I'm posting this because I keep seeing so many questions about running E85. "Will _____ size injectors allow me to run ______ turbo on E85?" Here is a guide that will answer all of your questions.
This guide takes the following into account.
1. All injectors flow exactly what they say they will. IE: 720cc injectors flow exactly 720cc.
2. All injectors flow exactly the same. IE: All injectors are perfectly matched (which is impossible in the real world)
3. Specific gravity of E85 is 0.79.
4. All calculations use a gasoline AFR of 12:1 - this equates to 8.05:1 in E85 #'s. Meaning - your wideband will read 12:1, but your actual AFR will be 8.05:1. Your wideband doesn't care what type of fuel you use, and will display numbers based on gasoline stohic (14.7:1).
With that in mind, on to the numbers.
390cc @ 100% IDC will support 21.80 lbs/min. Global Correction: +50.00%
390cc @ 80% IDC will support 17.44 lbs/min
450cc @ 100% IDC will support 25.15 lbs/min. Global Correction: +30.00%
450cc @ 80% IDC will support 20.12 lbs/min
550cc @ 100% IDC will support 30.74 lbs/min. Global Correction: +6.36%
550cc @ 80% IDC will support 24.59 lbs/min
580cc @ 100% IDC will support 32.42 lbs/min. Global Correction: +0.86%
580cc @ 80% IDC will support 25.94 lbs/min
650cc @ 100% IDC will support 36.33 lbs/min. Global Correction: -10.00%
650cc @ 80% IDC will support 29.07 lbs/min
660cc @ 100% IDC will support 36.89 lbs/min. Global Correction: -11.36%
660cc @ 80% IDC will support 29.51 lbs/min
680cc @ 100% IDC will support 38.01 lbs/min. Global Correction: -13.97%
680cc @ 80% IDC will support 30.41 lbs/min
720cc @ 100% IDC will support 40.24 lbs/min. Global Correction: -18.75%
720cc @ 80% IDC will support 32.20 lbs/min
750cc @ 100% IDC will support 41.92 lbs/min. Global Correction: -22.00%
750cc @ 80% IDC will support 33.54 lbs/min
780cc @ 100% IDC will support 43.60 lbs/min. Global Correction: -25.00%
780cc @ 80% IDC will support 34.88 lbs/min
850cc @ 100% IDC will support 47.51 lbs/min. Global Correction: -31.18%
850cc @ 80% IDC will support 38.01 lbs/min
880cc @ 100% IDC will support 49.19 lbs/min. Global Correction: -33.52%
880cc @ 80% IDC will support 39.35 lbs/min
950cc @ 100% IDC will support 53.10 lbs/min. Global Correction: -38..42%
950cc @ 80% IDC will support 42.48 lbs/min
1000cc @ 100% IDC will support 55.89 lbs/min. Global Correction: -41.50%
1000cc @ 80% IDC will support 44.72 lbs/min
1150cc @ 100% IDC will support 64.28 lbs/min. Global Correction: -49.13%
1150cc @ 80% IDC will support 51.42 lbs/min
1200cc @ 100% IDC will support 67.07 lbs/min. Global Correction: -51.25%
1200cc @ 80% IDC will support 53.66 lbs/min
1600cc @ 100% IDC will support 89.43 lbs/min. Global Correction: -63.44%
1600cc @ 80% IDC will support 71.55 lbs/min
1850cc @ 100% IDC will support 103.41 lbs/min. Global Correction: -68.38%
1850cc @ 80% IDC will support 82.72 lbs/min
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I assume the same equation could be applied to fuel pumps as well (hint..hint :) ) ? :dsm:
I thought about doing that, but I only have flow information for the Walbro 190, 255LP, 255HP & Supra pumps. I won't list information for the Walbro 190lph and Walbro 255LP because they are too small to safely run E85.
Ok, since DSM90AWD asked so nicely, here is the fuel pump information related to E85. As I said above, I only have the numbers for the Walbro series and Supra pumps. If anyone else has the numbers for different pumps, I can add those too. I just need flow rates at 15PSI & 30PSI (boost pressure, not total fuel pressure)...I can extrapolate (sp) the rest.
Notes:
1. All numbers assume you have your fuel pump rewired.
2. These numbers may not be correct. 15psi and 30psi numbers are based on the flow rates RRE supplied for the 2 pumps I will list, and I calculated the numbers in between. Though, I've seen different flow rates from different sites. I just figured RRE probably knew what they were doing when it came to DSMs.
3. Once again, all calculations based on 100% E85, with a 12.0:1 (gasoline) AFR, which correlates to 8.05:1 in E85 numbers. 4. I'm only listing the 255HP and Supra pump numbers because the other 2 Walbros are too small to run E85 with.
NOTE - The below numbers are the absolute max you can run these fuel pumps. If you run 0.01lb/min more, you run the risk of blowing your engine up. Do not take these numbers as gospel either. My calculations could be wrong, the flow rates I based these calculations on could be wrong. Please give yourself a decent margin of safety. I take no responsibility for anyone blowing themselves or their car up.
If e85 is 8:1 ratio and methanol is 5.5:1
would it be correct to say that if my system flowed 45 lbs/min of air that I would need 1687 cc injectors. 5.5/8= .6875 x 100%= 1.6875 x 1000cc = 1687cc. Or is it 8/5.5 = 1.45 x 1000cc = 1450cc
If e85 is 8:1 ratio and methanol is 5.5:1
would it be correct to say that if my system flowed 45 lbs/min of air that I would need 1687 cc injectors. 5.5/8= .6875 x 100%= 1.6875 x 1000cc = 1687cc. Or is it 8/5.5 = 1.45 x 1000cc = 1450cc
also what pressure is the scale based on.
If you are running 5.5:1 AFR on methanol, you will need minimim of 1200cc injectors. That's 100% IDC BTW. To maintain 80% IDC, then yes, you'll need 1450cc. All are based on SG of methanol being 0.7913
Oh, and the scale is based on absolute manifold pressure (IE boost), not total fuel pressure. If you wanted the total fuel pressure, then you'll need to add 43 to the psi numbers above. If you have a 1G, then obviously, you will have greater flow from the same pump due to having a lower base fuel pressure.
