Peeps running e85 query about stronger blending over time.

Hi all,

I am about to switch to e85 blend to give the engine a bit more headroom with the corky turbo. I just had one scientific question in mind. I could be completely wrong with this, but hey it seemed like a good discussion.

Say I fill up the first time before my tune with lets say at 1/4 of a tank of P98 left....15L of e85 and completely fill the tank to the click with P98. I go for my tune on this mix, all is well. Less knock, more kw.

The next time I fill up again at the 1/4 mark, hell why not, let's fill again with 15L of e85 and completely fill with P98 (45L all up, including 1/4 already in there). However, this time my tank was not straight P98 as it was before the tune. It is now a blend of e85 and P98 in (0.25 : 0.75) ratio.

My levels of e85 are now higher and continually get higher over time if I fill from 1/4 empty as pump blend is now premixed. I call it "shit my cordial is now too strong" theory.

I did get advice to fill it with 12L of e85 and 28L of P98 to combat this on the continual 1/4 tank left fills after tune..

Does this make sense? Oh ...who cares just fill the ****ing thing already?

Sorry I never responded to your PM, been quite crook for a few days...

This is a bad idea, you need to keep it in "ratio"... On your first tune, you'll get e20, on your second, you get something like e23-24, maths is hard when sick, eventually you'll end up with close to e30, which I found out earlier this year can be enough to lean your car out 0.2-0.3 in terms of AFR, and throw your fuel trims off by quite a bit...

The leaning out is compensated for with the extra ethanol (octane/cooling) but you'll probably have a bit of a scare one day later on if you do a log, and your usual 11.8-11.6 AFR's are now 12.0 or leaner [emoji14]

Quote:

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Originally Posted by SarcasticOne

Sorry I never responded to your PM, been quite crook for a few days...

This is a bad idea, you need to keep it in "ratio"... On your first tune, you'll get e20, on your second, you get something like e23-24, maths is hard when sick, eventually you'll end up with close to e30, which I found out earlier this year can be enough to lean your car out 0.2-0.3 in terms of AFR, and throw your fuel trims off by quite a bit...

The leaning out is compensated for with the extra ethanol (octane/cooling) but you'll probably have a bit of a scare one day later on if you do a log, and your usual 11.8-11.6 AFR's are now 12.0 or leaner [emoji14]

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Thanks for the information mate, always helpful! So whats your fueling routine? I am just trying to find something I can stick to, or this will fall in a heap. Makes it easier my local united (5 mins drive) has a pump with all of their fuels in one hit, so no probs there.

I gotta go fill it up tomorrow for tune, looking to advance the timing and boost a little bit (nothing drastic). Perhaps net another 5-10kw if I am lucky, but more after the KR benefits with timing advance.

So just follow the 15L to fill on tune fill and then 12L to 28L from 1/4 tank then on? (30% e85 aka the 26% total eth mix).

I swear I am going to crack it and just use my 98 tune in a weeks time haha....

Hope your feeling better :)

Edit : I assume more e85 the better with timing change though, so always make sure the ratio favours eth if you happen to accidentally put more in.

Work out how approximately much I've used based on fuel gauge, work out what 25% of that is, add 1-2L, fill that much with e-flex...

Being slightly off is OK (tuned for e25 and running e22-28) but being anything more than 2-3% off either way is bad imo...

You won't go back to e85 once you've been tuned for it... Most likely you'll be pushing 250-260kw [emoji14]

Alcohol is addictive children.

Ok I will just follow the 1/4 full and 12L e85 and 28L P98 after my 15L tune fill ( or quick top up at any level - 6L : 14L). I will just have to show great disaprin lol

Now here is some interesting information to think over. Our Australian e85 is refined sorghum grain grain (sugar cane is a relative, not maize (corn). So the yanks are running the ultra viscous corn e85 as loving term (syrup), however we are running a higher refined grain based eth.

The US eth actually eats into their food production system, where as ours does not and is produced seperate (either from sugar cane waste or sorghum grain)

Could our eth be better for our fuel pumps due to its difference? Ethanol is ethanol which is the by product of refining both plants, but they are still very different fuels.

Thoughts?

