E85/ Eflex and its affect on avcs

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E85/ Eflex and its affect on avcs

Postby dr20t » Wed Aug 14, 2013 8:45 am

I have been doing some research and wanted to use this as a point of discussion since our understanding and usage of e85/ eflex fuel is relatively rudimentary at this stage, in my view

For those unaware, e85 or eflex (Caltex Australia's version) is a type of fuel that contains 85 percent ethanol and 15% gasoline (eflex having between 70-85% ethanol and the remaining contet being standard petrol)

Here are some links from our own site for those wishing to do some light reading on the benefits etc:

viewtopic.php?f=56&t=15638

viewtopic.php?f=16&t=21043&start=0

viewtopic.php?f=2&t=11296


As some of you may know, I've been running eflex now in my car for exactly one year (although 4 months of that my car was off the road having work done).

So having some basic understanding of majority ethanol based fuels, I have been exploring the upside potential that the cleaner burning, lower energy combustion of eflex provides.

So far this is what I know :

- ethanol has a lower amount of energy per unit (about 40%less) than normal unleaded petrol (95 Ron).

- because of this, to make the same power at any given point as an engine running on normal fuel, a blend of 85% ethanol to 15% petrol will require approx 25- 30% more fuel to be burnt.

Eg - car A requires 250cc per min to make 100kw at 5000rpm.

Car B with an identical mechanical setup to Car A running eflex will require approx 325cc per minute of fuel to make
100kw at 5000rpm

So generally speaking, your fuel usage will increase and mileage decrease with ethanol fuels all else being equal - which is an important point - ill get to it in my theories/ ramblings below.

- the cooler burn of ethanol fuel allows more ignition timing advance / boost and a general increase in combustion chamber pressures before detonation threshold is reached. These are basic mechanical concepts beyond the scope of this post so if these are unfamiliar to you, some info can be found on google (its great).

- the slower burn characteristics of ethanol fuel allow it to resist pre ignition induced detonation

- turbo / supercharged vehicles love ethanol fuels - they respond much more acutely to it than naturally aspirated vehicles, because typically, a forced induction vehicle's intake charge temperature is alot higher than ambient, and the cooling effect of ethanol (given its high alcohol content) dramatically assists in reducing this charge temp once the fuel is injected into the air stream in the manifold/ plenum runners. Therefore the rate of change that is noticed is alot larger in forced induction vehicles due to this element, in my opinion.

- ethanol is high in alcohol which means it can hold and infact attracts water content readily. In this sense, it can be a cause of oxidisation in certain mechanical parts if water absorption has occurred in the fuel tank or fuel lines etc.

- ethanol (like petrol) is a solvent although in a stronger form. This means in the combustion process, any unburnt or excess fuel (there will be some) can make its way into the lubrication system, and thus reduce the effective lifespan of your engine oil, as it breaks down the esters and oil polymers alot quicker due to its solvent qualities. I reccomend changing oil as soon as every 3500kms or as late as every 5000kms if running ethanol fuel, and ensure your engine oil is API SN compliant for ethanol usage.

So now that we have established some of the above, I want some discussion on some untapped benefits of using ethanol fuels. More specifically, I'm exploring how we can:

1. Generate greater engine efficiency
2. Extract more power from the engine when running ethanol fuels apart from adding boost / timing.
3. Reduce our emissions footprint

Want to get even more granular? I'm talking about avcs.

Avcs is Subaru's variable valve timing system - this allows for continuous adjustment of inlet (and in some cases, exhaust) valve opening, to extract maximum efficiency, torque and emissions control (exhaust gas recirculation of the 21st century)

My theories / questions / ramblings :

- From my research, e85/eflex is a cooler fuel, as established above.

- The alcohol content has a denaturant (so no this wont be an acceptable substitute for vodka)

- because ethanol absorbs / contains more water per unit than petrol, it produces less hydrocarbons in the combustion process ( or my thinking is maybe it dilutes the hydrocarbons in the the exhaust because of the water content???)

