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Ghosty
01-26-2008, 01:46 AM
I gotta tell yah, the more and more I hear about the benefits of E85, the more I stop paying attention to 3SGTE swaps and the more I start paying attention to ethanol conversion. No kidding.

It's pretty natural for me I guess-- living in the cornfed state of Illinois. It's not uncommon for E85 to be 20 percent cheaper than unleaded full-on-dino fuel in these parts. Besides the price, it increases engine life by dissolving any buildup in the fuel system and within the head, much like cleaning it with a cotton swab drenched in alcohol (because it is, essentially, diluted moonshine).

On top of that, there's the complimentary octane rating of 105, which means I can run with all the benefits of a high-compression setup without having to resort to 92 octane. (as a side note, the octane rating varies with the mix of E85 on a seasonal cycle, and can go as low as E70 in the wintertime to improve cold start)

Yes, I know that your gas mileage drops, anywhere between 8 and 20 percent is normal depending on the success of the tune. But the pricepoint is still attractive and will continue to be attractive in these parts. I also know that it has the potential to corrode parts. But I've seen cars that have run on E85 for 5+ years with absolutely no issues.

Well ok, there is some wear -- one user I read of sent his Walbro fuel pump in after 3 years of E85 use to be broken apart and examined. The technician was astonished to find slight wear, which he compared to effects of living in coastal areas with salty air (though the wear was less than that comparison). There's also been some issues with cars equipped with aluminum fuel rails, mostly Hondas. Apparently E85 corrodes aluminum enough to the point where aluminum residue builds up in injectors and on spark plugs. But I'm pretty sure my 4AFE doesn't have an aluminum fuel rail.

Alright, enough about that. My real question is about the compression to shoot for in the 4AFE. E85 may be plentiful in my parts, but if I ever take the Celica on a road trip, I might need to make do with 92 octane. So I can't go with too extreme with the compression.

What I would like to do is put in some pistons that, while might be cutting it close to detonation on stock timing on 92 octane, would work if timing was retarded to some extent. Then, when on full E85, crank up the timing as necessary.

I'm probably going to have to crack open an engineering text to get some really precise answers, but I've heard 11.5:1 is not unheard of on 92. What are your thoughts on this? Any reading materials you could suggest I take a look at?

KoreanJoey
01-26-2008, 08:19 AM
Water injection would be a good safeguard for 11.5. That and maybe even some retard. Anything to get the cylinder temps down is a good idea.

MrWOT
01-26-2008, 08:28 AM
Custom pistons and headwork and it can be done

Ghosty
01-26-2008, 07:20 PM
Water injection would be a good safeguard for 11.5. That and maybe even some retard. Anything to get the cylinder temps down is a good idea.

Yeah I was hoping to get the compression as up as high as safely possible for a street tune... to retard the timing is a must.

As far as water injection -- I'm sure it works and works well, but I really don't want to rely on a system like that for street use. If I were to damage it when I installed it, miscalibrate it, or if it were to fail suddenly on a road trip, I'd be screwed. In many cases water injection would be ideal though.

Come to think of it... maybe I should just shoot for a safe 92 octane compression with standard timing, and then just crank up the timing for the E85. This talk has me concerned about cylinder temps and that doesn't seem like a safe thing to push for a DD car/ road trip car in the summertime.

evolution
01-26-2008, 07:34 PM
keep in mind, that even though e85 is %20 cheaper for you, it has less energy per gallon, which translates into worse fuel economy. If you're looking to save gas money- this isn't the fuel for you (at least not now)

tuner4life
01-26-2008, 08:18 PM
^Yeah, you save $ per gallon, but my G/F's dad has a caravan that you can run e-85 in and he says that the mileage goes down enough that it isnt worth the money to put e-85 in. It actually ended up costing him more per mile than with reg. pump gas.

Ghosty
01-26-2008, 09:12 PM
keep in mind, that even though e85 is %20 cheaper for you, it has less energy per gallon, which translates into worse fuel economy. If you're looking to save gas money- this isn't the fuel for you (at least not now)

E85 has less thermal energy than gasoline on a molecule-by-molecule basis, that's true. Just looking at thermal energy, you get 19,000 BTUs for every pound of gasoline at the AFR for maximum power (12.5:1) -- compared to 13,400 BTUs per pound of E85 at its AFR for maximum power (6.975:1).

However, if you look at specific energy, E85 makes anywhere between 5 and 30 percent more power than gasoline, depending on how much air you introduce into the system. For example, consuming 100lbs of air in the system will yield 27 percent more thermal energy on E85 compared to gasoline (152,000 BTU on gas and 193,000 BTU on E85).