I don't think there will be any difference at the pump - fermentation and distillation results in 95% purity, which is then further refined to make it blend with fuel - so there won't be much left other than pure eth.

The big differences are in the efficiency and simplicity of production. Sugarcane>eth is something like 5-7 times more efficient, meaning less plant matter needed (even though we don't eat the cane, it still takes up land, water, machinery etc which could otherwise be used for food, so it still effects food supply). From my understanding, it then actually less refining to get it into your tank (don't have to turn starch to sugar first) so we have a less refined product.
This is kind of interesting on the production side, comparing us to Brazil (who do it similarly to us apparently): http://large.stanford.edu/courses/2010/ph240/luk1/

I just know that cane fructose is FAR less viscious than corn fructose. The yanks kill themselves eating the shit. Our cane is far healthier. I can see this replicated in the refining process. Corn would have far sludgier byproduct than cane.

Corn doesn't have fructose. It has starch which can be converted to fructose by adding a bunch of stuff (this is similar to the first step of corn>eth production). Corn syrup that kills the yanks is just molten sugar and is neither fermented nor distilled.
For eth: once fermented (sticky sugar turned to alcohol) and distilled (evaporated and recondensed) to almost pure alcohol (somewhere between 95 and 100%) the difference in viscosity would be imperceivable (if present at all). The byproduct would be sludgy, yes, but that isn't what gets mixed with the petrol.
As far as i understand, distilled eth can't retain the viscosity of corn any more than vodka can retain the viscosity of a potato ha ha

Ahh ok, I assumed "high fructose corn syrup" was general fructose, which is an active ingredient in many of their foods. As they cannot grow sugar over there very easily, and they can corn, they use use the fructose from corn to suppliment as a sweetner. But hey, I could easily be wrong!

True about the fermentation, so what is the reason for the sticky pumps. What is the gum made of?

You aren't wrong. You are dead right, except that the fructose isn't naturally occurring but instead is CREATED FROM the naturally occurring starch in corn by adding enzymes and chemicals and science'n'stuff.

I'm actually not sure what causes the build up, but I don't think it's any different here from the US (my spill valve went AWOL on p100!). From some msf searching, it looked to me more about the eth-oil reaction, and they were finding that with dexos oil the problem was mostly (completely?) fixed. I'll have to do some more research though, as I want to go e85 as well :D

Is dexos oil the fuel additive? Id Like to know if Sam has inspected his injectors/hpfp to see if he has had any problems with e20 for a few years now... or if you were just unlucky!

I've got a bottle of the additive sitting in my garage, but it's cold, and I don't have a vice to do my hpfp [emoji14]

Also, CBF running e85 in winter and having to deal with cold start issues...

It would also seem that there's a new hpfp that is better with e85... I don't have the money to swap though :(

Quote:

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Originally Posted by SarcasticOne

I've got a bottle of the additive sitting in my garage, but it's cold, and I don't have a vice to do my hpfp [emoji14]

Also, CBF running e85 in winter and having to deal with cold start issues...

It would also seem that there's a new hpfp that is better with e85... I don't have the money to swap though :(

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I have had no cold start issues with my e85. What temps do you think give you the issues. Lowest since I have been on eth is about 3 degrees.

What hpfp are you talking about and where did you buy the additive from?

Full e85 has cold start issues...
E70 needs to be heated to 16.6C (61F) before it will combust... Petrol on the other hand is -43C [emoji14]

On MSF one of the guys running full e85 and meth had combustion issues when his boost temps dropped into the mid 50's F...

IE internals... Can find them via Google, got additive from eBay :)

Ahh makes sense then. You ment if you went full e85, I thought you meant your current e20 setup having cold start issues.

Oh yeah, I've heard of IE internals, but are they tested and proven? Autotechs are years old, so always wary of new products untested.

Its actually not the fuel pump that worries me, its the life of the injectors.

Anyone get squeeky noise on cold start on eth? I have been getting this since I have been running eth. Turn on car after sitting over night etc, 10 seconds later like a chirp and then gone. I don't really care, but apparently a spike in fuel pressure is causing it. I blame the eth!

Cold start squeaky squeak - Mazdaspeed Forums <- seems a fix with fuel tables, but doesn't seem to be detrimental and only in the cold.