OK, WHO HERE HAS A STOCK ECU CAR RUNNING E-85???

I do. 440whp and 454TQ with an EvoGreen. If you plan on making ALOT more than that (let me know how) go with the bigger injectors. If not, downgrade to 880's.

I have plenty of IDC left over. . .

Your tuner should be able to tell you EXACTLY how big of injector you need. It is a simple mathematical calculation based on your fuel consumption (E-85), HP goal, and # of injectors. . .

 

And here comes the calculation: https://www.evolutionm.net/forums/sh...1&postcount=76

1200 or 1000 are fine on a stock like turbo. If they don't have 1000, go with 1200.

When it comes to fuel rail and lines, aren't stock ones pretty fat already? Don't people make huge (800-900) power on those on reg gas? That means they should be good for at least 600whp on E85. Or at least i would think so.

 

Not exactly the calculation I was thinking of . . . that seems like a pretty simplified way to guestimate it . . .

So what are your max IDC's with 1000's?

 

Guesstimate? Guesstimates usually do not involve calculation
What is wrong with it from your standpoint?

I was seeing over 100% because i'm on one Walbro pump, which doesn't seem to provide enough flow for my setup. I keep them around 100% though by reducing boost up top.

 

sorry 4 da off topic post: have you dynoed your e85+green setup yet? how bought some 1/4 track times? thanx

 

Nope.. My green is actually off right now waiting to be sent for rebuild (https://www.evolutionm.net/forums/sh...66&postcount=6)
I'll dyno it when i get it back and finally get a dual pump

Not a big fan of 1/4 mile though. Auto X or track is what i like.. I'm also still on the stock clutch at 45k miles, 1/4 mile won't be good for it

 

I don't believe your numbers take into account engine inefficiency. I could be wrong, but I think the flow #'s of the turbo are at the compressor outlet.

The equasion I've seen used most often is HPxBSFCxIDC=# of Gasoline/HR. #/hr x 10.2= cc/min.

0.65 is generally used for BSFC for forced induction motors on gasoline, and we want to shoot for an IDC of 80%, so for a 500 crank HP forced induction motor that works out to 500x0.65x0.8x10.2 = 2650cc/min. Divide that by 4 injectors and you come out right around 660cc injectors for that application. This is of course assuming that they are being fed sufficient fuel at a sufficient pressure.

So now lets assume we need to spray 30% more E-85, that 660cc injector need then grow to an 850-880cc need. (660x1.3=858cc).

A couple things to keep in mind - if you can't supply enough fuel at the proper pressures to the injectors, then your injectors will run out of steam prematurely . . . . and also that with the AEM EMS you generally need a bit bigger injector than with the stock ECU. . .

 

A 1000cc injector should be adequate for E85 with a stock framed turbo. For the technically inclined, injector capacities are typically listed at 80-90% IDC.

The factory fuel rail is not a limiting factor. . . at all. An aftermarket fuel rail makes it easier to mount a fuel pressure gauge. Otherwise, it is not needed, and wil not make an iota of difference, even with a large turbo.

Going up in altitude lessens the fuel demand, not increases it. Higher altitude = less power. Less power = less fuel requirement.

Aside from injectors, the limiting factor for E85 cars will be a single 255 lph pump, which will begin to lose its ability somewhere in the low to mid 400whp range. For a stock sized turbo at high altitude, this may not present an issue. But be advised of this potential issue anyway.

FYI

 

Hit the nail on the head with what us Colorado guys are dealing with... The 8's are getting away with using the 880's and single walbro due to the turbo. However, the IX's are kicking at the edge with single pumps and 880's...

Cheers-
E

 

Well if we assume that our load is g/rev*95 then:

If you hit let's say 260 load at 7500 rpm your airflow is 260/95 * 7500 = 20,526. Divide grams by 454 to get pounds and you get 45.2 lb/min of air that actually goes through the MAF.

For E85 that means injectors supporting 42.2 / 7.5(afr) = 6.03 lb/min fuel which is 6.03x454 = 2737 grams. Divide that by e85 gravity of 0.78 to get cc's: 2737/0.78= 3508 cc divided by 4 injectors is 877cc injector.

I don't know if an injector rated 880 actually flows 880 or less though. But in any case this is at 100%IDC. And veryyyyyyy approximate. That's why pretty much everyone's maxing out 880's. Maybe not on the stock turbo (unless your name is lucas) but on the green for sure.

And maybe i'm completely wrong with calculations.
But i do know that with a green and one walbro pump i'm seeing over 100%IDC, with the stock turbo it was under 100%. And i'm sure it'll get under 100% with twin pumps as numbers suggest 1000 are enough.
But if you have a modded evo tuned for high boost with E85, getting 880's is shorting yourself for no good reason.

In your case, EVOlutionary, you may see under 100% IDC because your boost falls off with MBC and/or you may be tuned lean.