it connects to. Basically the same as the aeromotive 340. the Walbro 450 basically just adds a second set of impeller blades to increase flow over the 340 and it pulls alittle more amps. But reading on the interwebs states that the stock 3/8" feed and 5/16" lines found on almost all the new camaros etc all support 1000hp. As Orr stated... most fuel regulators use very tiny return port sizes in the regulator itself so the 5/16" line is not really a restriction when compared to that.
3.) boost a pump is not recommended for anything over 255lph on the internal tanks. The 340 and 450 pull something like 18amps and the boost a pumps can't keep up.
5/16" short section at the sending unit is not really a problem. If you are using the fuel at wot theres little to worry about returning. I ran triple 255's thru it on a -6 return but wasnt returning much fuel at the 1100+ hp mark. And at idle or part throttle, the regulator if a good one will be handling the pressure. Alot of basic regulators have some small passages thru them. You'd be surprised lol.
Now that 3/8" outlet of the sending unit is a problem at the 1050+ wheel hp range...needs to be bigger for big hp. But for 1000 and less its no problem on gas
Those AN adapters to the tube line on sending unit are awesome. Work great.
This is everything Ive been reading.
Stock 3/8 and 5/16 lines have supported up to 1000hp without issue. All the new Copo camaros run stock fuel lines and the new mustangs etc. The tube size can be compensated with more fuel pressure. Theroetically a -6an or ID line can support 1200hp and be fine.
Alot of the fuel regulators for EFI applications us a 1/8" return port hole in the diaphram area. You would be suprised when you opened it up and saw that, yet they can still bleed enough pressure to maintain constant pressure.
My Aeromotive regulator is a HIGH flow dual purpose (carb and EFI) with a simple spring swap. The return port in the regulator is MASSIVE as its designed to control 250GPH high flow low pressure pumps. If I had to guess the return port in the regulator is close to 3/8" ID
My setup only uses stock lines at the tank due to the 3rd gen design and difficulty getting AN lines installed in the stock sender. Once after the tank I run -6 feed line and -10 return which gets reduced back to 5/16" at the tank. this was the setup I ran with my sumped tank and holley dominator external fuel pump.
If you did a triple, then a double will fit for sure. Some guys tie into the voltage feed line in the cabin. I ran a 10 gauge from there to the back off the alt for power. I know the racetronix wiring upgrade for the top hat is a bit bigger. They supply everything from the pump to the connector above the rear end. And I tied a 10 into there back to the motor. When I bought mine from racetronix the 340l they warned against using the stock harness in the tank.
With a 255 pump the wiring upgrade is a good idea, with a 340 the upgrade is a must, same as the 450. I ditched the stock stuff and run 10 gauge to the trunk and then 14 gauge to the pump. I use the stock connector for the sender and ground but the pump gets its own pos and neg 14 gauge wiring. The 340 and 450 pull alot more amps than a 255.
Some pics of the install.The wiring provided with the 340 and 450 is the same, same gauge and plug. So mine simply swapped out. If I had to guess the gauge is 14 and thats what I used to connect to it from my relay in the trunk.
Last edited by customblackbird; 03-02-2017 at 09:49 AM.
Ive read the 340s run 750 -850 hp at 40 psi. Now you got me wondering why your running 70psi. I missed that. Why not run a bigger injector? I should have cleared up the choke part in terms of lines. 6an is fluid in size, tad bigger than 3/8 and consistant unlike factory bends.Cant compare line size to new stuff though. Most of the new stuff is dead head with no returns. Dont know about the camaros but have seen these on other cars. The 70psi is why not many pumps will keep up that pressure. Can your ecu handle different injector size?
With a 255 pump the wiring upgrade is a good idea, with a 340 the upgrade is a must, same as the 450. I ditched the stock stuff and run 10 gauge to the trunk and then 14 gauge to the pump. I use the stock connector for the sender and ground but the pump gets its own pos and neg 14 gauge wiring. The 340 and 450 pull alot more amps than a 255.
Did you buy a kit with fuel rated sheath wiring? Or buy the connector specifically for the sending unit? Did you run wiring into the tank yourself?
Pump flow drops with pressure. You need to boost reference the regulator in forced induction to keep the same delta fuel pressure to manifold pressure you'd see in a na car
Trick is balancing total fuel pressure with boost and flow for the hp at the voltage the system runs at.
Supply line size increase can deliver volume at lower pressure and saves the pump a bit. Its harder on the pump to get the volume required thru small lines at high pressures.
