Olds ticket to 9s... LS swap adventure.

[64nailhead]

What sump did you end up with? Im looking at going to a MF 750 and it says to have a -12 to the pump feed which means the sump would need a 3/4" outlet on the sump. Most i have seen are 1/2".

I found a sump on eBay with #12 fittings. The seller was out of Mass. and made them himself.

I have to say that I’m running the stock Fuel
Line for a vent. Seems to be working so far, but I’m running staged pumps.
Hopefully
Both of you guys are pulsing those 4303’s.

 

[Burning]

I found a sump on eBay with #12 fittings. The seller was out of Mass. and made them himself.

I have to say that I’m running the stock Fuel
Line for a vent. Seems to be working so far, but I’m running staged pumps.
Hopefully
Both of you guys are pulsing those 4303’s.

Do you have a link to that? I cant seem to find one.

Im just basing my information off the 4303 instructions. Did your sump work well, seem like good quality? I was gonna run mine full time, but im not opposed to dropping a single walbro in and have the second pump come on with a hobbs or even an output thru Holley.

I am wondering what that fuel system plumbing looks like. Do any of you run a intank as a primary and then run a 4303 as a secondary and come on with boost?

 

[64nailhead]

Do you have a link to that? I cant seem to find one.

Im just basing my information off the 4303 instructions. Did your sump work well, seem like good quality? I was gonna run mine full time, but im not opposed to dropping a single walbro in and have the second pump come on with a hobbs or even an output thru Holley.

I am wondering what that fuel system plumbing looks like. Do any of you run a intank as a primary and then run a 4303 as a secondary and come on with boost?

Holley, Haltech, Megasquirt and many others allow you to run a pump via PulseWidthModulation (PWM). The Magnafuel stuff is designed to run like that.I would not run a 4303 at full capacity all the time unless it was drag only build.
My helper and dyno owner tried running both of my AEM380’s at idle and it created quite a mess because my return couldn’t handle the volume. You’d need a 1/2” return line to run the 4303 on all the time imo. If you have the return size for the volume, then you have to deal with the aeration in the tank.

And running a 4304 and another pump is fine, but keep in mind you’ll have enough pump to make 1500whp on E85.

 

[Burning]

Holley, Haltech, Megasquirt and many others allow you to run a pump via PulseWidthModulation (PWM). The Magnafuel stuff is designed to run like that.I would not run a 4303 at full capacity all the time unless it was drag only build.
My helper and dyno owner tried running both of my AEM380’s at idle and it created quite a mess because my return couldn’t handle the volume. You’d need a 1/2” return line to run the 4303 on all the time imo. If you have the return size for the volume, then you have to deal with the aeration in the tank.

And running a 4304 and another pump is fine, but keep in mind you’ll have enough pump to make 1500whp on E85.

Yes i am aware of the PWM function that holley can use. But i didnt think that the 4303 can be run on PWM.

Thanks for the links to the sumps, exactly what i need.

 

[Northernregal]

For applications exceeding 1000 hp the pump should be feed with a -12line. MagnaFuel recommends the in-let line be one size larger than the out-let(i.e. -10in and -8 out or -12 in and -10 out). Since im running E85 i will make sure that i have this thing plumbed to its full potential. Also make sure that you have a true 1/2" or -8AN vent. The stock venting is not enough for the amount these pumps suck lol.

The 4303 is going to be staged, I am on dual 340's now and venting hasn't been an issue. I think you are right about my sump, I should upgrade my sump outlets.

Holley, Haltech, Megasquirt and many others allow you to run a pump his PulseWidthModulation (PWM). The Magnafuel stuff is designed to run like that.I would not run a 4303 at full capacity all the time unless it was drag only build.
My helper and dyno owner tried running both of my AEM380’s at idle and it created quite a mess because my return couldn’t handle the volume. You’d need a 1/2” return line to run the 4303 on all the time imo. If you have the return size for the volume, then you have to deal with the aeration in the tank.

And running a 4304 and another pump is fine, but keep in mind you’ll have enough pump to make 1500whp on E85.

My regulator was pretty much wide open at idle to maintain 43psi, I have the Holley -8 in/out unit. Though my -6 return was not an issue, it might be with the 4303.

