curtis
Well-known member
They do have a little check valve at the outlet but most time than not they wear out or get fine scratches in them that cause them to leak down.
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Fuelab fuel pressure regulator I think I am over running it ?
- Thread starteronesickcrx
- Start date
onesickcrx
Well-known member
Quoting curtis:
Ok here's my thoughts on two pumps. In a perfect world two 255 would pump 510 at 43 psi all day long at 12 volts but they don't you could test every pump made and might not find two pumps that flow the exact pressure and volume all day long, I'm talking right down to 4 decimal places. Temperature of the fuel , temp of the day voltage etc all change there output. Now with that said if you have built a car that needs 500lph and one fails how do you know it failed and if it did.... does the backside of the pumps have a one way check valve to keep one from backfeeding the other. If one dies the other want feed all the fuel to the motor but part will flow back through the the other pump so your probably down to the stock pump volume. If you have two pumps and cut the rail between 2 and 3 and weld them solid and run two complete separate systems this will keep it from happening but if one fails and one doesn't your motor will lean out on two cylinders and die a quick death.
Do yourself a future favor and start watching ebay for an SX or a aeromotive big pump. Either one flows a crap load of fuel and will support a 1000hp and the volume and pressures are off the charts. I just sold an extra one on ebay a few weeks ago for $165 shipped. If you get one of those all you have to do is weld on a sump with a -10 fitting (cost is a fitting and a sheet of steel, maybe 20 bucks) I would say I'd do it but shipping on a fuel tank back and forth would be 60 bucks or more. I'm going to use an SX on mine after the surge tank and I have a 044 feeding the surge tank which is acting as nothing more than a circulating transfer pump
Now your thinking "but there's so many people selling those systems" Doesn't make it right and just because you can draw up a part and have a machine shop cnc cut a mounting fixture doesn't make the designer an engineer.
I agree every pump is not built the same, I was just ruffing out some numbers I got from a flowed 255hp. Also the pumps are less efficient when running them parallel they fight each other a bit. If my fuel pressure or my A/F change it would be something I would be looking into right away. I know its impossible to watch your gauges all the time but I do keep a good eye on them, and they are also all logged on my AEM so if I miss something I hope it will be getting logged before its too late. I plan to change my fuel pumps and my timing belt every 2 seasons by choice even if not needed just personal preference. Both of my 255's have check valves built in... once the car gets to driving around I will be taking down a bunch of notes, one will be how long of a duration it hold fuel pressure. This is a good way of keeping check on both check valves. I think running two separate systems is a bit much but I understand your thought on that. I really like weldon external fuel pumps but they are really loud so that kept me from buying one. I think the bosh 044 are also great pumps but one will not be enough for my needs so I would be stuck in the same boat if one craps out on me, plus they consume a huge amount of amperage compared to a 255. . Now I am in 100% agreement in putting a external pump and installing a sump for reliability and safety as far as fuel systems goes. I also think thats more of a race car mod and I refuse to make this a race car, this is my street car if it wasn't I would have already have installed a welded diff and a dog box trans and a weldon /ubbthreads/images/graemlins/devil.gif
A 255 takes 9.6 amps at 45 psi and 14.1 amps at 80 psi 195LPH x 2 ruffly 330LPH in tank since you don't get the full flow from both pumps
A 044 takes 15.5 amps at 45 psi and 19 amps at 80 psi 264 LPHx 2 ruffly 430 LPH doesn't fit in tank as a pair
Now since I would need to run two of either pump 255 is 28.2 amps and 044 is 38 amps at 80 psi. So this is the reason I went with the 255's if they fall short of my needs on E85 a Weldon will be the replacement.
