e85 pros and cons

[mwiener2]

ok, run a stock tune

[wichitalegacy]

I plan on going e85 by next summer . I have to map out gas stations to get me back from the tuner . I could easily max out my 816cc injectors with my gt30r setup, so I am guessing 1500cc injectors for e85 .

[Revolutions Performance]

Ok- Lots of misinformation in this thread. Let's see what I can clear up for you guys. I do 5-10 e85 tunes/month.

 

You do NOT need dual fuel pumps. A single walbro pump provides enough fuel for 650+ whp on pump gas. On e-85 a single walbro is good to about 450whp. You WILL need larger injectors. I reccomend modifying the stockers to 840cc's. These will be good to about 400whp on e85. You will need special tuning to take advantage of e-85.

 

Now for the benefits-

 

E-85 runs much cooler than gas. That means you will see lower coolant temps, lower egt's and more power.

E-85 typically produces 10-15% more power on the Subarus I've tuned.

E-85 Burns cleaner- reducing emissions

E-85 is cheaper than 85 octane pump gas

E-85 is 105 octane- $2/gal vs $10/gal for race gas

 

Now for the Cons:

Approximately 20% less fuel economy

Less available than regular gas

Fuel quality and ethanol content varies by station

Cold starting is pretty bad- below 30 degrees it will be hard to start (a block heater helps)

 

 

Hope this helps- I'll look for some dyno charts that show the difference between pump and e-85. All of my customers tuned on e-85 couldn't be happier.

[Revolutions Performance]

E-85 is awesome for FP Greens btw.

[VTGT]

I hope Virginia adds ethanol stations at some point. We only have one right now .

 

If I lived in a warmer climate and there were ample ethanol stations it would be a no brainer

[CynicX]

Pros:

 

You can get more power out of the car.

 

Cons:

 

You have to redo the fuel system (easy DIY) I've done it for my turbo upgrade.

 

You have to be loaded filthy rich or willing to tune the car yourself. This isnt something you drive onto a dyno and tell the tuner "I'm going to be running e85 from now on, make me a map chip chop chip" and expect to get it back in 2 hours. I've been helping a friend tune a WRX E85 stock turbo + exhaust for about 2 weeks now. He has a working map but there are MANY MANY hours of tweaking to be done....

[Revolutions Performance]

Pros:

 

You can get more power out of the car.

 

Cons:

 

You have to redo the fuel system (easy DIY) I've done it for my turbo upgrade.

 

You have to be loaded filthy rich or willing to tune the car yourself. This isnt something you drive onto a dyno and tell the tuner "I'm going to be running e85 from now on, make me a map chip chop chip" and expect to get it back in 2 hours. I've been helping a friend tune a WRX E85 stock turbo + exhaust for about 2 weeks now. He has a working map but there are MANY MANY hours of tweaking to be done....

 

 

Sorry, but it takes us less than a day to do a 91 octane map AND an E-85 map. So, yes, you can roll onto our dyno and expect your car back with two different fuel maps in the same day (Providing we don't run into any mechanical issues).

[KGreb]

Where are all you guys that E-85 is cheaper than regular unleaded? I'm in an area (Houston) where we now have 3 stations within 20 miles of my house that carry E-85, but it costs 20-40 cents more than 93 octane. For folks who aren't near ethanol production, it can be expensive.

[Revolutions Performance]

Where are all you guys that E-85 is cheaper than regular unleaded? I'm in an area (Houston) where we now have 3 stations within 20 miles of my house that carry E-85, but it costs 20-40 cents more than 93 octane. For folks who aren't near ethanol production, it can be expensive.

 

We're in Colorado and E-85 is usually around 2.10-2.30/gallon from what i remember.

[mwiener2]

^^ $1.99 when I drove past a station in Longmont this morning

 

We do 91 octane and E-85 dyno tunes in the same session as well. I'll be doing both when I eventually get around to getting my car on the dyno.

 

Cons:

 

You have to redo the fuel system (easy DIY) I've done it for my turbo upgrade.

 

You have to be loaded filthy rich or willing to tune the car yourself.

 

If you already have a turbo upgrade, you most likely just need to put E-85 in the tank and tune for it to work. Doesn't cost anymore than a regular tune. Stop filling the forum with misinformation you troll.

[Boostjunkie]

Anyone with a substantially larger turbo (and not in the thin air of high altitude) will need much larger injectors and a dual in-tank fuel pump or large single external fuel pump to effectively use E85. I easily max out my single Walbro and PE850 injectors on pump gas. E85 needs more fuel flow. If you are actually taking advantage of E85 abilities to produce power, you'll need a substantially upgraded fuel system.

 

Guys who are proponents of E85 will say that it is safe to use, and they are probably right. If they are completely honest they cannot tell you they are 100% certain that it will not cause any longterm damage since no one has run E85 in a Subaru long enough to know for sure (and no, one dude on NASIOC running it for 4 years is NOT proof of anything to me). E85 is a great performance fuel, but it is not a panacea.

 

It's cheap because of subsidies. Take those away and it will cost a lot more per gallon than gasoline. It is no cleaner burning when you look at the complete emissions picture. Good for power, but not a fuel that I consider to be economically viable. For a performance application I'd much rather run an alcohol injection system. Same kind of power gains. No long term durability concerns with the fuel system.

[mwiener2]

It smells funny out the tailpipe too

[Boostjunkie]

You do NOT need dual fuel pumps. A single walbro pump provides enough fuel for 650+ whp on pump gas.

