E85 Conversion
 

I was wonderign what a guy would have to do to convert his prised posession rotary engine to run on flex fuel.


If so .. how? cost? Who can do it?

I don't believe there is any kit to do this, but you would have to retune the EMU and probably add bigger injectors. Also, there may be parts of the fuel system that aren't chemically compatible with large amounts of ethanol. You do understand you'd get about 40-60% of the fuel economy you're currently getting, if you used E85?

i thought it was closer to a 20% loss of mileage...not 60-40:Eyecrazy:

60% would be pretty extreme, even though I put that out there. The rule of thumb (when running 100% alcohol) is you need about twice as much to go the same distance. When I run 10% ethanol mix I see about a 5% difference, so I figure you could easily see something in that range from E85. I do admit I could be wrong, but I've yet to see anyone convert an RX-8 to run E85 and give us hard data on power output, economy, etc.

you' need a whole new engine- since much of the area exposed to the fuel is aluminum and the e85 eats aluminum for breakfast- bye bye renesis.

In my part of the world, it's getting hard avoiding the 10% ethanal gasoline they are selling. Why do people think ethanol is such a good idea?

The ethanol is replacing MTBE as an additive for cleaner burning fuels. MTBE use in gasoline was banned by EPA due to groundwater contamination issues.

So bottom line, because oil companies can't keep their station tanks from leaking, we have to use a higher priced additive (ethanol) that gives poorer mileage and increasing their profits. Simple, eh?

That's too bad, I would love to see an RX8 with less than 10mpg highway :lol2:

On another note - is the 10% or so ethanol they have in most gasoline now actually dangerous for our engines? any way to counteract this?

Supposedly, the 10% maximum was set to protect all existing engines. As time goes on, newer engines may be able to handle higher percentages but the lag time for phasing in would have to consider the numbers of "older" engine vehicles still in use.

When EPA first mandated cleaner burning fuels and unleaded gasoline, ethanol was not considered due to the damage it could cause. Also, the current pipeline infrastructure can't be used to transport 100% ethanol because it would also damage the pipelines. So continuing the trend, higher priced trucking of ethanol to refineries drives the prices up or building new pipelines will do the same.

The reason for the lower mileage is that ethanol, when burned, produces less energy than gasoline with MTBE.

So no to E85. lets see option number 2 is ....


Hydrogen fuel cell? running off of duel fuels?

mazda already has rx-8 hydrogen burners running on the road. its pretty easy to convert for hydrogen actually.

http://www.fuelcelltoday.com/FuelCel...2,9540,00.html

http://www.autoblog.com/2006/02/15/m...rx-8-in-japan/

one fueled up at the hydro filling station in norway

http://rotarynews.com/node/view/810

^ In '93 they "Developed test version of MX-5 equipped with hydrogen rotary engine"

!!!

Three reasons:

1. Reduces dependence on petroleum, which is getting scarcer and is usually imported.

2. Enriches local farmers (actually agribusinesses), since it's made from domestic crops.

3. Since it uses crops that would otherwise be surplus low-cost food, it starves out third world populations.

Not everyone likes all three reasons.

Ken

You forgot that it takes a lot more energy to create in the first place, is more expensive then gasoline (even at todays prices), actually slightly worse for the environment, and even if we covered every square inch of the planet with corn to make the stuff, we wouldn't have nearly enough.

So really, it's obvious why politicians are pushing it so hard. It's evil.

However, it makes the fuel burn hotter and more completely, cutting down on CO emissions while raising Nitrous Oxide (greenhouse gas) emissions.

You can add a cat that will burn the NO but it adds about $1k to the cost of the car and I assume has the same power loss issues associated with a regular cat.

Now if only we could figure out a way for produce N2O this way... then people might not mind recirculating exhaust gas :lol2:

Why would anyone want E85. It provides about 70% the energy content of gas, that translates into 70% the power and 70% the fuel economy yet is more then 70% the cost of gas. E85 is a poor fuel when all the energy it takes to grow and process are taken into account not to mention the amount of water needed for processing. The only way alcohol will make senses is if they can make it from waste products of plants which is still a developing technology.

I think it would be a great idea.

Gasoline engines are not efficient anyways, I think they only have around 30% efficiency. That is where we need to focus.

As far as E85, I would be happy running %100 alcohol. Forgranted it does not provide as much energy, but Im sure with technology (look at the Renesis) progress could be made very quickly.

The process of making the fuel is much much cleaner than that of gasoline or oil. Essentially it is the same process as making beer, so much of the biproduct is steam which is very safe for the environment.

Look at Brazil, the price they pay per gallon of Ethanol is about $1.00. Sorry I would much rather pay $1.00, have less MPG, higher octane, and get away from the nations that sell crude oil to finance anti-western groups.

