Fuel pump - now and later
Thread Starter
Staging Lane
Joined: May 2021
Posts: 97
Likes: 11
Fuel pump - now and later So I am in the process of building a single turbo LS (5.7 liter) car and am looking closely at fuel pump and injector sizing.
Leading particulars:
~600 BHP max goal @ about 12psi according to my calculations
E85 since it is readily available here
VSR Gen 2.5 7875.
1000cc injectors, probably spend the money for EV14s since I have used them before and it is amazing how well they idle.
I am looking at pumps like the Aeromotive A1000 which according to their chart will flow 600+ lb/hr at 60 psi.
Returnless system with the regulator loop at the back of the car, so no engine compartment fuel heating.
For the initial implementation I am going simple with a GM flash tune and a MBC. Later on I will be going with a stand-alone with tons of outputs.
12 gallon tank FWIW
I would like to keep a single pump setup, and it has to be inline, NOT in-tank
External high-flow mechanical FPR
So I understand the issues with running higher power pumps at full-time full power and the fuel heating issues from pump cooling. This is mostly a road race (track) car, with occasional street use (not a daily driver).
Question - Can I get away with running the pump full-time at 100%, at least until I get a stand-alone ECU that can implement a PWM scheme for the pump? Based on what I am reading here I believe I can if I am careful.
Thanks
Leading particulars:
~600 BHP max goal @ about 12psi according to my calculations
E85 since it is readily available here
VSR Gen 2.5 7875.
1000cc injectors, probably spend the money for EV14s since I have used them before and it is amazing how well they idle.
I am looking at pumps like the Aeromotive A1000 which according to their chart will flow 600+ lb/hr at 60 psi.
Returnless system with the regulator loop at the back of the car, so no engine compartment fuel heating.
For the initial implementation I am going simple with a GM flash tune and a MBC. Later on I will be going with a stand-alone with tons of outputs.
12 gallon tank FWIW
I would like to keep a single pump setup, and it has to be inline, NOT in-tank
External high-flow mechanical FPR
So I understand the issues with running higher power pumps at full-time full power and the fuel heating issues from pump cooling. This is mostly a road race (track) car, with occasional street use (not a daily driver).
Question - Can I get away with running the pump full-time at 100%, at least until I get a stand-alone ECU that can implement a PWM scheme for the pump? Based on what I am reading here I believe I can if I am careful.
Thanks
Last edited by Deude_Mann; Sep 14, 2024 at 12:35 PM.
A1000's are notorious for short life spans if they are run hot. I still use one on my gto, but I have one of their old 2 speed controllers on it and a 16 gallon fuel cell. If you run your tank low and have the pump at full speed all the time, I would not expect any of the old style inline pumps to be happy for long. How long any will last under those conditions is an impossible to predict crapshoot. As for newer stuff, I just have not kept up with what is out recently.
Thread Starter
Staging Lane
Joined: May 2021
Posts: 97
Likes: 11
A1000's are notorious for short life spans if they are run hot. I still use one on my gto, but I have one of their old 2 speed controllers on it and a 16 gallon fuel cell. If you run your tank low and have the pump at full speed all the time, I would not expect any of the old style inline pumps to be happy for long. How long any will last under those conditions is an impossible to predict crapshoot. As for newer stuff, I just have not kept up with what is out recently.
Last edited by Deude_Mann; Sep 15, 2024 at 12:23 PM.
Thread Starter
Staging Lane
Joined: May 2021
Posts: 97
Likes: 11
Those pumps are impressive. Huge flow rates, overkill for me.
https://www.magnafuel.com/efi-fuel-pumps.html
https://www.magnafuel.com/efi-fuel-pumps.html
Thread Starter
Staging Lane
Joined: May 2021
Posts: 97
Likes: 11
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I'd get the Magnafuel 4303, friends have had a good experience with those. Probably good for 750-800rwhp. You say 600 is enough but in my experience you'll want more.
