Makes sense. I didn't catch the SSR = Solid State Relay when I first read it. I am pretty sure it was talked about earlier in the thread but it's been awhile since I spent serious time reading through it.

 

Aidan, why did you wire your relay ground to the OEM fuel pump ground instead of straight back to the battery? Convenience or concern about ground loops or something else?

 

probably convenience...I know I have 2 big wires running to the trunk.

let me go back and look at my pictures.

Edit: Yeah it was convenience. I think either one should work though.

You just need to provide a reference that the ECU ground gets "compared" against.

The transistor turns on when the voltage difference between the fuel pump signal and relay ground is smaller than a certain voltage.

ECU and battery ground should be very similar, if I were to do it again I might use the battery ground for the relay ground.

 

Cool, thank you for the help.

Off to grab a 1N4001 and some 8AWG wire. 8 gauge will give me some headroom to upgrade to a Walbro 450 later on if I need to. Planning to feed the DW300 ~13.5A at full boost, but a Walbro 450 would need ~19A at the same pressure.

 

8AWG. Damn, just gotta one up me.

I'm running that 450 you sold me on 10AWG wire. I think I did math at some point. And 10AWG was overkill for me.

http://www.calculator.net/voltage-dr...s=20&x=55&y=15

Cool calculator. ~4ft of wire. .20 voltage drop at 20Amps on 10AWG. .16 with 8AWG.

 

I used a different calculator and I think it was a little too conservative. 10 will be fine.

 

Are you running the stock fuel pump connector? Or something else.

At a possible 18-20 amps I wasn't going to risk the stock wiring. Not without a full fire system at least.

 

Stock connector. Punch the numbers into your calculator - the pessimist in me says they're 18awg wires, but it's only 6 inches of wire. At 20A, the voltage drop is actually lower than pulling the 20A down 4ft of 10awg.

 

I'm scared of fire not voltage.

I also severely over think things. Almost as bad as @EO2K but nobody gets on his level.

 

 

 

@EO2K uses shielded wiring for his fuel pump

 

lost it.

 

Gotta keep the pump noise out of the stereo, right?

 

The stock wires are 16awg, same as what's inside the tank.

Bulkhead Fuel Pump Harness Assemblies

I would do this, which is 10awg outside and 16awg inside, but....it's still 16awg inside. What's the difference between 16awg inside the tank, and 16awg inside the tank + 4" of it outside the tank?

 

I used a 4 pin bulkhead. 2 pins for power, 2 for ground. Stock bulkhead for level sender.

 

Link?

--Ian

 

You probably don't want it. Its the one from Racetronix that he and Leafy were endlessly complaining about.

The Radium one actually looks better, but its significantly more expensive.

 

I'm going to have a mod delete that link. It sucked. Overpriced garbage.

Leafy seems to think the GM specific model would work in ours but i disagree.

 

Looking closer at the Radium part, it's actually four 16awg wires inside the tank and two 10awg outside, so that's definitely an upgrade over stock. Having said that, I don't think it will fit under the stock fuel tank cover.