Multi Fuel Pump PWM setup... | AEM
13 posts / 0 new
Last post
evo8_pr
Offline
Last seen: 1 year 3 months ago
Joined: 08/28/2014 - 18:59
Multi Fuel Pump PWM setup...

I'm setting up a twin fuel pump anti surge tank with dual Walbro 450's which is going to be supplied fuel by a AEM E85 In Tank pump. I will be using Hella Solid State relays for the PWM functions and two standard relays interrupting thier voltage supply while not powered on. The setup goes as follows, HS0 will provide 12v to power on the standard relays, which will then provide the solid state relays with power. The SSR's will then be duty cycled with LS0 and LS3. Duty cycle will be incrementing with boost. HS0 is setup up as fuel pump and LS0 and LS3 are setup as General Outputs. Could someone confirm the setup seems correct?

 

evo8_pr
Offline
Last seen: 1 year 3 months ago
Joined: 08/28/2014 - 18:59
Just started the car up today

Just started the car up today, everything is working as planned. I plumbed a AEM 15psi sensor to my Surge Tank to be able to monitor it's pressure. With 50% duty cycle to the AEM intank pump the surge tank maintains 1.1 - 1.3 psi, for testing purposes I raised the duty cycle to 100% and the surge tank pressure increased to 2.8 - 3.0 psi. The main purpose of the pressure sensor is to monitor that surge tank stays minimally pressurized while using a low pump duty cycle in order to avoid unnecessary heating of the fuel.

AEM_NS
Offline
Last seen: 12 hours 19 min ago
Joined: 06/06/2014 - 09:31
Cool. Mind sharing a diagram

Cool. Mind sharing a diagram of how you wired this up and maybe some part numbers of the components you used?

evo8_pr
Offline
Last seen: 1 year 3 months ago
Joined: 08/28/2014 - 18:59
AEM_NS it took me a while to

AEM_NS it took me a while to put this together but for the benefit of the community, here it is. Just be aware that the setup is just as pictured above but the two(2) standard relay shown were just for photo purposes. They are replaced with Hella Mini ISO Relay -  p/n 933332151 http://hellahd.com/index.php/default/electrics/relays/mini-iso-relays/12v-spst/933332151-933332157/. This relay was chosen due to it having dual 87 outputs vs the more commonly found relays which switch between 87 and 87A. The Solid State Relays are Hella Mini ISO Relay - p/n H41773001 http://hellahd.com/index.php/default/electrics/relays/mini-iso-relays/12v-spst/h41773001-931773987/.

 

The above diagram will help you understand the wiring setup. Relays labeled "A" are the relays that control the Fuel Surge Tank pumps. The relays labeled "B" control the In-Tank pump which has the role of "fill pump" to the surge tank. I will go step by step on the wiring and setup of the "A" relays, the "B" would be the same with the difference that it only outputs one(1) pump.

To avoid confusion this is all for the relays labeled "A"

The Mini ISO Relay is wired as follows:

  • PIN 30 - (BATTERY +12v) Connect to battery with a fuse specific to your setup. This will transfer power to pins 87 upon activation which will drive your fuel pump(s)
  • PIN 85 - (GND) Connect to a GOOD ground source wire size should be equivalent to the one used for PIN 30
  • PIN 86 - (ACTIVATION) This will be the power signal to turn on the fuel pump(s), in my setup I wired this to HS0 in my Infinity and set this output as Fuel Pump in the software. Since this wire is just to activate the relay, the current draw is minimal and stays well below the 2.6A max of the AEM output
  • PIN 87 - (To Solid State Relay PIN 30) This will transfer power from PIN 30 to the Hella Solid State Relay which will then PWM that signal to the fuel pump(s)

The Hella Solid State Relay is wired as follows:

