boyracer Posted June 8, 2012 Share Posted June 8, 2012 I ordered John's Cars' fuel pump kit with the engine mounts for the LS1. It is an Airtex E8228 and came with no real info at all other than some generic installation instructions. Checked their website http://www.airtexproducts.com/product-catalog.aspx# and it shows this pump to have a flow rate of 38 GPH which translates into about 144 lph. Specs: "Rollervane; 12 volts; 100-125 PSI; 38 GHP; 5/16 hose; MPI Universal Replacement" This seems a lot lower than the Walbro 255lph that most people are using here with their LS1s. Is this enough fuel? Anyone else using this one?I plan to run a fairly mild LS1, maybe just a cam later on. Quote Link to comment Share on other sites More sharing options...
m1noel Posted June 9, 2012 Share Posted June 9, 2012 I used the pump from John's I received with the kit, but I don't believe it was the same one you have. Mine had no markings on it at all that I can find. It worked fine- good fuel pressure at all RPM's, but I found the Walbro to be somewhat quieter, especially on hot days. Quote Link to comment Share on other sites More sharing options...
boyracer Posted June 9, 2012 Author Share Posted June 9, 2012 I used the pump from John's I received with the kit, but I don't believe it was the same one you have. Mine had no markings on it at all that I can find. It worked fine- good fuel pressure at all RPM's, but I found the Walbro to be somewhat quieter, especially on hot days. The model number is so faintly etched onto the pump and it is the only indication of what model it is anywhere in the package. I don't know a lot about the mechanics of all this but the specs say 38GPh but pressure is 100-125PSI and other pumps like the Walbro note other PSI levels like 40 or 80PSI. So I don't know how these even compare regardless of the GPH numbers. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted June 9, 2012 Share Posted June 9, 2012 Try calling the guys at JCI and tell them about your concerns. They are really nice and helpful. You can also PM Phantom (or is it PhantomZ?) and ask him. His car was the prototype for JCI's kit. I'm not sure anybody will really be able to answer your question with absolute certainty. I think there are some guidelines about how much flow and pressure you need, but the pressure regulator can control (reduce) your pressure and much of your unused excess flow will go back to the fuel tank via a return line from either the pressure regulator or the fuel rail. Fuel flow needs are constantly changing, so again, I don't think anyone will be able to perfectly answer your question about flow requirements. My experiences: I installed an external Walbro and noise is not a problem at all (yes, I can hear it, but it is no louder than my production in-tank fuel pump on my S10). I used a Corvette FPR from Speedwaymotors.com and I installed a cheap fuel pressure gauge on the fuel rail. My fuel pressure is 50 psi at the rail at idle. I clogged a fuel filter right after my build and the fuel pressure gauge helped me immediately isolate the problem when my car stopped running, so I spent an hour cleaning the filter instead of a night of trouble shooting. One shortcoming of the pump you have is that it uses barbed fuel line fittings that screw onto plastic (many guys have done fine with barbed fittings with high pressure clamps). You will have to figure out some sort of adapter if you later decide to change to AN fittings on your lines. The Walbro is all-metal and it was pretty easy to use adapters to make it AN compatible. The mounting clamps for your fuel pump are nicer than the ones that come in the Walbro mounting kit (sold separately). If you have a 280z, you can probably use the stock hard lines to plumb your system, but if you have a 240z, you probably need to go to larger metal lines or just use 3/8 flex lines with AN6 fittings. Hope that helps at least a little. Quote Link to comment Share on other sites More sharing options...
Phantom Posted June 19, 2012 Share Posted June 19, 2012 (edited) I can't confirm that the pump JCI supplied you is the same one that was used on my car but I do know that I've never had a fuel flow problem. My LS1 is totally stock internally. It even has LS1 intake vs the LS6. It dyno'd at 311 rwhp on a single exhaust but is around 325 with the newer duals. At nearly 400 HP at the flywheel the LS1 is getting plenty of fuel. I'm pleased with the lack of noise from mine. I hear it bring the system up to pressure before actually starting the car but it is completely drowned out by the exhaust note - as it should be ! Oh - yes - I also used the stock fuel lines for the supply and return lines. That was part of the beauty of the installation on a 280Z - stock fuel tank, stock fuel lines, but with a new pump in the stock pump location. For further confirmation - when I was racing flat out at Texas Motor Speedway in Ft Worth my car got 10 MPG. At 120 MPH that would have worked out at 12 GPH. So if I was all the way down to 3.3 MPG a 38 GPH pump would have supplied the need. The only time I had an issue with fuel delivery was when my tank got below 1/4 full and I was accellerating out of a hard corner. That wasn't a pump problem, it was a baffling problem in the stock 280Z tank. Edited June 19, 2012 by Phantom Quote Link to comment Share on other sites More sharing options...
Leon Posted June 21, 2012 Share Posted June 21, 2012 Rated flow goes up with decreasing pressure. Ask for the pump curve. Quote Link to comment Share on other sites More sharing options...
