Powerquest230

I understand that ethanol blended fuels are less than desirable but we'll be stuck using them until some folks pull their heads out of their arses. I know that ethanol produces less energy than gasoline and we see how this affects gas mileage, it would be interesting to the see the diminished horsepower levels.

Has anyone ever run a dyno test using the same engine running on the identical octane fuels- no ethanol, 5% ethanol, and 10% ethanol? If you could point me towards that thread or report I would appreciate it.

Thanks,
Rick

DMOORE

I remember reading where a flex fuel vehicle will make about 15% less HP when running E85 compared to regular gas.


Darrell.

ezstriper

E85 and the blends we see are not the same....E85 produces more power, but you burn more....the 10% blend that we are dealing with not seen anything H/P wise...you also cannot just put E85 into anything not set up to run on it..

CigDaze

In order to make more power using E85, you have to increase the fuel consumption (flow rate) a minimum of 39% over that of gasoline, and in conjunction with that the compression ratio must also be increased - you need a dedicated, purpose-built engine to take full advantage of E85 and subsequently this engine can NOT run straight gasoline else you will detonate it to pieces. Bottom line is that any engine that is designed to accept regular gasoline will never net equal power output, nor the fuel economy running E85.

Regular gasoline has a potential energy content of 114,100 BTU/gal, while E85 contains 81,800 BTU/gal.

That's damn near a 30% drop in power output given equal compression, timing and fuel flow.

A modern automotive engine's ECU can compensate to some degree using variable valve timing and adjusting fuel flow to compensate, however without increasing compression ratio, an engine will never make more power on E85 than straight gasoline.

articfriends

iTrader: (1)

As far as dynoing with ethanol vs non-ethanol, I have been on the dyno quite a few times and until last year I could still get non-ethanol premium but I purposely dynoed WITH ethanol gas so motor would be fuel safe. As far as back to back comparisons, can't help you there, Smitty

ezstriper

Had say this but you are wrong, a engine setup with either higher conpression in a N/A setup or more boost will make more power as E85 octane will allow this and will produce more power..period ! we have tested this and power levels were very good...no you can't just dump it in..but when done for it will make more power than pump gas..

FuelinAround

We have done more than one test of this through our race fuel company. On average the fuels did not increase on HP but did have more torque. These were with blends ranging from 6%-8% and Chevron fuels.

DMOORE

The key here is more compression, or more boost. If an engine, such as a Flexfuel motor, is tested with no changes to it at all, it will produce less power with the e85. There is simply less BTU's in e85 compared to gas.
You are correct in the fact that is one is able to take advantage of more compression or boost E85 will always make more power over pump gas due to it's higher octane.


Darrell.

mcollinstn

Not exactly.....
A typical gasoline engine (jetted properly) burns about 0.50 lb of gas per hour per hp. Same engine running on E85 (with jetting and a small increase in ignition timing to match) burns about 0.65 lb of E85 per hour per hp.

Typical gasoline weighs 6.1 lb per gallon.
E85 weighs 6.6 lb per gallon.

A typical engine putting out 100hp will burn 50 lbs of gas per hour (this is 8.2 gallon per hour).
Same engine tuned properly for E85 will burn 65 lbs of E85 per hour (this is 9.9 gallon per hour).

Gentlemen, this is a 21% increase in "fuel consumption" as measured in fuel used per time unit.

This is a far better deal than the suggested "39%" increase in fuel rate.

Additionally, in pretty much all engines over 9.5:1 compression, E85 produce equal hp with only fuel jetting and basic ignition timing adjustments. Nothing dramatic, but certainly not a REDUCTION of available hp. In any engine that is equipped with a knock retard, E85 will consistently make more hp than gasoline in hotter, humid conditions as well as in cold dense air situations (providing that the engine is jetted and the ignition is adjusted for E85).

Now, if you do not bump the timing and make certain that the engine receives the required fuel volume, then you will end up making less power - that's a given. But for such minor adjustments, the results are very acceptable.

This in no way constitutes a recommendation for people to swarm to become E85 converts. It is just my attempt to quell some bad information that is floating around.

Now, let's talk about performance motors. Start bumping the compression or adding boost to where premium unleaded is no longer adequate, and E85 becomes an even MORE desirable alternative with its high effective octane number (105).

In absolutely ALL cases of turbo/supercharging/high static CR - E85 (when properly tuned to match) will produce more HP from the same engine as pump gas will.

I don't run E85 in anything of my own...
Yet.

I've run race gas in things that needed it. While expensive, race gas is easy to tune with, delivers consistent performance, and requires no odd practices for engine longevity.

I've run exotic stuff such as Nutec and other really amazing fuels, but they require being flushed immediately from the system else you will regret it.

With the dropping cost of E85 and its performance benefits, it has become a very real and interesting option.

I believe E85 will burn with a visible flame, so you don't run the risk of being burned alive invisibly like you would with straight corn juice. The fuel system modifications needed are very well known and easily done.

I don't consider E85 to be the evil witch's brew that some others do.

MC

mcollinstn

There is definitely less BTu's in a unit of E85 than there is with gas. BUT if you squirt MORE E85 into the motor, you end up with the same BTu per compression stroke, and you end up with similar power.

Most FlexFuel vehicles deliver similar performance on both fuels. The E85 maps are usually biased towards a lot of ignition lead and lean fuel metering. The ignition lead gives snappy throttle response and a little more peak torque than the gas map. The lean fuel settings give up some hp in exchange for a little better E85 fuel economy than what would be optimal. The result of the lean E85 map is a little less hp than gas, and still worse fuel MPG but not as bad as if the fuel settings were optimal for the E85.

There are plenty of E85 performance "maps" available on the aftermarket for modern hotrod cars. All of these are "plug and go" with no internal engine mods required. While it is obvious that all of the turbo and supercharged cars would clearly make more power on E85, the N/A maps are giving consistent and real performance increases. Corvette Z06, Mustangs, LS powered trucks, Camaros, etc - go buy a E85 map, load it into the computer, pour E85 in the tank, and you've just added a kick in the pants that you cannot deny.


Yes, yes, yes..... you also get right at 20% less apples-to-apples fuel economy, and as we all know - when you get a hp bump, you keep your foot in it more often to enjoy the feeling and your fuel economy vanishes due to the "hey watch this" phenomenon.


MC