Larger injectors are the way to go but then you gotta watch out for injector opening/closing times to make sure you can get them to behave at idle and part throttle. This is only a problem on small cube motors making big power that need big injectors. Alot of todays high flowing injectors are pretty well mannered at low pulse widths
In your case OP, you have a -10 return. That is way oversized. Rather see that as the supply line but even then its large for gasoline. -8 can make over 1200 wheel hp on gas. -6 returns are typically all you need. -8 or larger is for carb cars, maybe methonal/e85 stuff or belt driven super high flow mechanical pumps
TORN: here is some specs I compiled between the 340 and 450 pumps I had posted on ls1tech.
My Data logs suggest 525-550hp at the crank at 70psi fuel with 72lb bosch injectors. The new combo can make 650hp+ at the same boost and fuel pressures. The Aeromotive 340 only flows enough to support 580hp at 70psi vs the 845hp the 450 can support. My only concern is the fuel pressure short section of 5/16" return line. I have thought about running lower 43.5psi as my base fuel pressure but FIC recommended I dont as the LS1 style 72lb bosch injectors have a much better spray pattern at 58psi.
Ive read the 340s run 750 -850 hp at 40 psi. Now you got me wondering why your running 70psi. I missed that. Why not run a bigger injector? I should have cleared up the choke part in terms of lines. 6an is fluid in size, tad bigger than 3/8 and consistant unlike factory bends.Cant compare line size to new stuff though. Most of the new stuff is dead head with no returns. Dont know about the camaros but have seen these on other cars. The 70psi is why not many pumps will keep up that pressure. Can your ecu handle different injector size?
you are correct, at 40psi the 340 will support 750hp but at 50 psi that drops to 700hp and at 60psi that drops to 640psi. So I would be limited to 48psi max base fuel pressure to clear that threshold. As Orr stated my base fuel pressure is 58psi, same as a stock LS motor. So at WOT on a NA LS motor the fuel pressure would be 58psi. Due to boost (12psi) my effective fuel pressure would be 58psi-12psi or 46psi since the boost is pushing the fuel back into the rails at 12psi. Which is why I run a boost referenced regulator at a 1:1 ratio... basically 1psi =1psi more of fuel pressure. So at 12psi boost (or 12 atmospheres) the fuel is still being injected at the normal 58psi.
My injectors aren't an issue. 60lb at 43psi or 72lb at 58psi. At 58psi the 72lb injector is capable of supporting 800hp. I dont need anymore injector and at 550hp ish I was only seeing 60-70% injector duty cycle. When you increase fuel injector size you stuck with minimum pulse widths and usually you can have issues with idle and low RPM tuning once you reach a certain injector size. I wont ever see 800hp, I also need this thing to idle at 550-600rpms like a champ. My 0411 pcm can support any injector size and fuel pressure. I will probably mess with different injector pressures and possibly leave it at 43.5psi, but going to leave it as is for now.
The 99 5.3 and most of the early LS motors had a return style regulator on the intake manifold. I pulled mine off so I know it had it stock. The later (newer) LS motors have a return setup in the tank or back by the tank... it still circulates the fuel but technically from the regulator to the rails its a dead head system.
The wiring is fuel rated and came with the fuel pumps. fuel rated wire is very expensive normally.
Thats where I got my data from. Look at the charts closely. I have them printed out in front of me and I have calculated on them the flow vs HP ratings. If you knotice in that link that the BOSCH 044 actually flows more starting at 55psi compared to the 340. The 340 says 500lbs/hr at 40psi and thats only 315lph... not 340lph. WEll technically its 306.8lph at 500lbs/hr. That would mean that a 340lph pump at 40 psi needs to actually flow 554.18lbs/hr of fuel. The 340 does not put that out at 40psi according to that chart. I would suspect that it flows 340lph free flow at 0psi but not at 40psi.
You should use a HP fuel calculator to figure these things out vs just listening to someones speculation.
Please see the attached screen shot.
In order to make 650hp at 58psi I need 227lph at 58psi (no boost)
The same as above but with 12psi boost I need 273lph at 70psi maybe its due to increased pressure as well as a richer A/F mix.
The 340 according to that site shows:
60psi = 428lbs/hr = 269lph = 768hp NA capable
70psi = 390lbs/hr = 245lph = 700hp NA capable
Going by the chart on that site... the 340 should support 747hp at 30psi boost at 40psi... which is the same as 58psi base plus 12psi = 70psi. So somewhere the math got alittle screwy but it would have been still too close for comfort. Plus factor in other restrictions etc I would rather error on the safe side.
Another thing is that my 450lph only pumped 284lph roughly at 12.2V which is much lower than advertised. This is due to low voltage but also probably other restrictions.
