Limitations of fuel pump

**whitelightning** · 03-31-2010

Alright im trying to convert to e85 (really cheap around my area). So im wondering if i need to do a fuel pump rewire kit and voltage booster or what exactly i need? If anyone has done this or knows for sure your advice is appreciated

**JoshMcMadMac** · 03-31-2010

Originally Posted by whitelightning

Alright im trying to convert to e85 (really cheap around my area). So im wondering if i need to do a fuel pump rewire kit and voltage booster or what exactly i need? If anyone has done this or knows for sure your advice is appreciated

Fuel injectors will not hold up to it...not to mention tuning for it. The voltage booster is unrelated.

**whitelightning** · 04-01-2010

Originally Posted by JoshMcMadMac

Fuel injectors will not hold up to it...not to mention tuning for it. The voltage booster is unrelated.

yeah i figured that went without saying so i didnt type it out i already have a custom tune lined up and have the injectors. And im told by people who should know what they are talking about (zzp and others). that the fuel pump might not be able to do the job. and that the fuel pump looses voltage through the small wire it comes with from the factory by raising the voltage output this helps. that is how it is related. not trying to be a dick but dont comment on my thread if all you are trying to do is tell me how my info is wrong. i just wanted advice

**JoshMcMadMac** · 04-01-2010

Originally Posted by whitelightning

yeah i figured that went without saying so i didnt type it out i already have a custom tune lined up and have the injectors. And im told by people who should know what they are talking about (zzp and others). that the fuel pump might not be able to do the job. and that the fuel pump looses voltage through the small wire it comes with from the factory by raising the voltage output this helps. that is how it is related. not trying to be a dick but dont comment on my thread if all you are trying to do is tell me how my info is wrong. i just wanted advice

Damn, kid...f@ck you then, I guess. I never said you were wrong, I said the voltage booster was unrelated, which it is. The fuel pump rewire is a good idea, which can be done for a few dollars worth of wire. How are we supposed to know what you think about injectors? If you cannot search up all of this information that has already been hashed out here, one can only assume that you are not capable enough to already know these things.

Summary: I am a dick and your information is wrong. Not only that, but your have your wrong information all mixed up.

**FoSHO99** · 04-01-2010

Ever since I switched to E85, it's been $2.10-2.20 a gallon consistently in the midst of the $2-4 it costs for 91 octane with ethanol. E85 is rated at 104 octane and would probably reduce knock as high as 6-9* to 0. If you wanted to custom tune it for mpg, you could probably gain back that mpg to damn close of what it was. Or you could run 87 octane and tune it to get 30+mpg hwy. I just run it because to me its race gas on the cheap and we don't have anything good above 91 octane here.

What you will want to do, is based on your mods, (you haven't listed any yet) run 42 or 65# injectors with a fuel pump rewire. Add 30-40% to the IFR table and tune from there. Change the fuel filter after the first full tank and then again after 3-4 fills. Then make sure no one else drives the car or fills it with regular gas again.

**whitelightning** · 04-02-2010

Originally Posted by FoSHO99

Ever since I switched to E85, it's been $2.10-2.20 a gallon consistently in the midst of the $2-4 it costs for 91 octane with ethanol. E85 is rated at 104 octane and would probably reduce knock as high as 6-9* to 0. If you wanted to custom tune it for mpg, you could probably gain back that mpg to damn close of what it was. Or you could run 87 octane and tune it to get 30+mpg hwy. I just run it because to me its race gas on the cheap and we don't have anything good above 91 octane here.

What you will want to do, is based on your mods, (you haven't listed any yet) run 42 or 65# injectors with a fuel pump rewire. Add 30-40% to the IFR table and tune from there. Change the fuel filter after the first full tank and then again after 3-4 fills. Then make sure no one else drives the car or fills it with regular gas again.

Thanks alot for the help man!

**TheOtherNick** · 03-31-2010

You need a tuner.

**FoSHO99** · 03-31-2010

42 or 65 pound injectors based on your mods, then a fuel pump rewire wouldn't hurt. The stock pumps usually hit their limit at 400whp with a rewire and the right injectors.

**whitelightning** · 04-01-2010

Originally Posted by FoSHO99

42 or 65 pound injectors based on your mods, then a fuel pump rewire wouldn't hurt. The stock pumps usually hit their limit at 400whp with a rewire and the right injectors.

thanks alot

**Bio248** · 04-01-2010

get a rewire and see how it works out. most of the time you wont need it for a 42.5# injectors, but anything bigger and it helps. the fuel pump itself is good for a lot of fuel dumping potential and our aftermarket choices are very limited and come with some flaws.

i would install a fuel pressure gauge and watch your pressures up top. if they dont drop off then you are still good. either way the only thing youre avoiding is detonation from being lean. if its not knocking then who cares?

**buster** · 04-01-2010

I'd think twice. Everybody I know who has a Flexfuel vehicle and has run it purely on alcohol said the car would go roughly 3/4 as far on a tank of alcohol as gasoline. Do the math, I don't think it's worth the expense of the conversion, unless you are really interested in the whole tree hugger thing.

However if you do try it keep us tuned on how it works out.

**Bio248** · 04-01-2010

Originally Posted by buster

I'd think twice. Everybody I know who has a Flexfuel vehicle and has run it purely on alcohol said the car would go roughly 3/4 as far on a tank of alcohol as gasoline. Do the math, I don't think it's worth the expense of the conversion, unless you are really interested in the whole tree hugger thing.

However if you do try it keep us tuned on how it works out.

if you do this switch with 'hippie' in mind then youre dumb. this stuff is cheap race gas. if youre running it expecting good mileage then youre already looking in the wrong direction. the point of running e85 in a performance car is the high octane and the cooling effect the ethanol has. anyone who knows anything about fuels knows that switching to e85 alone will give a great gain in performance.

**whitelightning** · 04-02-2010

Originally Posted by Bio248

if you do this switch with 'hippie' in mind then youre dumb. this stuff is cheap race gas. if youre running it expecting good mileage then youre already looking in the wrong direction. the point of running e85 in a performance car is the high octane and the cooling effect the ethanol has. anyone who knows anything about fuels knows that switching to e85 alone will give a great gain in performance.

i agree and in case people are wondering no, im no hippie this is about performance

**whitelightning** · 04-02-2010

Originally Posted by buster

I'd think twice. Everybody I know who has a Flexfuel vehicle and has run it purely on alcohol said the car would go roughly 3/4 as far on a tank of alcohol as gasoline. Do the math, I don't think it's worth the expense of the conversion, unless you are really interested in the whole tree hugger thing.

However if you do try it keep us tuned on how it works out.

this depends on the price you have to remember that it is not the same price everywhere. it is a WHOLE DOLLAR cheaper here where i live. the math has been done and when e85 is 50 cents cheaper it is the same as gasoline in the end. thanks!