It's kind of hard to demonstrate what these calculations actually mean, but the first calculation looks at the energy stored in the C-H bonds of each fuel, and the last calculation looks at how efficiently the fuels actually burn. What it shows is that E85 is a more efficient fuel because it produces more useful work.

(A person who did a E85 conversion on a WRX did the research and calculations, so the credit goes to him http://forums.nasioc.com/forums/showthread.php?t=803341)

The practical result is with just a minimum of modification, you'll get about a 5 percent boost in horsepower and torque. For engines modified with high compression/ increased boost pressure and a finely-tuned engine management package, there'll be more like a 30 percent boost in power. Again, this is because it burns more efficiently.

But yes, the mileage decreases. Even on a properly tuned car, there will be approximately 20 percent hit on mileage. And the reason why this is: more than the energy content, the actual AFR is "richer." Above you see the stoichiometric AFR for maximum power in E85 is 6.9 compared to gasoline's 12.5. So, you burn more E85 in a cycle than gasoline to get a full combustion.

So to break even, the price of E85 must be 20 percent lower than 87 octane gasoline. In Illinois, it's a break-even proposition for the time being, but the Illinois EPA offers rebates for vehicle conversions as well as a $300 refund on E85 for three full years after the conversion. So that helps. And as time goes on, especially with pressure from Chevrolet, GM and soon to be Toyota, who have already or will soon produce flex-fuel vehicles, and factoring in advancements in E85 production as well as oil scarcity, the price of E85 will continue to drop. For the time being, it's an investment, but the payoff is in the not-too-distant future.

And also - the current flex-fuel vehicles suck, in my humble opinion. I'm not at all surprised Tuner's G/F's dad had to pay more for fueling up with E85. The reason is the current generations are designed around 87 octane with E85 as an afterthought. The more cost-effective option is an high compression/ turbocharged engine designed to E85 specs that can retard timing/ lower boost to accommodate 92 octane on a rare occasion.

Cliff notes: E85 burns more efficiently and offers more power, at a cost of reduced gas mileage. It's only cost effective to run E85 on a high-compression/ boosted setup. E85 will be much cheaper in the near future and will be a better alternative. The current line of FFV are a lazy attempt at capitalizing on high gas prices.

VikingJZ
01-28-2008, 06:08 AM
Ethanol, in my opinion, is a marketing ploy.

I'm still waiting for cars to be efficient on corn oil or something like that.

Hell, if I got 12MPG and could throw a mixture of canola and alcohol in my car reliably, I'd do it.

KoreanJoey
01-28-2008, 06:27 AM
Ethanol, in my opinion, is a marketing ploy.

I'm still waiting for cars to be efficient on corn oil or something like that.

Hell, if I got 12MPG and could throw a mixture of canola and alcohol in my car reliably, I'd do it.

Biodiesel sounds like it's for you... we have a guy come every couple of weeks and take our deep fryer oil, which he turns to biodiesel. Beats paying to get rid of the nastiness.

VikingJZ
01-28-2008, 06:29 AM
I have thought of doing so, but I don't want to mess up a nice car like my Lexus. I don't mean that in an arrogant way or anything, but If I did this It would to a car like a Corolla or Tercel. Something light, FWD, automatic, and very cheap and easy to work on.

MrWOT
01-28-2008, 09:06 AM
I was pissed as all hell when prop 87 got shot down in CA, going to delay us getting e85 for a long time. All because people watch the bullshit commercials and don't read the fucking bills :madfawk: If I had access to that kind of fuel I'd have a field day, but nooooo. Lazy asshats who watch too much tv have to ruin it for me :(

KoreanJoey
01-28-2008, 09:47 AM
That sucks... I don't think I've seen any E85 stations up here even...

bloodMoney
01-28-2008, 06:12 PM
You can find any local e85 stations here (http://www.e85refueling.com/) there were two about 10 minutes from where I live and I didn't even know it.

I would suggest replacing your fuel lines before doing the conversion. If they are rusty at all, the ethanol will eat up the lines. I happened to me when I tried putting e85 into my 91 crown vic. In three weeks, my feed line popped. two weeks after that, my return line popped. After that I just stopped using it...

The thought of rust in my dd's cylinders scared me...

