Contemplating Different Ethanol Blends .

[discopotato03]

Hi all , I was crunching some numbers to see how difficult it would be to make an E50 blend just to try . I'm not totally convinced that ethanol ratios of 70-85% are necessary in a medium powered road Skyline and I did some searching to see what others think of this .

I found this American thread and it was most interesting to read about "blender pumps" that can make up varying ethanol blends overseas .

http://www.dsmtuners.com/forums/tuning-engine-management/418047-using-lower-percentages-ethanol-e20-e30-e50.html

I haven't gotten all the way through that thread yet but it was mentioned that even when the octane rating of certain blends matched straight petrol the ethanol blends tended to be more detonation resistant . I guess its the evaporative cooling of ethanol at work here .

Just for the record by my calcs and assuming an R33 has a 55L fuel tank you could possibly add 39.3L of EFlex which is 27.51L ethanol and top off with 15.7L of petrol to get your 55L of E50 .

It may be possible to go even lower in Ethanol than 50% , with the right AFRs , and not have to pull too much timing losing burning efficiency and torque .

The one big variable is the octane rating (detonation resistance) of the ULP being used in these potential blends .

It would be interesting to try 95 and 91 ULP just to see how far the still higish percentage of ethanol can supress detonation .

I realise this is a bit of a screw around and you'd need to be carefull to keep the blends accurate , sounds like an ethanol content sensor and read out would be the safest bet .

Something to think about , cheers A .

[KiwiRS4T]

Why would you bother unless there is a big cost saving.

[Manuel Kasko]

Yeah what he said ^

Also good luck getting your tank completely empty each time you need to fill up.

[bradsm87]

I'm going to buy straight ethanol from Just Fuel (only 10c/l more than pump E85) and mix it 1 part ethanol to 2 parts BP Ultimate (33/67 mix). This will give me enough ethanol in the mix to make peak torque without detonation while keeping a majority of normal petrol so easier cold starts, less oil dilution and longer lasting engine IMO.

[Piggaz]

Sounds like too much hard work.

Decent ecu and a Ethanol Content Sensor. Done.

[discopotato03]

That thread I linked above digs some pertty deep holes when it comes to the petrol quality that could be going into these E70-E85 type fuels .

That aside can some mathematically minded person come up with some sort of formula that would allow us to work out injector trim numbers for diferent Ethanol content fuels ?

I use 740s which are double the size of the std 370s so my PFC trims would be 50 for petrol and 65 for E70 - assumes I need 30% extra fuel because of the different heat values of the high Eth content fuel . Just trying to calculate what E50 would need in the way of injector trim numbers .

Thanks in advance , cheers A .

[AngryRB]

why would you gamble like that, last thing you want when your bouncing off the limiter is the worry of diluted ethanol keep it rich and smelling sweet i say

[discopotato03]

The answer hit me a couple of hours ago .

Making the assumption that an E70 blend needs 30% more fuel than ULP then E50/E70 = 0.714 times my 30% = 21.428 .

Because my Nismo 740s are twice the std 370 size I use a 50% correction factor which means I cut above 21.428 in half (10.714) as well then add that to the 50 to get an injector trim figure of 60.714 - 60.7 .

Mine is a pure road car and I have no interest in bouncing it off its rev limiter .

When you consider that the majority here are probably using 98E0 , 95E50 or 98E50 in the right AFRs has to be better .

A .

[discopotato03]

This is an interesting if time consuming read into fuel standards in the US .

http://ethanolrfa.3cdn.net/dd9e74ce1c454a97cc_rbm6bdgh3.pdf

If at all interested in fuel I suggest you read it

Cheers A .

[rob82]

I'm going to buy straight ethanol from Just Fuel (only 10c/l more than pump E85) and mix it 1 part ethanol to 2 parts BP Ultimate (33/67 mix). This will give me enough ethanol in the mix to make peak torque without detonation while keeping a majority of normal petrol so easier cold starts, less oil dilution and longer lasting engine IMO.

Nothing wrong with this approach at all...

There is no need having a higher octane level than is what's required to make the desired torque. Especially when you are increasing your bsfc with a lower density fuel.

I didn't loose any power on an evox when going from an optimized e85 tune to a 50:50 mix of e85 and bp 98oct. And that was running close to 2bar of boost.

Edited November 10, 2012 by rob82

[KiwiRS4T]

Nothing wrong with this approach at all....

If you like to spend your spare time mixing fuel

[discopotato03]

Actually if you could get a graduated container or something that filled to virtually the same exact amount and used it for the E70/E85 fuel component I reckon you could get a repeatable blend .

In that seciond link I posted above they speak about how the Ethanols octane rating is not an accurate one and it isn't a good indicator of a fuels knock rating anyway .

Someone in the thread these links come from reckons that in concentrations at/above 50% the actual octane of the petrol content becomes less critical .

More later , cheers A .

[discopotato03]

For better or worse I tipped in 15.3L of Ultimate 98ULP and topped up with EFlex so I should have something close to E50 now .

