E85Forum.com

rickman454 · Joined: 11 Dec 2006 Posts: 3 Location: Iowa

I am really stupid when it comes to anything math-related. Embarassed

From what I gather, you need to go 30% richer on the fuel when going from gas to E85 naturally aspirated. The O2 Technology website also states that you must go from a 5.5:1 fuel/nitrous ratio to a 3.75:1 fuel/nitrous when moving to E85 on spray. This is also 30% richer.

The following chart lists the nitrous and fuel (gas) jets needed for my dual carb set-up:

N20/fuel
200 HP .052/.058
225 HP .059/.065
275 HP .065/.073
325 HP .073/.078
350+ HP .085/.082

How do I determine the appropriate fuel (E85) jet? I have gathered that I need to increase the “area” of the jet to achieve a 30% increase in fuel flow. I am assuming that I would keep the nitrous jet the same and just increase the fuel. Question

1) Can anyone explain the formula/calculations in layman’s terms? I was a poli-sci major. My math skills suck major booty!
2) How do we take into account the dual carbs? (i.e. two fuel jets and two nitrous jets)

hotrod · Joined: 19 Apr 2005 Posts: 872 Location: Colorado

sqrt ((gasoline fuel get dia ) ^2 x 1.3 ) = new get size.

Example 0.078 fuel jet for 325 hp

Square the original fuel jet size:
(.078 )^2 = 0.006084

Multiply that by 1.3 :

0.006084 x 1.3 = 0.0079092

Take the square root of that number:

sqrt (.0079092) = 0.0889 is your new jet size for 30% more flow.

Larry