~bloodMoney

Ghosty
01-29-2008, 01:59 AM
I was pissed as all hell when prop 87 got shot down in CA, going to delay us getting e85 for a long time. All because people watch the bullshit commercials and don't read the fucking bills :madfawk: If I had access to that kind of fuel I'd have a field day, but nooooo. Lazy asshats who watch too much tv have to ruin it for me :(

What's prop 87 and what were they saying about it on TV?

evolution
01-29-2008, 02:05 AM
http://www.smartvoter.org/2006/11/07/ca/state/prop/87/

Ghosty
01-29-2008, 06:15 AM
http://www.smartvoter.org/2006/11/07/ca/state/prop/87/

That's some kind of proposition! I like the idea -- unfortunately too many people saw it as a threat to increased gas prices, from what I see.

That's so narrow-minded of them. Sure, you'd take a little hit at the pump for a little while. But then an entire self-serving system would kick in and the prices would drop like a rock.

I say this because first you take a hit in gas prices, consumers thing "wow, this gas is really fucking expensive! I should start buying cheaper E85..." And by then, the tax money from that would have been funneled to produce REALLY CHEAP E85.

So you have people that won't buy the even higher priced gas, but the alternative is much more attractive. You also have to consider how money is then diverted away from oil-rich countries, and right back to farmers in the USA. And that money cycles around the economy, instead of contributing to a massive trade deficit.

Perhaps the biggest flaw I see, though, is the dearth of qualified E85 vehicles. I've said before that current FFVs suck balls. First, I say, give an incentive for people to buy or companies to make E85-optimized vehicles (big difference).




I would suggest replacing your fuel lines before doing the conversion. If they are rusty at all, the ethanol will eat up the lines. I happened to me when I tried putting e85 into my 91 crown vic. In three weeks, my feed line popped. two weeks after that, my return line popped. After that I just stopped using it...


Replacing the lines is recommended. Strictly speaking, most people shouldn't have problems with fuel pumps/ regulators/ lines / rails in their stock car. This is because most cars produced after the 90s were at least E20 (20 percent ethanol) compliant. But yes, if you're doing a conversion, you should do it right and get compatible fuel lines.

You should also plan on replacing the fuel filter some 500 miles after the conversion, as alcohol cleans like a mother and will clog it fairly efficiently.



I have thought of doing so, but I don't want to mess up a nice car like my Lexus. I don't mean that in an arrogant way or anything, but If I did this It would to a car like a Corolla or Tercel. Something light, FWD, automatic, and very cheap and easy to work on.


I wouldn't do this to your SC either. Love your SC, by the way.

I doubt the long-term viability of converting a conventional gasoline car to E85. We all know the rule of thumb for taking an engine out of original parameters -- it'll probably fail sooner.

Still, if it will save me a few bucks, I'll give it a shot.

MrWOT
01-29-2008, 07:43 AM
Yeah, the commercials were pretty much all "Vote NO on prop 87 to keep gas prices down or else gasoline will be FIVE DOLLAR A GALLON!" and in the small print at the bottom, sponsored by chevron/texaco. :rolleyes:

Would have gone up maybe ten cents for a few months, then the competition from the e85 stations would have forced a price drop. But noone cares to look anymore, I'm fucking ashamed of my generation politically :(

grayscale
01-29-2008, 10:42 AM
Ethanol, in my opinion, is a marketing ploy.
That's funny cause there is already a good bit of ethanol in regular pump gas as it is.


I have thought of doing so, but I don't want to mess up a nice car like my Lexus. I don't mean that in an arrogant way or anything, but If I did this It would to a car like a Corolla or Tercel. Something light, FWD, automatic, and very cheap and easy to work on.
Problem is you have to have a diesel engine to use biodiesel.


I'm probably going to have to crack open an engineering text to get some really precise answers, but I've heard 11.5:1 is not unheard of on 92. What are your thoughts on this? Any reading materials you could suggest I take a look at?
This would be a good time to read that Modern Engine Tuning book you downloaded. There is a perfect chapter on fuels and compression ratios. He explains gas ratings and shows some very interesting tests on comp ratios. 11.5:1 on 92 would be nearly impossible without either a lead additive, concentrated octane booster or avgas mix. He also explains very well why it's not as easy as just changing your timing. Interesting stuff, I just read that chapter last night!
I'm gonna have to read up on this E85 a bit more though.

What's that other fuel blend being found in major metro areas these days, k-something?

KoreanJoey
01-29-2008, 10:52 AM
Mtbe?

grayscale
01-29-2008, 11:00 AM
Mtbe?
Whosawhatsit?