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Staging Lane
Joined: May 2021
Posts: 97
Likes: 11
It still seems like extreme overkill to me. MagnaFuel rates the 4303 at 2000 hp @ 45psi (their documentation) which would be about 1400 hp @ 45 psi on E85 (30% reduction). An extreme overkill pump is going to be dumping more heat than necessary into the fuel so why use one? It is also a lot more expensive.
Last edited by Deude_Mann; Sep 15, 2024 at 09:19 PM.
My friend ran a 4303 to about 1150 crank hp on C16 and it was done, that rating you said about is not accurate. I know someone else who maxed it out at the at the same power level.
One of my cars made 550hp on motor, trust me, you'll want more.
One of my cars made 550hp on motor, trust me, you'll want more.
The 2000 hp rating for the Magnafuel 4303 is for naturally aspirated on gasoline at 45 psi. If you run the typical 58 psi base pressure and 12 psi of boost with a 1-1 boost referenced regulator you will be up to 70 psi. Higher pressure will lower the fuel volume the pump is capable of. Being boosted also requires more fuel with a richer AFR than NA. Then e85 requires a lot more fuel than running pump gas. They are also talking about crank hp not rwhp.
I've been running the Magnafuel 4303 for 7 years without issue street driving and racing. I've driven 2 hours each way without any fuel heating issues. I'm at 1000 rwhp and had to lower my ethanol content to 50% and add a 7 gph meth nozzle to make sure I had plenty of fuel. It's hard to get over 900 rwhp on a single magnafuel 4303, but below 800 rwhp they are an amazingly tough/reliable pump for a street car.
I highly recommend this pump for your power levels. Ignore the ratings magnafuel gives because they don't apply to your combo.
I've been running the Magnafuel 4303 for 7 years without issue street driving and racing. I've driven 2 hours each way without any fuel heating issues. I'm at 1000 rwhp and had to lower my ethanol content to 50% and add a 7 gph meth nozzle to make sure I had plenty of fuel. It's hard to get over 900 rwhp on a single magnafuel 4303, but below 800 rwhp they are an amazingly tough/reliable pump for a street car.
I highly recommend this pump for your power levels. Ignore the ratings magnafuel gives because they don't apply to your combo.
Regulator and return under the hood. Tank is 16 gallon and I have the return enter the tank at the bottom away from where the feed line exits the tank. I’m using the stock feed as a return. -12 from tank to pump, -10 pump to Y at rails, -8 to both rails from y, -8 out of rails to regulator, and -8 from regulator to stock feed which is now the return.
Last edited by BCNUL8R; Sep 16, 2024 at 03:16 PM.
You are going to get bored of 600flywheel HP real quick even in that little Miata. Plan to have your fuel system sized for more power. Overkill in that area is a good thing.
I agree. I originally sized my fuel system for 600 rwhp on stock bottom end ls1 and almost immediately wanted more. I had to redo the entire system a few years ago and now I'm going to have to add a second 4303 pump this winter.
Thread Starter
Staging Lane
Joined: May 2021
Posts: 97
Likes: 11
I have been there with the 'you will want more' with the last turbo Miata I had 
Keep in mind this is not a drag race car, nor will it ever be other than a casual run or two if that. A drag racing setup conflicts too much with a road race setup which is the primary purpose of this car. 550 WHP or so will be a lot, especially with the rear tire widths I am limited to in race compounds (285/35-15). It's already going to be a huge jump from the 320 WHP it is at now, and will only be useful at a few very fast tracks (like COTA).
Keep in mind this is not a drag race car, nor will it ever be other than a casual run or two if that. A drag racing setup conflicts too much with a road race setup which is the primary purpose of this car. 550 WHP or so will be a lot, especially with the rear tire widths I am limited to in race compounds (285/35-15). It's already going to be a huge jump from the 320 WHP it is at now, and will only be useful at a few very fast tracks (like COTA).
