School me on E85

Teej281

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Hey all,
Been keeping up with the member's install of the 10:1 Aluminator longblock and some other builds as well that are going E85 and was kicking around the idea of prepping my car for being an alcoholic...so to speak. lol I know the typical facts like you need a lot more E85 to get the proper A/F mix and that you are to remove as much aluminum from the fuel system as possible as the E85 corrodes the aluminum after time.

But I would like to know what pumps should be used, what all would the fuel system entail, and a lot more of the specifics of how much more fuel is needed to achieve the proper mixture and how much bigger injectors would you need than a typical pump gas build.

My goal is to do the fuel system ONCE and be done with it. Next summer I'm aiming for a KB 2.6 blower for my 2v and want to have the fuel system worked out before that. I was thinking FORE triple pump fuel hat for the Walbro GSS pumps and doing it return style so I have plenty of room for power. Overall goal is to push my little 2v to 700rwhp. The block is going to be built hopefully next winter and then heads and cams will follow that and Im hoping to make my rotating assembly higher compression(maybe up to 10:1 for better throttle response and such for toying around).

I'd ask this over on some of the other forums but you guys all really seem to know your stuff a lot more than others so I figured I'd ask you guys first. And I did a search and didnt find much at all really. Any help is appreciated guys!

Teej :beer:
 

SVT03Chris

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If you want to do it right the first time and have big plans for your motor go with a full return style fuel set up.
 

Teej281

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The triple walbro hat from Fore is setup for a return style fuel system. And come to think of it I never really researched what all is required for a return style fuel system. Im a tard when it comes to fuel systems. Suspension I can talk all day on(not super technical...but I know a thing or two on how to make stuff handle and/or hook).
 

stangaholic280

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Nothing. I just ordered the little brother of this kit with the double pumps. I am going for 750 and 2 of the walbro pumps should get me (and you) to that goal. This kit will come with everything you need excluding the 80lb injectors. Don't go any smaller on injectors. I would say you could save yourself some money though and get the 850HP kit instead. Saves you $500 and you will be clear to hit 700-750 easy.

I too am doing an E85 build so I can give you a little foresight into it. I would definitely recommend a return style also. People say it is more "primitive" but it is also a lot easier to work on/upgrade. No worries about having to deal with pesky upgraded FPDMs, BAPs, etc. Just big pumps, big lines, and big power!

As you probably already know E85 burns at about 30% more volume than gas. So at any given power level you will have to have 30% more pumping power than if you were running gasoline. However, the benefits are awesome. It burns cooler. It burns cleaner. It's octane is 100-105 so you can run a much more aggressive tune without it being aggressive! I think you are definitely making a wise decision.

Here is my thread if you'd like to follow it. Haven't gotten to the fuel system yet, but I will soon. :beer:

http://www.svtperformance.com/forums/terminator-talk-229/716398-stangaholics-2-8-kenne-bell-more-build-thread-lots-pics.html
 

GodStang

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It's octane is 100-105 so you can run a much more aggressive tune without it being aggressive! I think you are definitely making a wise decision.


E85 octane is like 94 not 105. The reason you can tune it more aggressive is that it burns cooler.
 

GodStang

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http://www.iowarfa.org/PDF/E85_values_fund/E85 Fact Sheet.pdf

Think again...and stangaholic, I'm following your thread like a hawk!!!

That is very very misleading....

While it's RON, Research Octane Number is 104 its MON, Motor Octane Number is only like 95 or 96 in that area.

Just thought you guys might be interested in this Exx test data from a recent SAE publication.

Note how the pump octane number [(MON+RON)/2] flattens out to about 96.

View attachment 74424

This is a little lower than other test data of PON ~ 99, (albeit w/ different test methods), I previously posted as shown here:

attachment.php


Heywood gives neat (100%) ethanol as having an MON = 89, and RON = 107, so PON = 98. That is why the curves above flatten out at higher percentages of ethanol.