- water content of burnt e85 is roughly 28% compared to 11% in petrol. This creates greater moisture in the exhaust. By using avcs overlap, volumetric efficiency can be improved, and instead of just being an egr mechanism, I want to use overlap to cool the intake charge further given the higher water content

This effectively give a cleaner, cooler, denser burn and improve fuel efficiency (the ultimate goal being to get the same fuel efficiency as a petrol car ie reduce fuel consumption by the stoich 20% difference)

Discuss please :)

Mick
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Re: E85/ Eflex and its affect on avcs

Postby coyote » Wed Aug 14, 2013 9:08 am

You forgot about the oxygen content of ethanol.

It's important to this discussion.
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Re: E85/ Eflex and its affect on avcs

Postby dr20t » Wed Aug 14, 2013 9:11 am

coyote wrote:You forgot about the oxygen content of ethanol.

It's important to this discussion.


Indeed I did coyote - was definifely in my mind - need to edit - will do late
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Re: E85/ Eflex and its affect on avcs

Postby brainy » Wed Aug 14, 2013 3:46 pm

maybe also discuss the current pricing vs P98?

E85 last i saw was $1.39 per litre.... Seems to be higher than what i remember when using it.

Finally, e85 wear and tear on engine components? Possible discussions about maybe requiring nylon fuel lines?
Cold start concerns that people may experience?
Not sure if these are within the specs of what you want to explore
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Re: E85/ Eflex and its affect on avcs

Postby dr20t » Wed Aug 14, 2013 4:49 pm

brainy wrote:maybe also discuss the current pricing vs P98?

E85 last i saw was $1.39 per litre.... Seems to be higher than what i remember when using it.

Finally, e85 wear and tear on engine components? Possible discussions about maybe requiring nylon fuel lines?
Cold start concerns that people may experience?
Not sure if these are within the specs of what you want to explore


Thanks brian

To be honest I'm looking more to open up ideas on how eflex is untapped potential for new frontiers - beyond just bumping up boost or timing

On price, yes it's gone up but its still cheaper than 91 with e10, although again this is not the aim of this thread as people can look pricing and availability and some of the basics up quite easily.
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Re: E85/ Eflex and its affect on avcs

Postby Rich_D » Wed Oct 02, 2013 2:37 pm

Eflex here in Canberra has been consistently around the 75% ethanol content and I have been testing frequently.

The only thing I specifically upgraded/changed for the Eflex conversion was the fuel pump, injectors and a new fuel filter.

As for cold starts, I think with the extra petrol in the fuel helps. I haven't had any problems on -5 deg mornings :)

I'm currently going to change the oil I use from Mobil Delvac MX to ULX110 after alot of discussion - I will be however getting the Delvac and ULX110 tested to see how it holds up.

As it stands I have been running Eflex for 8+ months now on a daily driven car - 326.4kw on 19lb. (Last dyno run)

I'm still getting less KM's than on 98; that being said I was only running 220kw before the rebuild and then I ran 98 for a while after the rebuild (280kw on 18lb)
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Re: E85/ Eflex and its affect on avcs

Postby Rich_D » Thu Oct 10, 2013 4:02 pm

Rich_D wrote:Eflex here in Canberra has been consistently around the 75% ethanol content and I have been testing frequently.

The only thing I specifically upgraded/changed for the Eflex conversion was the fuel pump, injectors and a new fuel filter.

As for cold starts, I think with the extra petrol in the fuel helps. I haven't had any problems on -5 deg mornings :)

I'm currently going to change the oil I use from Mobil Delvac MX to ULX110 after alot of discussion - I will be however getting the Delvac and ULX110 tested to see how it holds up.

As it stands I have been running Eflex for 8+ months now on a daily driven car - 326.4kw on 19lb. (Last dyno run)

I'm still getting less KM's than on 98; that being said I was only running 220kw before the rebuild and then I ran 98 for a while after the rebuild (280kw on 18lb)


Unfortunately - the ACT and Caltex in particular are shit and now only one servo sells eFlex and it's too far away from my place to be economical so I'm switching back to 98.
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Re: E85/ Eflex and its affect on avcs

Postby bass_straitener » Thu Oct 10, 2013 4:23 pm

Predicted the end of supply and scale back of Caltex eflex 6 months ago via a very reputable industry source.

http://forum.liberty.asn.au/viewtopic.php?f=45&t=20993&hilit=woolworths&start=15
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Re: E85/ Eflex and its affect on avcs

