Can one use E85 petrol in std. ABY S2?

[macspring]

This may be covered elsewhere, but here goes. E85 petrol is available locally and has an octane rating of 104.

The query is, can it be used 100% neat or 50:50 with say 95 unleaded petrol?

Or are there side effects like too glutinous in its viscosity or that it may damage seals or rubber in the fuel system of an ABY S2?

The engine is standard except for a chip ?

Any comments gratefully received.

Thanks.

[S2central.net]

EspenW is the expert on this stuff - he runs it on his RS2 but had to modify the fuelling to make it work. Its damn great stuff the E85 - forget the ecoballs - it has knock resilience than petrol courtesy of that RON/MON... but you need more of it injected than petrol for other geeky chemical reasons - different BSFC (google it) - similar to when running on something like Ethanol. Isn't E85 like 85% EThanol and 15% petrol ?

I think Espen runs with a variable pressure regulator on his car on what I think is otherwise stock engine & ECU. He setup the AFR with WB02 to get the pressure right. Seek out some posts from Espen - he has mentioned his setup more than once - I could be getting it wrong.

With your MTM chipset you might get further gains as you should have more advance than stock... I'd be interested in dialling in some more though to see how much more timing can be had with this blend of rocket fuel. I heard it was getting more commonly available down Sout - but I've not seen it yet in the North.

Related article on E85 and back-back tests - NOT Audi application... http://www.iop.org/activity/groups/s.../file_8795.pdf

I bet you could safely add say 5-10% E85 into a tank of petrol to try it out... but you'll need an AFR guage to see whats going on.

[S2central.net]

By total fluke - reading that Lotus presentation in more detail... They upgraded a 162kW engine to E85 - thats about 220bhp. Note how they went from 300cc to 425cc injectors with E85 and needed two more injectors. I don't know what fuel pressure they had, but it smells like going up to 440cc injectors might on the S2 might be a starting point... You don't want silly high fuel pressures if you can avoid it with small injectors - puts extra strain on your pump as well as fuel lines.

On the old spreadsheets I could probably work this out more accurately - see how the Lotus boys have their homework done with mass of fuel required across the rev range - I'd need to research it more - not done calcs on E85 before.

[macspring]

Thanks, Paul.

While the benefits are there to be had, the method of accessing them seems too hard, (for me).

Especially as I find it hard to get time to wash it.

Thanks though.

[driftin jo]

You need to inject about 40% more fuel than normal to get the mix right and there are numerious other things to consider.

The ethanol in the e 85 will distroy any rubber fuel lines you have in your fuel system,
it will also start to attack any bare aluminium parts as well.

Another scary thing that is often overlooked is that the fuel pump must be capable of operating with electrically conductive ethanol instead of non conducting petrol !
Im not sure if the fuel pumps used on the s2 are ok or not for 100% E85,
chance it at your own risk !!

One good thing i use e85 for is passing emisions tests, just get the car nice and warm (a quick blast round the block or two) have the tank low on fuel and then pull up and add about 25 % to your tank. Then take it straight to the mot place WITHOUT doing any WOT / BOOST driving or you may melt a valve!

This will lower your co way down and your s2 can pass without a cat no problem, well it works for me anyway.

My co was 83 and it had to be 20 or less, i put approx 25% E85 in and took it back to the mot place and my co was 13 !
when the mot is done just drive iot slowley to the petrol station and fill it full you will have diluted the e85 enough to drive flat out again !

The ethanol in the E85 essentially introduces extra oxygen to the fuel and helps it burn more of the carbon in the fuel so much cleaner.

[S2central.net]

Hmmm - intersting info there Jo, but I don't recall Espen having to change fuel lines or fuel pump with E85. I just assumed it had enough additives to be used on same engine instead of petrol. I never knew it was conductive though.

PS - Nice MOT trick there BTW...

[GazzaG60]

E85 has a different AFR target range too i believe. thats why it cant go straight in.

drinks more to produce more but its cheaper.

[k.alle]

You need to inject about 40% more fuel than normal to get the mix right and there are numerious other things to consider.

The ethanol in the e 85 will distroy any rubber fuel lines you have in your fuel system,
it will also start to attack any bare aluminium parts as well.

Another scary thing that is often overlooked is that the fuel pump must be capable of operating with electrically conductive ethanol instead of non conducting petrol !
Im not sure if the fuel pumps used on the s2 are ok or not for 100% E85,
chance it at your own risk !!

What you mention here is a common misconception.
E85 is no more aggressive on rubber/fuel lines than gasoline is.
This has been proved time and again.
E85 is a very good solvent though, and when you use it long enough it cleans out all gasoline residues and debris that has been collected over the years, so some people can suddenly see a seeping fuel line.
It is NOT the ethanol that has eaten through the metal/rubber it is the ethanol that has cleaned away any debris/residue that might have covered a tiny tiny hole hence starting to went to leak.
This would have happened sooner or later when going on gasoline as well.

I think this misconception mainly comes from the car industry who wants to sell E85 specific cars and not let people convert their old cars and be happy with it.
It also comes from people who has little IRL knowledge about the fuel and other lobbyists.

People often confuse E85 with methanol which is a very very aggressive alcohol, but also very good for tuning like Funny Car's and such.

E85 stands for = Ethanol 85% & Gasoline 15% as you said Paul.

It's very good for slipping through MOT's especially the HC values improves.
Last year I had 140HC and got failed, I didn't find the problem so I MOTed on E85 = 13HC, found out it was the MAF by the way.