In any case, it's not the 104 (or higher) you may keep reading on the internet all over the place. (Knock reduction comes primarily from charge cooling, as opposed to what one may refer to as the "chemical" octane.)
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If one goes through the math, they’ll find that the theoretical change (reduction) in air temperature from this evaporation process is given by

ΔT = (Lv/cp)·(1/AFR)

Where Lv is the latent heat of vaporization, and cp is the constant-pressure specific heat of air, (~ 1 kJ/kg·°C). The specific heat of the material basically describes the amount of energy required (per unit mass) to change its temperature by a given amount.

For typical gasoline, Lv is ~340-350 kJ/kg, versus 840 kJ/kg for neat ethanol! So as you can see, it’s a big difference. The fact that you have to run more fuel with ethanol also adds to the cooling effect via the AFR. As I’m sure you know, for typical non-oxygenated gasoline, the stoichiometric air-to-fuel ratio is AFRs ~14.6. For neat ethanol, AFRs = 9. Methanol offers even more charge cooling benefit, whereby Lv = 1103 kJ/kg and AFRs = 6.47.

Although indeed the "chemical" octane of E70 and E85 may be very close, the cooling effect of E85 will be greater than that E70 since it contains more ethanol, and as such, has a lower stoich AFR. (For more details, see reference here => Stoichiometry of blended fuels) For E85, Lv = ~770 kJ/kg and AFRs = 9.8. For E70, Lv = 700 kJ/kg, and AFRs = 10.6. Therefore, since it cools better, what one might refer to as the "effective" octane, is higher for E85 than it is for E70.

Also, since E70 and E85 have different stoichiometric ratios, that alone is a reason to have separate tunes for each, so that the proper AFR is maintained in open loop.
--------------------------------------------------------------------
The equation I gave, actually does include the mass of air and fuel. If you work it out, you'll find that you just end up with the ratio in the final expression, which is where the AFR comes in. I'm sure if you stare at it a bit, you'll recognize that in short order. It's very trivial.

Therefore, you can compare the ΔT's of gasoline and E85 using that equation and the Lv and stoich AFR data I gave. (Just divide the stoich ratio by the equivalence ratio you typically run to get the actual AFR.)

Cars that use port injection actually will see some drop in manifold temp since the fuel backs up behind the valve and sits there for awhile and starts to vaporize before it actually goes into the cylinder. (It actually can sit there quite awhile, around injector duty cycles of near 100%). At light loads, it might not be noticed. With DI, yes, the drop would all occur within the cylinder as you suggest. Perhaps that is the case you were thinking of.

The Killer Chiller is a great product. Nonetheless, I don't know that one would benefit much from it here, either. As you know, there is that minimum enthalpy requirement that must be met, so one can actually get too cold. Then the fuel wouldn't all be vaporized. (Basically the reason behind having a choke - add extra fuel when the engine is cold, because all the fuel can't evaporate. This is also the reason why they switch to E70 in the winter up north. Otherwise there is a cold start problem.)

With an NA vehicle, use of E85 could definitely cause the effect you mention - as the cools in the port, it would result in more air getting pulled in resulting in a higher air density in the intake. Same would be true with a turbo application...as temp goes down, pressure would tend to drop, so the turbo would force more air in to get to the set boost pressure. With a positive-displacement blower, cooling the air after it's been compressed won't do anything since that type of compressor is a fixed-volume machine, by definition....a fixed volume, and hence mass, of air goes in per revolution of the rotor. Cool it down and the pressure drops with the drop in temp. But the anti-knock benefit would still be there, or course.
 

Teej281

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Well I stand corrected. Most of that is gibberish to me but I got some useful info out of what I did understand. Lol i still really wanna do the swap. Now one question I have is if I went full tilt minus the injectors for my initial kb install and run that fuel system, would I have any issues? And what's with the idea that if you run too big of an injector that you'll have drivability issues? You don't always run around in boost. So running around when your just driving in traffic you should have drivability issues since the injectors are too big for not being in boost. Thoughts on that?
 

1wild-horse

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and having said that i might just look into methy injection. It seems like the benefit is the cooler charge temp which is the end result with meth injection; only for waaay less $$. wonder if they'd let me put "meth addict" on my license plate? LOL
 

Teej281

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Probably not. Lol but it's not only the cooler temps but the price compared to race or even pump gas that is the advantages. I think I'm going E85. Let's burn some corn people!!!
 