I didnt verify the numbers with my calcs but you sound like you are on the right track for numbers.
My own example, twin 255's at 64-65 psi total pressure flows about 208 lph each, or 416 total. That was good for 1034 hp std 1009 sae whp, estimated 1175-1200 crank hp. So basically a 255 pump at 58 psi is good to 600 hp each.
By that figure 315 lph would be good to 900 crank but sounds optimistic to me.
Aeromotive 340 charts i see are 280-290 lph at 58 psi at 13.5 v. Thats 800-840 hp
If volts drop you are even less hp
I like big gauge wire off the alternator for pump power. Aka hotwire kit
You should use a HP fuel calculator to figure these things out vs just listening to someones speculation..
Im sorry who was I listening too? I have two 340lph in 2 diff cars. I called , talk to them they told me what they flow at what psi. Aeromotive rates the max flow at 40psi as does Raceteonix own purple version. Most cars run base 40 psi.Im kind of perplexed . I was questioning the use of 58 psi injectors. You are saying the company told you the injector you are running needs to be run at 58 base psi. So I guess you have too.Most pumps are not going to flow much near their advertised psi over 50psi. I would say instead of using injectors that need to be at 58 psi base use ones rated at 40psi and the 12 psi delta increase boost refereced gives you some breathing room. Asking any pump to do 70psi and more when you up the boost is going to be a chore. Your running methanol too so that has to be factored in. Obviously there is a problem if a 450lph pump is only flowing 270lph. Is the intank 450lph a genuine walbro? Just asking because there are alot of fakes floating around. Looks like double or triple intanks are probably what you need.
So, putting aside all the variables, let’s presume the best case scenario: What maximum HP could a 340 Stealth pump support if the system were fully optimized?
Okay, in a bypass EFI fuel system that has been optimized to include:
a 72 lb/hr injector (presuming V-8 engines, 150 lb/hr for 4 cylinder engines)
40 PSI base fuel pressure, vacuum line disconnected
Boost is limited to 20 PSI (allowing a 1:1 boost reference to 60 PSI max under load)
Providing the system has the necessary electrical supply to properly power the pump
An appropriate fuel line size equivalent to AN-06 is installed
A high-flow filter such as Aeromotive 12301 is installed
A decent, high flow fuel rail is employed to feed the injectors
A high flow regulator such as P/N 13109 and a AN-06 return line is present
It would be reasonable to rate the 340 Stealth to 700 flywheel HP EFI forced induction, 900 flywheel HP EFI naturally aspirated, on gasoline fuel. In this example the injector duty cycle for either V-8 or 4-Cyl would be between 80-85%.
Just a copy and past from Aeromotives site. So maybe add a second one and be done with it. If your worried about the factory sender size to eliminate any issues there are companys out there that will upsize the senders lines. I personally have a bigger feed and return line. -6an both.
In this case if the job can be done with 1 pump, go 1 pump lol the 450 works well. Pump failures are somewhat rare but you'll hear alot of them on the net for 255/340 pumps. Not sure why. But if you have 1 pump and it fails, engine shuts down. If you have 2 pumps and 1 fails, engine melts down
In this case if the job can be done with 1 pump, go 1 pump lol the 450 works well. Pump failures are somewhat rare but you'll hear alot of them on the net for 255/340 pumps. Not sure why. But if you have 1 pump and it fails, engine shuts down. If you have 2 pumps and 1 fails, engine melts down
I said this same stuff in the "twin fuel pump thread" and y'all said i was crazy..
Don't get caught up in the whole spray pattern thing. it's basically meaningless on anything we are running. Our intakes, our valve angle are all against us. Even if you had an ECM and your cam specs programmed in to inject fuel at the exact time, fuel will be bouncing off stuff and tumbling out of suspension anyway.
The LSx motors are a little better, but the newer direct injection stuff is where spray pattern actually matters.
So the question is why 58psi is better than 40psi?
Cuz it looks better on the asnu machine
Every motor is different, but the majority of us are spraying fuel on a hot closed intake valve, and the fuel atomizes then.
Some of us have injector angles that spray at the floor of the runner.
I've always run stock fuel pressure, a 1:1 rise. Better off anyway in a boosted application, because as pressure goes up volume goes down. You want to try to stay in the sweet spot as much as possible with the pump.
I said this same stuff in the "twin fuel pump thread" and y'all said i was crazy..
-- Joe
Noone said you were crazy but that dudes build was a bit different. He had a 408 ls motor that would be capable of making the power of a single 450 pump. Didnt want to have to change out at a later point when and if he decides to turn the car up
It would have worked fine for where he was currently but down the road thinking it made sense
Every motor is different, but the majority of us are spraying fuel on a hot closed intake valve, and the fuel atomizes then.