Usually you can try and mix it with regular 95, the limit is usually ~30-40% E85 and the rest 95 octane.
You notice when the car is starting to feel a bit dull, there's your limit you wont hurt the engine.

Loads of people has converted to E85 here and in Norway, and I have never read about any mishaps concerning the fuel pump.
Though the fuel pump is a unknown territory for me with E85.

[driftin jo]

The rubber used in audi's is probably quite tolerant to the ethanol in E85 as you say its prob more due to it being old to start with.

I would not of thought that running an S2 with ~30-40% E85 mixed in your petrol was a good idea as you are going to make it run lean, there is less carbon and more oxegen in ethanol than petrol hence why you run much heavier mix about 9.76 for stoich as apposed to 14.7 for petrol.

With a turbo car it is very bad to be run lean , well it is if you have your foot to the floor a lot !
Are you saying that you personally have run ~30-40% E85 in an S2 with no modifications and driven it flat out ?
I recon you were lucky you haven't melted a piston if you have.

[S2central.net]

The only guy I know who has tested it properly in S2/RS2 is EspenW - where are you big man - he hiked up the fuel pressure to get round this problem of running too lean otherwise - he doesn't have custom chips to do that - and I think he dials the pressure back to normal if he can't get a refill of E85.

Earth calling planet Espen - are you there ?

[k.alle]

The rubber used in audi's is probably quite tolerant to the ethanol in E85 as you say its prob more due to it being old to start with.

I would not of thought that running an S2 with ~30-40% E85 mixed in your petrol was a good idea as you are going to make it run lean, there is less carbon and more oxegen in ethanol than petrol hence why you run much heavier mix about 9.76 for stoich as apposed to 14.7 for petrol.

With a turbo car it is very bad to be run lean , well it is if you have your foot to the floor a lot !
Are you saying that you personally have run ~30-40% E85 in an S2 with no modifications and driven it flat out ?
I recon you were lucky you haven't melted a piston if you have.

The rubber in most cars is very resilient to E85, as a gasoline certed hose is almost automatically certed for Ethanol as well.


No I have not done that with the S2, when I wrote usually I meant that in general this applies to most cars.
It is the language barrier here, I'm sorry if I confuse you.

It is being tested constantly over at NordicAudi.com (and all over Sweden, not just Audi) to run a E85 to a certain degree on unmodified member cars just using different mixing ratios till you find the sweet spot.


If I were to use it with my S2 I would do it properly and up the fuel with ~33-35% and give it a go, with AFR meter of course.

[EspenW]

Most cars made after approx 1985 will have a fuel system that is tolerant to ethanol, as E10 became common (especially in the US) at that time.
There is no guarantee that a car made after that will not see problems, but it is pretty unlikely, based on testing done all over the world.
Car manufacturers want to sell a new flexifuel car, and oil companies want to keep selling oil based fuels, thus, the myths live on.

I have been running E85 in my 1986 Golf since 2006 and in my RS2 since 2008. No problems besides cold start issues.
A naturally aspirated engine will see power and torque gains of approx 5% just from switching fuels (running the proper AFR of course). A turbo car running high boost can see much more than that. The octane rating of E85 is approx 104, but more interesting, the effective octane is approx 115 due to extreme cooling effect. E85 @ 20deg C has approx. the same cooling effect as petrol @-50 degC.

In my RS2, I run a Turbonetics E50 turbo w/proper software (turbo rated to approx 480hp on 98 octane fuel). My setup for running E85 is as follows:
Bosch 044 pump in tank (fed by 14.5v)
Siemens 630cc injectors
Adjustable fuel pressure regulator
Innovate LC-1 wideband

Besides a Milltek 3" catback, the rest is stock ADU.

With E85, I run a fuel pressure of approx. 3.6bar. In case I need to run on straight petrol, I lower the fuel pressure to a little over 2 bar. Mixes of E85 and petrol means fuel pressure anywhere in between.

Massive gain on my car, especially torque. Torque (measured in 3rd gear) was 447nm at the wheels on 99 octane, but skyrocketed to 550nm at the wheels on E85. That translates to a pretty violent amount of torque at the flywheel.
Power went from 368hp at the wheels on 99 octane to 395hp at the wheels on E85.
Max G-Force in 2nd gear went from 0.67G on petrol to 0.84G on E85.

E85 requires an increase in fuel flow of 30-40%. The first thing to get is a wideband lambda. With that in place, one can experiment with how much E85 is tolerated before AFR under boost goes above approx 12:1. Next step is larger injectors and an adjustable fuel pressure regulator (with gauge).

Attached are graphs showing torque and power measured at the wheels on 99octane vs E85.

[S2central.net]

Thanks Espen - if E85 becomes widely available here I will jump on it - the upside looks fantastic

[k.alle]

It is just that Paul, fantastic.
When I go custom map E85 will deffo be on top of the list..

[macspring]

So EspenW,

If one only has access to 95 octane petrol and one wants to effectively increase the octane to say 98/99, is it fessible to leave the car completely stock with no Air / Fuel Ratio gauge or anything else and put in say 10 or 20 % of E85 per tankful?

Or should one just stay away from such activity and drive on 95 octane and do not attempt to be "greedy".

To keep it as simple as possible for me, if one wanted to drive a chipped ABY on 100% E85, what changes does one have to make to the car?

If they could be listed in numbered point format, that 's good for me.

Thanks for your time.