GodStang

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Well I stand corrected. Most of that is gibberish to me but I got some useful info out of what I did understand. Lol i still really wanna do the swap. Now one question I have is if I went full tilt minus the injectors for my initial kb install and run that fuel system, would I have any issues? And what's with the idea that if you run too big of an injector that you'll have drivability issues? You don't always run around in boost. So running around when your just driving in traffic you should have drivability issues since the injectors are too big for not being in boost. Thoughts on that?

Your injectors are not always spraying full out. If you run FRPP 80lb ($380 from Tousley) injectors on a return style you will be good till 850-900rwhp and also be fine at lower power levels. Also doing a return system will help you have a cleaner tune.

As far as will you have issues if you do not install the injectors what size do you have now? You really need a decent size injector if you are twin screw and E85. I have seen a few make into the 600s return and E85 with 60s but man you really need 80s.

and having said that i might just look into methy injection. It seems like the benefit is the cooler charge temp which is the end result with meth injection; only for waaay less $$. wonder if they'd let me put "meth addict" on my license plate? LOL

From what I have seen in the past 5 years with Meth injection and 03-04 Cobras with twin screw (have to say this because someone will come on with their buddies neon made 10000000rwhp with meth on a turbo, this is not a turbo) you see very very very little gains. I have seen the average around 10 rwhp and Meth with some getting up to like 20rwhp. Also its extra pieces to fail and you have to keep adding it meth. Many people get sick of the continually adding fluid. E85 on Twin Screw 03-04 Cobras I have seen many many many with 75-100rwhp gains on near stock Cobras and some even more. Don't Really think Meth is a good replacement for E85. Just my 2 Cents.
 

Teej281

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Well right now I'm stockish so I'm sittin with my 21's but when I go E85 and twin screw I might as well go with the 80's and full fuel system so I only ever do that once and done. So with sub-450rwhp and E85 I'd be fine with 80lb injectors?
 

suaveflooder

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WOW! Godstang, you have a lot of good info. I have also been playing with the idea of going E85! Thank you for your information! :beer:
 

da2k17

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teej281 just curious, where are you going to get the e85? i have not seen it available anywhere in PA yet, i ask because i have been waiting to go that route as well.
 

Teej281

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There is a couple stations within a half hour of my house and my college has about 6 within 10 miles of it. For you though being in Scranton, you don't have any stations within 50 miles of you. :/ just looked it up.
 

nolyaw

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700 rwhp, no problem with returnless. E 85 is the shiznet.
 

Teej281

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I'm going return style I think. I dont wanna deal with upgrading everything needed for returnless. Plus I like what I'm seeing about getting a cleaner tune with the return style. Plus if the potential is there, I'd like to get more than 700rw with this setup. High compression, high boost, and high horsepower numbers is what I'm after with this setup.
 

GodStang

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I'm going return style I think. I dont wanna deal with upgrading everything needed for returnless. Plus I like what I'm seeing about getting a cleaner tune with the return style. Plus if the potential is there, I'd like to get more than 700rw with this setup. High compression, high boost, and high horsepower numbers is what I'm after with this setup.

I have run three different returnless systems and have spent tons and tons of money trying to stay true to the original Cobra design. My advice F@$K IT!! I have about 200 miles on my latest system and the car never runs. So go return style any time you can.

80s may be too big for 400rwhp but I will ask around.
 

nolyaw

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I know alot of people blow smoke up other peoples ass by saying " my monster runs like stock", but no shit my car does. Perfect starts, rediculously smooth even idle, no surging, bucking, or any goofiness of any sort. Ever.

SCT 3000, 80's, -8AN line, twin GT's, MDM Jr., and BAP. I am picky as hell, and very meticulous. I see no issues, ever.

Not saying which way to go, cause I could give a shit less, but with a good tuner and proper returnless setup, the results CAN be phenomenal. I don't really know the cost difference, nor do I care (whats an extra four or five hundred bucks when you are already $36k deep?), but I do understand that big (750 whp +) power is cleaner to obtain with less headaches with return style.

I am now a c-hair below 700 whp, and the car truly does operate like a stock automobile.
 

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