I want to add that I am not a fan of Aeromotive fuel pumps I have seen a few start failing right in front of me in conditions it shouldn't fail. The SX is a nice unit but it takes 22.1 amps at 80 psi of fuel pressure but only delivers 240 LPH at that rate which is why I prefer a Weldon or a pair of 255's or 044's. Weldon takes 23.7 amps at 80psi and makes 697 LPH /ubbthreads/images/graemlins/worthy.gif
Curtis always keeping me on my toes I like it /ubbthreads/images/graemlins/grin.gif
Ok here's my thoughts on two pumps. In a perfect world two 255 would pump 510 at 43 psi all day long at 12 volts but they don't you could test every pump made and might not find two pumps that flow the exact pressure and volume all day long, I'm talking right down to 4 decimal places. Temperature of the fuel , temp of the day voltage etc all change there output. Now with that said if you have built a car that needs 500lph and one fails how do you know it failed and if it did.... does the backside of the pumps have a one way check valve to keep one from backfeeding the other. If one dies the other want feed all the fuel to the motor but part will flow back through the the other pump so your probably down to the stock pump volume. If you have two pumps and cut the rail between 2 and 3 and weld them solid and run two complete separate systems this will keep it from happening but if one fails and one doesn't your motor will lean out on two cylinders and die a quick death.
Do yourself a future favor and start watching ebay for an SX or a aeromotive big pump. Either one flows a crap load of fuel and will support a 1000hp and the volume and pressures are off the charts. I just sold an extra one on ebay a few weeks ago for $165 shipped. If you get one of those all you have to do is weld on a sump with a -10 fitting (cost is a fitting and a sheet of steel, maybe 20 bucks) I would say I'd do it but shipping on a fuel tank back and forth would be 60 bucks or more. I'm going to use an SX on mine after the surge tank and I have a 044 feeding the surge tank which is acting as nothing more than a circulating transfer pump
Now your thinking "but there's so many people selling those systems" Doesn't make it right and just because you can draw up a part and have a machine shop cnc cut a mounting fixture doesn't make the designer an engineer.
I agree every pump is not built the same, I was just ruffing out some numbers I got from a flowed 255hp. Also the pumps are less efficient when running them parallel they fight each other a bit. If my fuel pressure or my A/F change it would be something I would be looking into right away. I know its impossible to watch your gauges all the time but I do keep a good eye on them, and they are also all logged on my AEM so if I miss something I hope it will be getting logged before its too late. I plan to change my fuel pumps and my timing belt every 2 seasons by choice even if not needed just personal preference. Both of my 255's have check valves built in... once the car gets to driving around I will be taking down a bunch of notes, one will be how long of a duration it hold fuel pressure. This is a good way of keeping check on both check valves. I think running two separate systems is a bit much but I understand your thought on that. I really like weldon external fuel pumps but they are really loud so that kept me from buying one. I think the bosh 044 are also great pumps but one will not be enough for my needs so I would be stuck in the same boat if one craps out on me, plus they consume a huge amount of amperage compared to a 255. . Now I am in 100% agreement in putting a external pump and installing a sump for reliability and safety as far as fuel systems goes. I also think thats more of a race car mod and I refuse to make this a race car, this is my street car if it wasn't I would have already have installed a welded diff and a dog box trans and a weldon /ubbthreads/images/graemlins/devil.gif
A 255 takes 9.6 amps at 45 psi and 14.1 amps at 80 psi 195LPH x 2 ruffly 330LPH in tank since you don't get the full flow from both pumps
A 044 takes 15.5 amps at 45 psi and 19 amps at 80 psi 264 LPHx 2 ruffly 430 LPH doesn't fit in tank as a pair
Now since I would need to run two of either pump 255 is 28.2 amps and 044 is 38 amps at 80 psi. So this is the reason I went with the 255's if they fall short of my needs on E85 a Weldon will be the replacement.