Some of us have injector angles that spray at the floor of the runner.
I've always run stock fuel pressure, a 1:1 rise. Better off anyway in a boosted application, because as pressure goes up volume goes down. You want to try to stay in the sweet spot as much as possible with the pump.
-- Joe
Makes sense. Most pumps are rated at 40psi and drop off considerably after that. Wondering why blackbirds pump, the 450 is outputting so low.
Makes sense. Most pumps are rated at 40psi and drop off considerably after that. Wondering why blackbirds pump, the 450 is outputting so low.
Quote: Another thing is that my 450lph only pumped 284lph roughly at 12.2V which is much lower than advertised. This is due to low voltage but also probably other restrictions.
Im sorry who was I listening too? I have two 340lph in 2 diff cars. I called , talk to them they told me what they flow at what psi. Aeromotive rates the max flow at 40psi as does Raceteonix own purple version. Most cars run base 40 psi.Im kind of perplexed . I was questioning the use of 58 psi injectors. You are saying the company told you the injector you are running needs to be run at 58 base psi. So I guess you have too.Most pumps are not going to flow much near their advertised psi over 50psi. I would say instead of using injectors that need to be at 58 psi base use ones rated at 40psi and the 12 psi delta increase boost refereced gives you some breathing room. Asking any pump to do 70psi and more when you up the boost is going to be a chore. Your running methanol too so that has to be factored in. Obviously there is a problem if a 450lph pump is only flowing 270lph. Is the intank 450lph a genuine walbro? Just asking because there are alot of fakes floating around. Looks like double or triple intanks are probably what you need.
Dont take this as an attack... its not.
You have to take what people write or "claim" with a grain of salt. Sure Aeromotive wants to sell you a pump, they are going to tell you what you want to hear. Ive had ALOT of Aeromotive parts over the years and can't say all lived up to what they say. My A1000 sounded like a damn space shuttle and had all the internal wiring blocking the exit fuel port. There 340 stealth pumps are made in CHINA. Independent tests are always the BEST and thus provide real unbiased results. I can tell you that the aeromotive 340 pumped less fuel than this walbro 450 does in my setup. Mainly because I haven't changed anything but the pump and had to test both pumps and drain the tank. I would say the 450 pumped at least 1/3 more gallon of fuel than the 340 in the same time. So for me to see a 315lph flow rate at 40psi when aeromotive is claming 340lph then I would tend to believe the independent test more so.
Why do you say "most" cars run 40psi? Most cars (nothing built in the last 20 years runs that low a fuel pressure for the most part. If anything fuel pressures are only INCREASING. I can't remember the Lt1/LT4 fuel pressure but All LS motors for the last 18 years run 58psi base fuel pressure. I dont know much about imports etc but the fact that basically all GM chevy motors have been running higher fuel pressure than 40psi the last 20 years or so. Not to mention the new DI is 2500psi. Old school fuel injection ran 37-43psi but that was before they were able to design better fuel injectors and pumps. Two things happen when you lower fuel pressure, First you loose flow (through the injector), second you loose spray pattern/misting/atomization abilities. Now I'm not saying that you cant get a good spray pattern with a 43psi injector but a 58psi injector will have a better pattern. I dont have to run 58psi, I can run 43psi but 58psi is alittle better. I actually have lowered my fuel pressure to 44psi and will see what it does after changing it in the tune.
Pump is a genuine TI walbro 450lph... got it from summit racing, install kit is genuine as well. I like knowing that my 450 is made in the USA at least so I'm glad to get that china 340 out at the very least. I have also since testing the flow removed my 40 micron filter and inspected. The filter was pretty clogged with what looked like brown flakes or something. Wasn't rust or metallic so it might have just been some **** that was in the line from fuel evaporating etc. I have blown the filter out and cleaned it and installed everything. I have lowered fuel pressure to 44psi and will edit the tune to reflect that.
Last edited by customblackbird; 03-06-2017 at 11:56 AM.
So, putting aside all the variables, let’s presume the best case scenario: What maximum HP could a 340 Stealth pump support if the system were fully optimized?
