Fuel pressure with E85

GNVYUS 1

Active Member
Dec 15, 2002
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Not unless you're going to cheap out and try to run an inadequate injector. If so and you're making decent power, you better have a huge pump that flows a ton of volume at your WOT pressure and not running it through the stock feedline.
 

Rafs-T-Type

Not so Senior Member
Mar 8, 2009
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Not unless you're going to cheap out and try to run an inadequate injector. If so and you're making decent power, you better have a huge pump that flows a ton of volume at your WOT pressure and not running it through the stock feedline.
well i really have no idea as to the correct answer, but if E-85 requires 30% more gas with the same amount of air (so the story goes)..wouldn't it make sense to have to raise the fuel pressure then to get to the correct ratio of air to fuel :confused:
 

novaderrik

Well-Known Member
May 12, 2004
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well i really have no idea as to the correct answer, but if E-85 requires 30% more gas with the same amount of air (so the story goes)..wouldn't it make sense to have to raise the fuel pressure then to get to the correct ratio of air to fuel :confused:
not if you run a bigger injector and have a fuel pump that can put out more volume for a given pressure.
 

GNVYUS 1

Active Member
Dec 15, 2002
3,425
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Stock injector is 28lbs, 28% larger is a 36lber, run them both to 70psi at WOT and which one will supply more fuel into the cylinder on the same fuel pump?

So, get the correct injector and matched fuel pump for your POWER and you're in business. Relieving any bottlenecks will help push those components like bigger lines ( -10an etc ), bigger rail ID etc.

Idling at 14:1 is fine, many like closer to 15:1 and even leaner while cruising but you're not hurting anything other than gas mileage at 14:1.

Tune for power at high 10's and get ready to make some madd torque.
 

Hot Air

E85 and S.E./Carolinas Moderator
Staff member
Nov 11, 2002
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Durham, North Carolina
The point is valid. E85 requires bigger injectors, bigger pump, and perhaps bigger fuel lines. If you have rubber fuel hoses, replace with teflon or other compatible material. A 50/50 mix of e85 and 93 attacked my 5 yr old Aeroquip rubber hose and stopped up my 40 micron SS filter and 120 injectors big time!
Conrad
 

Ttype6

Well-Known Member
Aug 17, 2004
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Flint,Michigan
If you have an engine that is in need of more fuel,and you are running a base pressure of 42 lbs. and have reached the end of your pump's ability to supply enough fuel,with your current injectors,to maintain the proper A/F ratio,it does you no good to buy bigger injectors. The thing you must first do is create the ability to move more fuel to the engine. The 3 ways to accomplish this is to send more voltage to the current pump or buy a bigger pump or a second pump. Once you do any of these things,you can raise the base pressure which will flow more fuel through the same injectors. Again,the first thing you must do is move more fuel.
 
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