E85 Fuel System

[Aero STI]

I started piecing together my new fuel system for my 818 and I thought I would share the parts in case someone is looking for inspiration.

Boyd Tank
Aeromotive 340 Stealth Pump
ID1000 Injectors
Long runner 2.5i IM
Outfront Motorsports Fuel Rails
Fuel Lab 535 Fuel Pressure Regulator
Fragola 0-100 PSI Liquid Filled Fuel Pressure Gauge
Parker Push-Lok 801 Hose
-8 AN feed from pump to Y then -6 AN to each rail.
-6 AN from each rail to FPR
-6 AN from FPR to Ethanol Content Analyzer
-6 AN from ECA to tank

Assuming the 340 fuel pump can handle 55-60 PSI base fuel pressure I should have no problem supporting my 500 WHP on E85 goal.

[JeromeS13]

For 500 WHP on an EJ25, you're going to need much larger than ID1000's.

[Aero STI]

For 500 WHP on an EJ25, you're going to need much larger than ID1000's.

This is a common misconception and causes people to run enormous injectors when it isn't necessary. The key is raising base fuel pressure and having a hard wired pump that can keep up. The EV14 injector is best suited for high pressure applications.

A quick search reveals...
http://forums.nasioc.com/forums/show...3&postcount=56

http://forums.nasioc.com/forums/show...1&postcount=23

I've purchased quite a few sets of ID1000s and have personal experience making 440 WHP on E85 with only 50 PSI base pressure and reasonable IDC. I was about to shoot for the ID1300s, but Junior is most likely tuning my car and he pushed me to these injectors for my peak power goal. He also has numerous examples of EJ25 Subarus running id1000s making 500 WHP on E85.

So thanks for your opinion, but I disagree.

[longislandwrx]

I like your setup,

I've been considering using a dead end fuel setup, using a radium surge tank and regulator. I'm really trying to keep everything clean.

[Aero STI]

I'm reasonably happy with everything so far, except for the aeromotive pump which failed after 500 total miles, 400 on E85, 250 on E85 at 55 PSI base fuel pressure. I'm running a Walbro 450 now.

The highest peak number I've seen is 490 WHP and 550 WTQ at this point. AFR at 12:1 and IDC is a bit too high, sitting around 95 to 100. I definitely will reach 500 whp with the ID1000s, but not much more.

[Hindsight]

That's crazy power for an 1800lb car! Are you tuning via an AccessPort or open source?

[longislandwrx]

would you be better off with a set of 1100s from FIC? benefits of a smaller injector and still have a lower idc?

[Aero STI]

That's crazy power for an 1800lb car! Are you tuning via an AccessPort or open source?

I started with open source MAF based, but switched to the Cobb AP for ease of tuning speed density.

would you be better off with a set of 1100s from FIC? benefits of a smaller injector and still have a lower idc?

I don't know much about fuel injector clinic products. Most reputable Subaru tuners suggest Injector Dynamics. Better would be ID1300 as Jerome suggested. The new walbro 450 has reduced IDC to 90% or less. That's while running 26 PSI tapering to 24 at redline and 12:1 gasoline AFR (still E85).

[apexanimal]

where do you ideally want the afr to be if 12:1 is too lean for e85?

[Aero STI]

I'm not too lean with 12:1 AFR. The consensus is high 11 to low 12 AFR on the gas scale is fine for E85. The IDC in the 90's is all that is concerning, but as I understand it the Subaru ECU is a bit off and will let you go to 105-107% IDC.

[C.Plavan]

You are going to have to stop for E85 ALOT with that size tank.

[craigfree]

Did you do anything to protect the aluminum Boyd tank from e85? I found mixed opinions on how aluminum handles e85. I wound up having my tank alodined, but I'm still uncertain how it's going to hold up. Did you do anything to protect the aluminum?