 

No way in hell is a single Walbro good for 650+whp on a Subaru. I've seen a couple Subarus on the Dynojet here with single Walbros dropping fuel pressure around 550whp on race gas. Show me a car making over 650whp on a single Walbro and all you'll be showing me is a really high reading dyno.

 

BTW, I readily admit to having zero tuning experience with E85, but here is a chart I found with stoichiometric ratios for gasoline, E85 and E100. There is a LOT more fuel flow required to properly run E85:

 

Fuel                        AFRst      FARst      Equivalence   Lambda
----                        -----      -----        Ratio       -----
=========================================================================
Gasoline stoich             14.7       0.068        1           1
Gasoline Max power rich     12.5       0.08         1.176       0.8503
Gasoline Max power lean     13.23      0.0755       1.111       0.900
=========================================================================
E85 stoich                   9.765    0.10235       1           1
E85 Max power rich           6.975    0.1434        1.40        0.7143
E85 Max power lean           8.4687   0.118         1.153       0.8673  
=========================================================================
E100 stoich                  9.0078   0.111         1           1
E100 Max power rich          6.429    0.155         1.4         0.714
E100 Max power lean          7.8      0.128         1.15        0.870
=======================--================================================

[mwiener2]

except we don't run 14.7 on gas

 

we shoot for closer to 12 to avoid knock.

 

Becasue of the higher resistance to knock of E-85, you can run alot closer to 9.765. It's significantly more fuel, but not an unreachable amount with one pump.

 

I don't know anyone running 2 pumps for E-85

[LittleBlueGT]

except we don't run 14.7 on gas

 

we shoot for closer to 12 to avoid knock.

 

Who is that comment aimed at?

 

Cause everyone who has participated in this thread lately knows that fact more then you do!

[Boostjunkie]

You are also at altitude. At sea level, one Walbro for a car running on any turbo bigger than say a FP Green is not going to cut it. Even if you are running 8:1 AFR's on E85 as opposed to 11.5:1 on pump gas that is still about 43% more fuel required or 43% less power the same size fuel pump can support. From my experience with Subaru's with a single Walbro, that pump is comfortably good for 550whp, and you can push them up to about 600whp if you have a lot of excess injector capacity. On E85 that means a single Walbro is only good for about 350 legit whp.

[Revolutions Performance]

I've done about 500 uncorrected on a single walbro on several hondas with 1000cc injectors with e85 using a larger fuel pump power wire.

[Revolutions Performance]

Here's one of the cars- I couldn't find the 515 chart but here's one before we turned the boost up a bit more.

 

 

100% STOCK LS/VTEC

-i.e. STOCK LS block with stock LS rods and stock rod bolts, stock GSR head, ARP headstuds

Victor X IM, ITR cams, ITR TB

JG Fab topmount

4" open DP

t3/t67HO (ptrim, .82 ar)

 

1000cc injectors with just a resistor box, intank walbro, NepTune

This car's setup is nothing crazy, very simple, the bottom end was a smoker to begin with http://images.honda-tech.com/set1/smile/emsmileo.gif but it always made good power... he was making 185whp N/A last week. He's planning some internals, but we decided to see what she could do as is until he builds it.

The boost was creeping, the single tial 44m 90* off of the collector is not enough for it to hold steady boost with the open 4" DP. Boost crept up to 15psi of absolute boost pressure. Here are pics and the numbers, consider them equivalent to dynojet uncorrected whp numbers.

 

 

 

 

 

http://www.serviontuning.com/miscellaneous/P1040184.JPG

 

http://www.serviontuning.com/miscellaneous/P1040190.JPG

[mwiener2]

I'm almost positive we've gotten 500whp or more out of single walbro Subarus at Super. I forgot to ask when I was talking to their tuner today.

 

I expect to max out my turbo before I max out my injectors on E-85. I'm at 56% IDC on 91octane and the turbo is pretty much done.

[Boostjunkie]

Perhaps I was somehow unclear... anyone who has tuned a few cars will tell you that Subarus have a higher BSFC than some other popular import tuning platforms. So I don't find it all too surprising that more power has been made on a single Walbro on other cars. However, given that this is a Subaru enthusiast site I found it most pertinent to reference my experience with Subarus, not Hondas.BTW, I did also say that a single Walbro was good for 550whp or more on gasoline. Oh and mweiner, those are some very low idc's. I hope you were tuned very lean, otherwise that little fuel would indicate that you aren't flowing very much air and therefore making a pretty modest amount of power.

[Vimy101]

Ethanol is mostly a con for the economic reasons cited though looks like guys are having some gov't subsidized fun with it. (Isn't that kinda like Iraq? )

 

Interesting thread.

 

PS Sorry for the current affairs forced injection but I couldn't resist since it's all part and parcel of "energy independence".

[mwiener2]

nah, I just have 850cc injecotrs and modest size turbo. It usually runs too rich most of the time

[CTlegacy06]

How does E85 do with nitrous or meth, does it react the same as regular fuels?

[mwiener2]

^ yes, but you need even more E-85. In that case you would def need two pumps and probably extra injectors too.

[Boostjunkie]

^ yes, but you need even more E-85. In that case you would def need two pumps and probably extra injectors too.

 

That might be true with nitrous but that is not true with alky injection. Since there is already a very large amount of alcohol coming through the injectors and E85 is a fairly high octane fuel so the octane enhancement that usually come from alky injection with pump gas would be largely nulified. If I were running E85 I'd just inject water, using it's superior latent heat of evaporation to pull out as much heat as possible from the intake air charge. That would allow more boost and timing to be run (within reason)