Phantom Posted June 22, 2012 Share Posted June 22, 2012 Pump is designed to deliver the 38 GPH at the fuel injector design pressure. The pressure regulator maintains the pressure by bypassing excess fuel and returning it to the tank. Problems occur when fuel demand exceeds what the pump can deliver at the rated pressure. As long as the engine demand is lower than the 38GPH at the rated pressure everything will be fine. One thing that can be done is to size the pump off the rated flow of the injectors. That is what JCI has done - for LS1's using stock injectors. Quote Link to comment Share on other sites More sharing options...
boyracer Posted June 23, 2012 Author Share Posted June 23, 2012 Haven't heard back from JCI yet, but I contacted Airtex and this was their response when I asked about running an LS1 to about 400HP max: "Good evening. The E8228 does have 38 gph specs. A rule of thumb is 1 gph for every 10 hp. That would be about a 40 gph pump. This would be close. We also offer an E8248 that has 60-70 gph flow. I will get you a graph on Monday morning as I do not have it with me right now." So I guess a fairly stock LS1 with this 38GPH pump should be OK according to them. If I am maxing out the pump though, I would be worried about longevity. Will post the graph when I get it. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted June 23, 2012 Share Posted June 23, 2012 Buy it and run it. The worst that will happen is that your car will sputter - then you will know whether it is good or not. If it isnt up to it, it won't hurt anything. Quote Link to comment Share on other sites More sharing options...
Phantom Posted June 23, 2012 Share Posted June 23, 2012 FWIW - my completely stock internally '98 LS1 dyno'd at 311 rwhp on a single 2.5" exhaust. That would equate to about 390 HP at the flywheel. Since then I went to dual 2.5" exhausts and I have never had insufficient fuel from the pump. Quote Link to comment Share on other sites More sharing options...
boyracer Posted June 25, 2012 Author Share Posted June 25, 2012 Thanks for your input guys, I feel better about using this pump (though JCI still hasn't got back to me yet). Airtex sent me the graph: Quote Link to comment Share on other sites More sharing options...
Leon Posted June 25, 2012 Share Posted June 25, 2012 (edited) Rated flow goes up with decreasing pressure. Ask for the pump curve. Thanks for your input guys, I feel better about using this pump (though JCI still hasn't got back to me yet). Airtex sent me the graph: Hey, whaddaya know! Someone actually got a pump curve! As you can see, the fuel pump's rated delivery all depends on your regulated fuel pressure. If you know what fuel pressure your going to run, you will know how much flow your fuel pump is supposed to deliver. Edited June 26, 2012 by Leon Quote Link to comment Share on other sites More sharing options...
Phantom Posted June 26, 2012 Share Posted June 26, 2012 Now for the other half of the equation. Fuel injectors are normally rated using pounds (lbs.) per hour so the that rate will have to be divided by 6.073 to give gallons per hour. At that point you can get a true relationship between the pump delivery at the rated pressure for the injectors and what the injectors will actually require at their maximum rated flow.at that pressure. Quote Link to comment Share on other sites More sharing options...
boyracer Posted June 26, 2012 Author Share Posted June 26, 2012 (edited) Now for the other half of the equation. Fuel injectors are normally rated using pounds (lbs.) per hour so the that rate will have to be divided by 6.073 to give gallons per hour. At that point you can get a true relationship between the pump delivery at the rated pressure for the injectors and what the injectors will actually require at their maximum rated flow.at that pressure. Ok, so with the Corvette regulator running at 58 psi, and the stock injectors at say 28.8 lb/hr, I would need a minimum of 37.94 GPH? 28.8 / 6.073 * 8 cylinders = 37.94 So then if the pump is 38 GPH, it meets the minimum flow but if I increase the injector size, I would definitely need to upsize the pump as well, correct? Does it seem like JCI is cutting it really close? Edited June 26, 2012 by boyracer Quote Link to comment Share on other sites More sharing options...
Leon Posted June 26, 2012 Share Posted June 26, 2012 Looks like they got it spot on. If you plan to run bigger injectors, get a higher flowing pump. Quote Link to comment Share on other sites More sharing options...
Phantom Posted June 26, 2012 Share Posted June 26, 2012 Concurr with Leon. You'll be fine with the standard pump if you stay with the stock injectors. If you go bigger, you'll need a bigger pump. You're also planning on a larger TB, larger intake, an increase in flow capacity on you heads, at least 1 3/4"!headers, and a minimum of dual 2 1/2" exhausts - right? Either that or bolt on a supercharger or a turbocharger. You won't get the bang for your buck on the larger injectors of you don't improve the engines ability to breathe. Quote Link to comment Share on other sites More sharing options...
boyracer Posted June 27, 2012 Author Share Posted June 27, 2012 Concurr with Leon. You'll be fine with the standard pump if you stay with the stock injectors. If you go bigger, you'll need a bigger pump. You're also planning on a larger TB, larger intake, an increase in flow capacity on you heads, at least 1 3/4"!headers, and a minimum of dual 2 1/2" exhausts - right? Either that or bolt on a supercharger or a turbocharger. You won't get the bang for your buck on the larger injectors of you don't improve the engines ability to breathe. Awesome, thanks guys. Just wanted to make sure I was starting off on the right foot. No plans to upgrade injectors until I really need to BUT I am sure that day will come eventually... Quote Link to comment Share on other sites More sharing options...
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