 

[Burning]

The 4303 is going to be staged, I am on dual 340's now and venting hasn't been an issue. I think you are right about my sump, I should upgrade my sump outlets.



My regulator was pretty much wide open at idle to maintain 43psi, I have the Holley -8 in/out unit. Though my -6 return was not an issue, it might be with the 4303.

My brain hurts when i try and think of fuel plumbing system to use in tank unit, and also the in-line. Im guessing a Y Block post 4303 to pick up the fuel from in tank and then a single line up all the way to the front? Utilizing a check valve inline before the 4303 reaches the Y Block.

 

[64nailhead]

My brain hurts when i try and think of fuel plumbing system to use in tank unit, and also the in-line. Im guessing a Y Block post 4303 to pick up the fuel from in tank and then a single line up all the way to the front? Utilizing a check valve inline before the 4303 reaches the Y Block.

I mean this in a good, non-sarcastic way, you’re overthinking it. I just checked the 1st page of your build thread and you’re using a Holley Dominator. You do not need an additional pump if you’re running the 4303. It’s very simple to pulse your 4303. Set it up to run anywhere from 30-60% duty cycle until you hit 5-8 psi of boost, then have it 100% DC. That way you can run a normalish sized return line. It’s really easy - trust me. The only additional hardware needed is a solid state relay to run the pump.

ps - I’ll start following your thread to see when you update and respond there.

 

[Burning]

I mean this in a good, non-sarcastic way, you’re overthinking it. I just checked the 1st page of your build thread and you’re using a Holley Dominator. You do not need an additional pump if you’re running the 4303. It’s very simple to pulse your 4303. Set it up to run anywhere from 30-60% duty cycle until you hit 5-8 psi of boost, then have it 100% DC. That way you can run a normalish sized return line. It’s really easy - trust me. The only additional hardware needed is a solid state relay to run the pump.

ps - I’ll start following your thread to see when you update and respond there.

I guess my only concern is that as far as i know the 4303 was not designed to be PWM unlike the aeromotive variable speed pumps. I tried looking and seeing if anyone has done it and havent come up with anything. I guess you could run a separate PWM controller? NorthernRegal im sorry im hijacking a little bit lol

 

[Northernregal]

I guess my only concern is that as far as i know the 4303 was not designed to be PWM unlike the aeromotive variable speed pumps. I tried looking and seeing if anyone has done it and havent come up with anything. I guess you could run a separate PWM controller? NorthernRegal im sorry im hijacking a little bit lol

The complete how to. No such thing as hijacking this thread if we are sharing good ideas and solutions.

Variable speed fuel pump via holley(or any stand alone ems) - LS1TECH - Camaro and Firebird Forum Discussion

Forced Induction - Variable speed fuel pump via holley(or any stand alone ems) - Just gonna share this because it blows my mind people dont do this, or they have a standalone and still buy a 400dollar PWM pump controller.. Or worse a voltage controller This was done with a single wire from the...

ls1tech.com

To answer your question about the second pump, its just a Y fitting and a -8 check valve on the 4303 side. Probably going to be on the frame rail.


Something like this.

 

[64nailhead]

I guess my only concern is that as far as i know the 4303 was not designed to be PWM unlike the aeromotive variable speed pumps. I tried looking and seeing if anyone has done it and havent come up with anything. I guess you could run a separate PWM controller? NorthernRegal im sorry im hijacking a little bit lol

If you contact MF, they’ll tell you it can be pulsed. Our partner we ran drag week with last year ran a 4303 pulsed for the entire week. I know two others locally, that are doing it as well. I have to admit though, there is nothing wrong with running both pumps, just the 4303 is an animal at full voltage. The biggest issue with them is the heat they generate due to excess pressure according to MF. Running them PWM slows the overheating down as well.

I am truly curious of how the fuel trims will be when the 4303 turns on in the dual setup. I know my return (#6) is not big enough, but my fuel pressure spikes having a second aem380 turn on at 6psi. It takes until 12-14psi to level out to 58+current boost - which is fine because I live at less than 18 psi for about 1-1.5 seconds.