Alcohol is not going to hurt your engine. It is not going to eat any parts inside the engine as nothing inside the engine is aluminum. The rotor housings are but their wear surface is a machined sheet metal insert and it's coated anyways. Even if it was aluminum, you'd still be OK. There are lots of people that have made their rotaries run on various alcohols. You "may" and I'm not even sure this still applies, have issues with O-rings swelling. I've seen this on older rotaries but that was only with Methanol and not Ethanol. I'm not sure what the differences are with the Renesis but with much of our fuel today containing at least some Ethanol, I'd be shocked if they hadn't anticipated this.

The main thing you'll need is a way to reprogram the ecu. Luckily a wideband O2 sensor reads in lambda so it doesn't know what fuel you are using. This makes tuning easier as all you need to do is figure out what target a/f ratio you need to aim for and just richen it up across the board. You should be able to run more timing too but there are always exceptions and I'm not getting into all of that here. Basically just find a way to retune for it.

With the price of gasoline where it is today that would be just fine with me. If I got half the mileage but paid less than half as much for a gallon, it more than offsets. However leave it to our government to make things expensive. Alcohol gets taxed and tarriffed to death here so the cost advantage goes away really fast.

there is a hydrogen refueling site in plainview, ny

But is the $1.00/gal ethanol subsidized? If so, you end up paying more than what you do at the pump. It could still be cheaper, but without all the facts it's useless to assume anything.

Brazilian Ethanol
 

Brazilian Ethanol is around $.85 per Litre which is about $3.06 per US gallon. There are no longer any government subsidies to Alcohol (Ethanol). In fact there are huge taxes of almost 70% by the time the consumer gets the product!

The major difference though is that Ethanol there is produced from sugar rish SUGAR CANE and not from Corn. Using corn was the USA's decision to please the corn belt producers and make the Mexicans mad since this drove up the price of corn which is a stable part of their diet in tortillas and etc..

Ethanol can make sense if made from the right materials and for the right reasons - but using it to get elected (i.e. making yourself seem eco friendly and making the corn producers happy) is counter productive...

is about 100-105 octane versus premium at 91-93. might see better performance as far as gas goes if there is a way to convert it...

Oh give me a break! It's much simpler than that. We grow lots of corn. We don't grow much sugarcane. Use what you've got.

How about converting the Renesis to run on natural gas? There are quite a lot of cars in Europe that are able to run either on gasoline or natural gas with a flick of a switch, would that be feasible (or does it make sense) to do that with the rotary?

Ethanol is VERY hard on oil films.

As we all know, the rotary needs combustion chamber oil films from the OMP injection (and premix if you do this) to reduce seal wear.

Just the 10% ethanol ratio used by some localities for fuel emissions will have some effect on the oil film in the combustion chamber (that is why most localities do not mandate over 10% as it gets really bad then), but it is really not good for the rotary since we need the little OMP oil we have left alone. If you have to run 10% ethanol fuel because your locality requires it, I would premix in some fashion since we cannot control OMP rates.

E85, an 85% ethanol content fuel would require significantly more OMP injection rates, likely so much that it would be very hard to emission certify the engine, that this fuel makes no sense for the rotary. Other fuels, like hydrogen, have big possibilities.

I think ethanol would be a good move when they can distill it from lawn clippings and other high cellulose vegetation. From corn it is a loser and a ecological problem.

E85 is under $1.00/gallon at the pump

Think of the poor mileage threads that would come with E85, oh the horror of it all! "How many miles do you get before the light???" "I stop for E85 every day!!!"
;0

Ethanol is bad.
It's worse for the environment (its carbon neutral but has other nasty stuff in it).
Its more expensive to create, and all that corn we could use to feed starving people in Africa, gets poured directly into some fat asses SUV, and drives the price of food up.

Propane or hydrogen is probably the best alternative fuel for a rotary. You're going to want forced induction on either of those to make lots of power though.

Try driving cross-country when you have to stop for gas every 2 hours...

i love this idea! refill at home:)

The pump price has very little to do with the cost of production - more to do with the 'optics' of the green movement......

S

Regardless, if it's 1/3 the cost of premium you're still coming out ahead at 1/2 the mileage plus there's much greater performance potential for FI

E85 could be a good thing for a rotary. The operatve word is COULD.

First regarding corrosion;
Ethanol has no corrosive properties to aluminum. Ethanol likes to absorb water and after it reaches about 2% water it begins to become an electrolyte. In an aluminum carb that has brass jets ethanol methanol, isopropyl etc that has absorbed 2% or more water turns the carb into a battery and at that point it is corrosive. Fortunately modern automobiles including the RX8 won't suffer from that.

Ethanol like most alcohols (and MBTE) does accelerate aging on some lower density plastics. Not to an appreciable amount on higher density stuff like found in most of the fuel system - except the hoses.

Octane is between 100-105, and under evaporation (vaporization) cools much more then gas alone. So not only does it need recalibrating the mixture, timing can be advanced a bunch.

You can still run the motor leaner and put more heat in the combustion chamber rather then the exhaust. On a piston motor it will consume 15-20% more. Then again a piston motor only runs about 1200° EGT where a rotary runs about 1500° as it has so much detonation it has to be timed late.