I want to add that I am not a fan of Aeromotive fuel pumps I have seen a few start failing right in front of me in conditions it shouldn't fail. The SX is a nice unit but it takes 22.1 amps at 80 psi of fuel pressure but only delivers 240 LPH at that rate which is why I prefer a Weldon or a pair of 255's or 044's. Weldon takes 23.7 amps at 80psi and makes 697 LPH /ubbthreads/images/graemlins/worthy.gif
Curtis always keeping me on my toes I like it /ubbthreads/images/graemlins/grin.gif
curtis
Well-known member
The jury is still out on it but my buddy put an OBX under his honda I think it was like 250 shipped from ebay. Its been on since July and the only problem was an o-ring at first start up that was pinched on the attachment screws. Besides that if he's just a hair low on gas or if the car is on a slight hill and fuel slides forward away from the sump it starts screaming like hell. But so far has had zero problems. /ubbthreads/images/graemlins/dunno.gif Just haven't heard of any others running them.
I've actually thought about using a belt drive on mine and mount it on the engine where the ac compressor should live but never researched all the flow rates and such. They even make them with built in power steering all in one unit. Which would be super sweet because the alternator and pump could be mounted back there and the front of the engine would be cleaned off for monster sized turbo and insanity. /ubbthreads/images/graemlins/grin.gif
I've actually thought about using a belt drive on mine and mount it on the engine where the ac compressor should live but never researched all the flow rates and such. They even make them with built in power steering all in one unit. Which would be super sweet because the alternator and pump could be mounted back there and the front of the engine would be cleaned off for monster sized turbo and insanity. /ubbthreads/images/graemlins/grin.gif
Last edited:
onesickcrx
Well-known member
I am doing a all motor b series motor for my buddy and I keep thinking of trying OBX ITB's on it... I haven't made my mind up yet hehe. OBX use to be junk but I have heard they have improved some of there parts since I was into Hondas /ubbthreads/images/graemlins/dunno.gif
I toke some pictures of a few race cars at the shootout over the years with these pumps. I just think it must be a pain to keep primed for street car even with a check valve but it looks so bad ass and you will not run out of fuel with one on a mitsu /ubbthreads/images/graemlins/grin.gif
Magnus makes a beautiful bolt on setup.... /ubbthreads/images/graemlins/devil.gif
I toke some pictures of a few race cars at the shootout over the years with these pumps. I just think it must be a pain to keep primed for street car even with a check valve but it looks so bad ass and you will not run out of fuel with one on a mitsu /ubbthreads/images/graemlins/grin.gif
Magnus makes a beautiful bolt on setup.... /ubbthreads/images/graemlins/devil.gif
onesickcrx
Well-known member
Got the car running last night with 37 psi so new regulators working will right some new details and pics soon /ubbthreads/images/graemlins/grin.gif
onesickcrx
Well-known member
I didn't take the time to measure it which is uncommon for me, but you can clearly see its a whole lot bigger.
The proof is there I was out flowing the regulator, I put this new one on nothing else changed it worked perfect set to 37psi. I found a test done on setup similar to mine with smaller fuel lines made 470lph at 13v mines 14v so that's probably the difference /ubbthreads/images/graemlins/crazy.gif
The proof is there I was out flowing the regulator, I put this new one on nothing else changed it worked perfect set to 37psi. I found a test done on setup similar to mine with smaller fuel lines made 470lph at 13v mines 14v so that's probably the difference /ubbthreads/images/graemlins/crazy.gif
1qkfwd
Well-known member
I was gonna say the regulator is over run. I'm on twin wallys, each has a -6 goin to a y. The y goes to -8 to the rail. Magnus -10 rail to a aeromotive regulator to the stock return line. I've had pressure in the low 30s. FYI the aeromotive will never support enough fuel on our cars to make 1000hp. All there flow is at a low pressure. To make that kind of power we need at least 30lbs of boost. That sets fuel at 73 lbs. So our only real option is twin pumps, like the 255hp or and expensive high flowing pump like some of the stuff Weldon sells or an aeromotive eliminator. Any reason why your running -10 feed lines??
onesickcrx
Well-known member
Well I had two choice -8an or -10an knowing myself I am sure in the future ill get bored with my current setup, so it was smarter to run it once rather then twice. Just takes a sec to build fuel pressure in the line so I just turned the prime time up 2 sec /ubbthreads/images/graemlins/wink.gif