Okay, in a bypass EFI fuel system that has been optimized to include:
a 72 lb/hr injector (presuming V-8 engines, 150 lb/hr for 4 cylinder engines)
40 PSI base fuel pressure, vacuum line disconnected
Boost is limited to 20 PSI (allowing a 1:1 boost reference to 60 PSI max under load)
Providing the system has the necessary electrical supply to properly power the pump
An appropriate fuel line size equivalent to AN-06 is installed
A high-flow filter such as Aeromotive 12301 is installed
A decent, high flow fuel rail is employed to feed the injectors
A high flow regulator such as P/N 13109 and a AN-06 return line is present
It would be reasonable to rate the 340 Stealth to 700 flywheel HP EFI forced induction, 900 flywheel HP EFI naturally aspirated, on gasoline fuel. In this example the injector duty cycle for either V-8 or 4-Cyl would be between 80-85%.
Just a copy and past from Aeromotives site. So maybe add a second one and be done with it. If your worried about the factory sender size to eliminate any issues there are companys out there that will upsize the senders lines. I personally have a bigger feed and return line. -6an both.
Quote: Another thing is that my 450lph only pumped 284lph roughly at 12.2V which is much lower than advertised. This is due to low voltage but also probably other restrictions.
Low volts. Give it 13.5-14 off the alt
Agreed. I stated that when I flowed the pump The issue is that the pump pulled more than 10amps, on the charger my battery was only capable of maintaining 12.2v with 10 amp charger. If i set the charger to 50 amps it would have been kicking on and off the charger and skewed the results even more. I would need a 20-25amp charger on the battery to get a 13+v battery while on the pump.
Even with that being said the only real restrictions would be the stock fuel line size at the tank. After that its all -6AN hose and high flow fittings. But I did find my filter was a bit clogged so that would affect flow slightly and walbro rates the pump at 12v and 13.5v. Specs below.
flow up to 30/40psi shows no real pump losses with the 450 as well as no real increases in Amps either. But I am down a estimated 130lph compared to the 413lph free flow at 12v.
In this case if the job can be done with 1 pump, go 1 pump lol the 450 works well. Pump failures are somewhat rare but you'll hear alot of them on the net for 255/340 pumps. Not sure why. But if you have 1 pump and it fails, engine shuts down. If you have 2 pumps and 1 fails, engine melts down
This is why I try to run one pump. If I ever did dual pumps It would be a 450lph and a backup prob a 255 or similar so I could activate it and limp the car home. Nothing worse than being stranded and having to go through the tow process. dual pumps always scared me bc if that 2nd pump fails then its up to you to notice it or have fail safes implemented and hope they work.
Quote: Another thing is that my 450lph only pumped 284lph roughly at 12.2V which is much lower than advertised. This is due to low voltage but also probably other restrictions.
Low volts. Give it 13.5-14 off the alt
How did you measure the volume?
You can get a rough idea buy energizing the pump for a duration of time and measuring fuel flow into a quart container, but the appropriate way is with an actual test bench. This will include a timed circuit and a pair of solenoids to divert the test fluid into the measuring cup during the specified duration of time.
You can get a rough idea buy energizing the pump for a duration of time and measuring fuel flow into a quart container, but the appropriate way is with an actual test bench. This will include a timed circuit and a pair of solenoids to divert the test fluid into the measuring cup during the specified duration of time.
-- Joe
it was me who did the flow test. I energized the pump in the tank hooked up like it would be run on the car. No fuel rails tho etc. I had a 10amp charger on the battery which was just jumpered to the fuel pump wiring in my aftermarket fuse buss panel. Voltage from the battery dropped from 13.5ish volts to 12.2 with the pump on. Fuel was pumping into a 2.5 gallon container which was poured into gallon jugs. I set a timer for 60s and ran the pump for exactly 60s after priming it.
Side note is that the regulator was able to reduce fuel
pressure from 58 to 44psi with no issue or creep indicating it wasn't overpowering the stock fuel lines at the tank.
Here is is a picture of what the 4 micron fuel filter looked like after the test. My guess is that this afffected the flow
a smidge lol
This is why I try to run one pump. If I ever did dual pumps It would be a 450lph and a backup prob a 255 or similar so I could activate it and limp the car home. Nothing worse than being stranded and having to go through the tow process. dual pumps always scared me bc if that 2nd pump fails then its up to you to notice it or have fail safes implemented and hope they work.
Definately a concern...but it is somewhat rare since a good condition genuine walbro should go 1000-2000 hrs easily. 100,000 miles worth of driving lol
I always had good luck with those pumps.
I found in my car if it gets super lean it will act like a rev limiter. Fuel shut off basically and its enough to scare you to get out of the gas in a hurry. Generally the motor will be fine because its not detonating it just doesnt have fuel to accelerate. But theres always a chance it may not be fine lol just the way it is. At the high hp level you gotta keep an eye on stuff. I didnt do a good job on my last setup and it cost me a motor.
02-13-2017, 01:52 PM