Postby BUDDAH » Thu Oct 10, 2013 4:42 pm

3. Reduce our emissions footprint


BULL SHIT you must be a Greens :roll: voter
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Re: E85/ Eflex and its affect on avcs

Postby coyote » Thu Oct 10, 2013 5:02 pm

bass_straitener wrote:Predicted the end of supply and scale back of Caltex eflex 6 months ago via a very reputable industry source.

http://forum.liberty.asn.au/viewtopic.php?f=45&t=20993&hilit=woolworths&start=15


Woolworths were never going to let it succeed. I'm surprised the project has last this long.

They are not interested in innovation, only selling the shittiest product for the highest price. They want to meet their ethanol quotas by using it as an octane booster in the worst sludge they can find and selling it to their hordes of docket collecting fly by card holders to put in their Camrys.

It's a shame, but hopefully United can continue to carve out a niche market and do well from it. I'm already supporting them, but for my ethanol fuel and the crap I put in my daily beater.
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Re: E85/ Eflex and its affect on avcs

Postby bass_straitener » Thu Oct 10, 2013 5:20 pm

coyote wrote:
bass_straitener wrote:Predicted the end of supply and scale back of Caltex eflex 6 months ago via a very reputable industry source.

http://forum.liberty.asn.au/viewtopic.php?f=45&t=20993&hilit=woolworths&start=15


Woolworths were never going to let it succeed. I'm surprised the project has last this long.

They are not interested in innovation, only selling the shittiest product for the highest price. They want to meet their ethanol quotas by using it as an octane booster in the worst sludge they can find and selling it to their hordes of docket collecting fly by card holders to put in their Camrys.

It's a shame, but hopefully United can continue to carve out a niche market and do well from it. I'm already supporting them, but for my ethanol fuel and the crap I put in my daily beater.



Actually, the reason for the discontinuation of eflex is simply because they're not selling enough of the product to make it worthwhile longer term to continue with expansion or management of existing infrastructure.
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Re: E85/ Eflex and its affect on avcs

Postby coyote » Thu Oct 10, 2013 5:35 pm

bass_straitener wrote:
coyote wrote:
bass_straitener wrote:Predicted the end of supply and scale back of Caltex eflex 6 months ago via a very reputable industry source.

http://forum.liberty.asn.au/viewtopic.php?f=45&t=20993&hilit=woolworths&start=15


Woolworths were never going to let it succeed. I'm surprised the project has last this long.

They are not interested in innovation, only selling the shittiest product for the highest price. They want to meet their ethanol quotas by using it as an octane booster in the worst sludge they can find and selling it to their hordes of docket collecting fly by card holders to put in their Camrys.

It's a shame, but hopefully United can continue to carve out a niche market and do well from it. I'm already supporting them, but for my ethanol fuel and the crap I put in my daily beater.



Actually, the reason for the discontinuation of eflex is simply because they're not selling enough of the product to make it worthwhile longer term to continue with expansion or management of existing infrastructure.


Chicken and egg, Bruce.

Without proper distribution, it's not a viable product for the consumer. By not allowing it in the W branded stores, there was never going to be proper distribution. In Brisbane, it stops about 20km south of the CBD. Forget driving to the Sunshine Coast (although you pass at least a dozen Caltex's). Their refusal to carry ensured it couldn't work.

Had they rolled it out properly, it "may" have been a different story. When you can't drive across town and buy fuel, it was doomed to fail. Never had a chance.
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Re: E85/ Eflex and its affect on avcs

Postby kiahatsiu » Thu Oct 10, 2013 6:55 pm

So when is this phase out happening?
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Re: E85/ Eflex and its affect on avcs

Postby dr20t » Thu Oct 10, 2013 7:47 pm

Good stuff mentioned here guys

At the risk of sounding unappreciative of the input, I was hoping we could keep this thread to the more technical side of e85 and the positive impacts on combustion / power / efficiency
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Re: E85/ Eflex and its affect on avcs

Postby coyote » Thu Oct 10, 2013 8:15 pm

Sorry Dad.

On a technical note, United consistently tests at over 90% up here ... so EFlex won't be missed much.
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