KoreanJoey
01-29-2008, 11:02 AM
go look it up noob.

grayscale
01-29-2008, 11:06 AM
Okay, googled, so what about it? Is it available for public consumption?

KoreanJoey
01-29-2008, 11:09 AM
Oh sorry... thought you were asking about fuel additives...

Other than Biodiesel I have no idea.

grayscale
01-29-2008, 11:12 AM
Oh, ok. Yeah, the k stuff is available at pumps, saw a spot about on tv but don't recall much, just that it was a higher ethanol blend.
About the mtbe though, where can you get it?

KoreanJoey
01-29-2008, 11:15 AM
Never heard of anything but E85...

Ghosty
01-30-2008, 06:38 AM
This would be a good time to read that Modern Engine Tuning book you downloaded. There is a perfect chapter on fuels and compression ratios. He explains gas ratings and shows some very interesting tests on comp ratios. 11.5:1 on 92 would be nearly impossible without either a lead additive, concentrated octane booster or avgas mix. He also explains very well why it's not as easy as just changing your timing. Interesting stuff, I just read that chapter last night!
I'm gonna have to read up on this E85 a bit more though.

What's that other fuel blend being found in major metro areas these days, k-something?

I recently finished downloading the book and took a quick read over some of the chapters. Found it to be a pretty good read, even if dated. There's even a old 4AGE he uses as a stock photograph, and he discusses it as an example for compression vs timing. Anyway, I looked at what he had to say about compression vs octane, and he had this nifty little table... (pardon the "html" alert)...



Bore diameter (mm) 91-92 octane 95-96 octane 98-100 octane
76 9.3:1 9.8:1 10.2:1
83 9.2.1 9.7:1 10.0:1
90 9.0:1 9.7:1 9.8:1
100 8.6:1 9.0:1 9.4:1

And a 4AFE has a bore of 81mm and a compression of 9.5:1 on 87 octane... which doesn't compute in his table, because 81mm would surely have knock at that octane and compression. The table suggests I would need somewhere between 92 and 95 octane to run that compression, and we well know that's not the case.

I wonder if engine technology has developed since this book in ways that allow for higher compression.

MrWOT
01-30-2008, 07:39 AM
Yeah it has, knowledge has anyway. Chamber/piston shape, and port geometry will let you do it on 91 octane if you have the money and know how to make it.

grayscale
01-30-2008, 11:10 AM
The last time the book was updated was 2002 I believe, so it's pretty up to date on most subjects it covers. As for your findings on his table-
The octane ratings shown are true ratings, not PON/pump numbers we see at the gas station.
The table is just a simple reference guide as he is generally speaking of all engine types. Paragraph just above the table starts off-
"As indicated earlier there are far too many factors involved to give an accurate answer, but the figures shown in Table 3.5 will give a guide to the compression ratio for naturally aspirated engines with a reasonably quick burn combustion chamber..."

Ghosty
01-31-2008, 03:26 AM
The last time the book was updated was 2002 I believe, so it's pretty up to date on most subjects it covers. As for your findings on his table-
The octane ratings shown are true ratings, not PON/pump numbers we see at the gas station.


Ooooh... ok... heh, that makes a bit of difference :D

An approximate RON for PON 92 is 96, with an error +/- 2.
Going off the charts, it looks like between 10.0:1 and 9.7:1 would be a good approximation. Considering the stock engine has about a 3.2% higher compression than the closest 83mm equivalence on the chart, probably because of piston design and a couple other factors, I think that 10.3:1 would not be out of bounds.

10.3:1 on pump gas- that sounds about right?

KoreanJoey
01-31-2008, 08:10 AM
No... Um... I can't remember what my Gen 3 is... But I though that the 4th Gen BEAMS motors had higher compression than that.

MrWOT
01-31-2008, 09:42 AM
You know, the 3S head has a LOT of room for improvement in this catagory, I've been studying chamber design and getting ready to cloverleaf my spare head, don't have the funds to get custom pistons though :(

grayscale
01-31-2008, 10:28 AM
Ooooh... ok... heh, that makes a bit of difference :D

An approximate RON for PON 92 is 96, with an error +/- 2...I think that 10.3:1 would not be out of bounds.

10.3:1 on pump gas- that sounds about right?
MON is the important one- (MON+RON)/2=PON- so you're MON for PON 92 is about 88. Just to be clear we're only speculating here, I agree 10.3-5:1 would be good for use with E85 and if standard fuel is used just add some octane booster.

Rix86
02-01-2008, 06:53 AM
Most all toyotas have aluminum fuel rails.