  • PIN 30 - (BATTERY +12v) This pin will receive power from the Mini ISO Relay PIN 87. This setup is done because if power is not interrupted while vehicle if "OFF" this relay will continue to transfer power to the fuel pump
  • PIN 85 - (NOT CONNECTED) Despite what you may read in other forums regarding this pin, this pin is not used/not connected
  • PIN 86 - (PWM) This will be connected to the Low Side Output of your choice depending on you setup. In my case I am using LS3, remember that all LS outputs have the PWM function. This is what regulates the Duty Cycle of the fuel pump, lowering its output
  • PIN 87 - (Fuel Pump +12v) This is the output that will power the fuel pump. This output varies with the Duty Cycle % received by the AEM Infinity LS output

 

In my setup the "Normal Relay A" having dual 87 outputs provides power to both SSR's on the "A" side and its corresponding fuel pump. I will eventually measure voltage at the pumps at different duty cycles and post results for the benefit of others who will eventually commit to similar setups

Any questions feel free to post below.

 

 

 

AEM_NS
Offline
Last seen: 12 hours 19 min ago
Joined: 06/06/2014 - 09:31
Thanks for all the info. I'm

Thanks for all the info. I'm sure it'll be helpful to others who want to use a similar setup.

evo8_pr
Offline
Last seen: 1 year 3 months ago
Joined: 08/28/2014 - 18:59
That's what the racing

That's what the racing community and forums such as these are for. Glad to be able to contribute... Some don't share info due to fear of others copying their "hard work". My view is if others catch up to me, then it's time to progress and do something better, that's the beauty of competition... Hope to contribute in everything I can, and hope others follow...

evo8_pr
Offline
Last seen: 1 year 3 months ago
Joined: 08/28/2014 - 18:59
Got some voltage readings

Got some voltage readings today at varying duty cycles.Frequency is set at 200hz. 

35%8.1v
40%8.3v
45%8.8v
50%9.0v
55%9.6v
60%10.0v
65%10.7v
70%11.0v
75%11.5v
80%11.9v
85%12.1v
90%12.5v
95%12.7v
100%13.3v

Not the most scientific test, but gives you more or less an idea of what to expect.

 

mackie
Offline
Last seen: 18 hours 42 min ago
Joined: 01/01/2015 - 10:11
Just a question, why do you

Just a question, why do you need a relay to supply power to the 2 relay? Is it not possible to just pwm the solid state relay directly instead of getting power from the mini iso solid state relay?

evo8_pr
Offline
Last seen: 1 year 3 months ago
Joined: 08/28/2014 - 18:59
I originally planned on doing

I originally planned on doing that, but unfortunately upon shutdown the relays would remain active. The relay states it is Normally Opened, and is like that on it's initial start up. But for some reason upon shutdown they remained in a closed state. If you were to unplug it, it would return to it's Normally/Opened state once again. Solved that issue by cutting power while vehicle is off with Mini ISO relay.

c3TurboVette
Offline
Last seen: 5 months 1 week ago
Joined: 11/09/2017 - 08:12
Couple of questions. 

Couple of questions. 

What fuel pressure regulator are you using that can deal with the flow of 2 450s?  When you run the pumps at full, is the regulator able to maintain low enough pressure?

What do you think about considerig the RPM as well as the boost to control the fuel pumps.  Does 3000 rpm at boost need half the fuel as 6000 rpm at the same boost?

makaveli200369
Offline
Last seen: 1 year 3 months ago
Joined: 11/12/2018 - 12:32
evo8_pr wrote:

evo8_pr wrote:

 

I have a question about this. Why in the outputs is RPM referred to as 0.1, 0.2, 0.3 etc? Instead of 1000 2000 3000? For the rows of 0 and 0.1 the duty cycle is 0 in all the cells. How does the engine start or idle? Thank you for educating me on this.

evo8_pr
Offline
Last seen: 1 year 3 months ago
Joined: 08/28/2014 - 18:59
This is the way I have it

This is the way I have it setup as we speak

 

 

makaveli200369
Offline
Last seen: 1 year 3 months ago
Joined: 11/12/2018 - 12:32
That is for your mini relay

That is for your mini relay though right? How about the LS0 output. I don't understand the units with the RPM being 0.1, 0.2, 0.3 can you explain how the X,Y tables units work? Thanks