what size fuel system do I need. E85

[TurboTJ]

I am getting ready to order my fuel system and I have a few questions. I will be tuning with an AEM EMS.

1. The shop I have been going to says that with 1000CC injectors, I will not idle right because they will not shut fully or something. Is this true? How big of injectors will I need?

2. How big of fuel pump will I need? I thought a 255 high pressure would cut it but they are trying to convince me to go with dual 255s. What pump will handle this it?

3. I will be replacing the fuel injectors, FPR, and pump. Is there anything else that would be a bottle neck or wouldn't be compatible with E85?

Thanks for the help!

 

[jrohner]

My 98 GSX loves e85. I have 680cc injectors, SAFC2, Evo3 16G, 3" exhaust. I'm not sure what fuel pump it has because I've never pulled it out to check it but the filter, FPR, and lines are all stock. 20psi seems to be the max with those injectors on e85. One of the best things about e85 is that since it's so high of octane, you won't wreck your engine if your tune is a little leaner than you'd like it to be.

The stoich mixture for e85 is 9.765 instead of 14.7; instead of changing that setting in my LC1 wideband i just left it at the gas setting and tuned it to 12:1 (on premium i tune to 11:1), which for e85 should be about 8:1. It didn't seem to like it any richer than that but it was fine if it went leaner (12.5:1 which is about 8.3:1). Don't plan on saving money even though e85 is cheaper because you get worse gas mileage running it; you should about break even running it instead of premium.

On my SAFC2 the settings for low throttle were near zero, but the high throttle settings were leaned back a lot since they run really rich on WOT stock.

Usually people say e85 is good for about 4-5 percent more power than gas, but it should be good for a lot more than that over premium since the octane is about 105-108.

Good luck, I'm sure you'll love running e85 (except for having to stop at the gas station more often).

 

[aero_sallee]

No you DSMLink to tune with. SFAC's can only to injectors up to 650's.

And you can probably get away with 1000's but for the same price I'd go with 1200's just to run at a lower IDC.

If you run E85 exclusively then you could go ~30% bigger than 650s with an SAFC. Since you don't have to hide the airflow to lean it out as much. The problem comes when you go back to straight gasoline. The extra timing isn't as bad either since E85 is much more detonation resistant.

Cold starts when its below 40-50 degrees would suck without some way to add fuel during cranking and warmup.

 

[jrohner]

If you run E85 exclusively then you could go ~30% bigger than 650s with an SAFC. Since you don't have to hide the airflow to lean it out as much. The problem comes when you go back to straight gasoline. The extra timing isn't as bad either since E85 is much more detonation resistant.

Cold starts when its below 40-50 degrees would suck without some way to add fuel during cranking and warmup.

Exactly. You can run bigger injectors with an SAFC on E85 than gas.

When it's cool out, I pretty much have to let my car warm up for a couple minutes before I take off or it's too lean and makes it 'surge' and jerk really bad when I first take off.

 

[Ajax]

95talonracer yeah what turbo are you running? Bc I have a walbro pump and afpr with -6AN lines, 1660cc injectors. The shop where I am getting it tuned said I should put another walbro inline and upgrade my lines to at least to -8AN pref -10AN before I get it tuned.

 

[RvlutionMtrsprt]

So the rest of the fuel system can handle it? I figured that a 255 would cut it. At what WHP number do you outflow the fuel lines and rail?

Thanks for all the help!

Not sure why you guys are even arguing about the SAFC issue.... he's running AEM, end of story.

You will not outflow the stock lines/rail until well past 500whp. Your tuner should be able to make the necessary dead-time compensations to get you car to idle no matter what size injectors you use. If you want headroom for the future, you should get FIC 1600cc's. If you don't feel that you'll need that much, get their (FIC) 1150 custom injector. The spray pattern on that injector is amazing and you can get a flow matched set straight from FIC. My gut would tell me to use the 1600's though. If you get to the point where you're running 10's and the stock lines/rail become a restriction you can upgrade them. Until then, I would not worry about it. Put the money towards tuning or something else mandatory.