I reckon EFlex is a pretty forgiving fuel and it'd be simple to start with 15L of 98ULP and the rest EFlex , provided the pump numbers were reasonably accurate and you were not tuned to the bleeding edge its probably good enough for road though monitering with a wide band would be good .

I guess if you use less ethanol the percentage variation becomes less of an issue and the PULP you add is more of a known quantity/consistancy .

I'm not sure if its known what United and Caltex use for the other 15 to 30% of their FF blends and it probably doesn't have to be anything brilliant in those percentages . This would be one area where drum E85s should be a known quantity . Not something for everyones garrage ...

Anyhow as luck would have it my current best EFlex maps were just starting to give more acceptable consumption and that was from getting the shits with chasing better range and going for better drivability and performance .

Anyhow the fuels mixed in reasonably quickly and I drove for about a km before the wide band indicated richer in Lambda and I uploaded a map with different injector trims to suit with Datalogit . I went from 65.0 to 60.7 though its still a little rich so will fiddle again later this morning .

It will be interesting to see if performance changes at all which is unlikely for a "light tuned" roadie and if my range increases which it should . If all goes well I may be able to up the ratio to 60% PULP (E40) and see where that takes me .

Not that too many care but for the record 40% of 55L is 22L and 31.5L of E70 in theory has 22.050L of ethanol .

Whats life without challenges

[GTScotT]

Why not just carry a 15L jerry of e100 and pop that in on every fill from empty, then 30L of 98.

Simon blends his E85 50/50 with 98, dubs it e42.5 lol. So its far from impossible or necessary to run big e content.

[SimonR32]

Why not just carry a 15L jerry of e100 and pop that in on every fill from empty, then 30L of 98.

Simon blends his E85 50/50 with 98, dubs it e42.5 lol. So its far from impossible or necessary to run big e content.

Yeah we have never had issues using the "jew mix"... It works and it works well!

Only hassle is the actual mixing of the fuel, if you work out a quick easy way to do that then bob is your aunty

[discopotato03]

Yeah wouldn't have a problem with that if I could buy pure fuel grade ethanol in Sydney , is that possible ?

I'm just not convinced that some gain a lot from the short range disadvantages of E70 -E85 , on the street anyway . There would be a sweet spot trade off of ethanol percentage for daily road use but I don't want to make a guess what that is at this stage .

I've only had one day of HippE50 and I can feel positives with no negatives . All the right down low running is more torquey IMO and it makes me think the lower heat value of ethanol in high percentages is a disadvantage here . My guess is that you can't get the same combustion temps and therefor pressures when an engine is using bugger all air and throwing in more ethanol doesn't seem to make up the temp difference .

I think my car has some issue when running on boost but it tries to boost earlier and harder for the same throttle positions on HippE50 than wth pump e70 .

Its certainly going through less juice with it and I'm looking forward to seeing over 100 Km for the first quarter of a tank .

Something thats probably not possible to know is what United and Caltex are using for the petrol content of their E85/E70 . I have been reading that Australia has been recently developing standards for "E85" so that there can be some degree of quality control . Standards reckoned that until recently these fuels were unregulated and its hard to imagine the producers not leaning their own way with things like "base stock" used as the ULP component .

Its worth reading up on vapour pressure and why ULP and Ethanol blended fuels are altered seasonally .

Actually one thing thats made the Americans sit up and take notice is the regulating bodies in states like Callifornia making the standard flex fuel blend E51 I think due to vapour pressure reasons . Do a search on that one . It probably doesn't work out too bad provided the other 49% is something better than cats piss .

Somewhere in one of those American threads someone quoted that a lower ethanol blend was getting them less range than ULP but more economical running from a cost point . It may have been ~ E30 , can't remember .

Anyway I'll run this E50 through and then brew up a tank of HippE40 and see what happens . I'd rather be doing this with United E85 than EFlex E70 because less of it is the whatever but there's only EFlex close to here . If someone here can tell me where to buy fuel grade E100 in Sydney for reasonable money I'd try that .

Cheers A .

[STATUS]

we do quite alot of 50/50 tuning and the results are great but customers ALWAYS end up at full strength e85 after a few months as they CBF'd mixing.

[discopotato03]

I'd like to see some comparitive results of E50 vs E85 if you have them Trent . What sort of difference are you finding power and ignition timing wise ? I don't suppose you've blended anything lower like say E40 ?

For me I can be bothered and because I'm no stranger to fuel containers its not really any extra effort . Fuel prices piss me off no end and range is important - to me .

I'm also interested to see what you think of the E50 for round town type driving .

Thanks , A .

Edited November 12, 2012 by discopotato03

[Manuel Kasko]

Keen on this info as well

[SimonR32]

we do quite alot of 50/50 tuning and the results are great but customers ALWAYS end up at full strength e85 after a few months as they CBF'd mixing.

Too right!

Green car ran a 50/50 but it's more lazyness than anything causing me to go full E85 with the GTR