Larger injectors and a good piggyback ECU would be required. While E85 has less BTU's per gallon the extra advance allows increased efficiency.

The only real drawback is E85 isn't quite as good of a lubricant as gas is.

E85 is a great gas, surprised all the negative posts here. it is a 105 octane gas (it actually acts higher than that due to its cooling evaporation). last time I checked, 100 octane race gas is $7 per gallon, and E85 is higher octane that 100 octane gas. E85 is all the rage in turbo/supercharge world.

Think about it. you can run a smaller engine at higher boost with E85, get you same power as if you were running big gas engine on 91 octane. so your mileage actually improves (give same power level). generally, if 91 octane gas lets you run 10 psi, you can run 20 psi on E85. imagine that.

only negative I can think of is that it isn't available everywhere, or I would convert in a heartbeat.

Your mileage will not increase on Ethanol. With a stoic air fuel ratio of close to 9:1 as opposed to 14.7:1, it'll never get close.

with E85, you can make same power with a smaller engine, so you mileage is no worse.

example:
turbo 2.0L engine making 200HP at 10psi running 91 octane gas
turbo 1.4L engine making 200HP at 18psi running 105 octane E85

according to Bell's turbocharger book, general rule of thumb is for every 3 octane, you can add 2 psi.

they both make same power (actually 1.4L should make more power at 20psi), so even with lower stoic air/fuel ratio, you should not get any lower mileage.

turbo car tuner can get about 25%-30% more power out of E85. but you use more fuel with E85. so in the end, they about cancels out.

it is not fair to compare E85 mileage on regular cars, because they are not taking advantage of its 105 octane. and for turbo car that does take advantage of octane, it is making so much more power than regular 91 octane gas. so it is not fair to compare mileage on an E85 engine that is making so much more power than regular gas engine.

Power does not equal mileage.

umm ... the US is the largest sugar cane grower in the world. also we grow more rice than corn in this country now. ahhaha

The battle for corn -> ethanol is really a step to eliminate farm substities that cost the taxpayers billions of dollars every year. the obvious choice would be to use sugar cane, radishes, potatoes, or any other veggie with a high sugar content.

i also loved the natural gas Idea! I contacted a guy who works with natural gas hondas to see if he had any ideas.


an oem supercharged natural gas powered hybrid rx8 .... a dream...

Ethanol
 

well I'm from Brazil and 40% of the cars run on ethanol!! the conversion is possible but requires mods to the seals , injectors and ecu reprog. everything should be fine but I don't believe you will be able to find a kit for the rx8 for conversion. the power will increase at least 10 to 20 hp just by using ethanol
and about miliage is about 15 to 20% less on a full tank!!!(much cheaper )

i wish there was a hydrogen refueling station in maryland. i'd look into getting the dual fuel system.

107 flywheel hp is kind of lame though. what is that... 12 second 0-60?

It's probably closer to a 60 second 0-12!

Give the man a cigar!

e85 at the pump does not eat aluminum at an accelerated rate like most ppl think..... there are many domestic vehicles that have aluminum engines that are flex fuel. not problems yet

the only things really needed to convert to use e85 is changing the rubber fuel lines to resist ethanol breakdown, fuel pump and filters, injector o-rings and grommets and a way to control the new fuel map.

it is also safe to put in a few gallons of e85 an mix with regular gasoline

You make it sound easy. To this day the RX-8 ECU is still a mystery to most. The fuel pump & filter is one plastic unit inside the fuel tank so that will require a new design. Also how many back yard mechanics feel confidant enough to replace their fuel system from the pump to the injectors ( I assume injectors also since E85 requires more fuel to make the same power as gas). Adding together all the parts, ECU work and labor how many decades will you have to keep the car to break even?

to clarify myself....

its easy to change out parts (IF you're mechanically inclined), and if you're careful around the fuel system, its not any harder. (just have an extinguisher nearby)

it will be hard to make it work for a car that it was not designed to use off the lot.

decades to break even? the made me lol.....

i do agree with you tho.

as with the ECU, it controls pretty much everything on the car so i wouldnt even mod this car if i had one.

changing all those parts would require 2 screwdrivers, a 10mm, 12mm, 8mm, 13mm, and maybee a pair of pliers. and about 3 hours ........ longer with beer/ smoking breaks.

E-85 homework..
 

Folks
I'm no expert, but there is quite a lot on the web re: E-85. http://www.e85viper.com/ is an interesting article to start with. Methanol is bad for engines because it eats away rubber, etc, Ethanol is not the same. The 105 octane rating and its larger physical volume makes up for some of the lower energy content. See article in this month's Mopar mag or Jan 08 Hot Rod. I think the folks that have pointed out potential need for larger fuel injectors are on target. Subaru WRX drivers are very into E85.. Or check out this article on autobloggreen.com http://www.autobloggreen.com/2007/08...y-car-use-e85/ I do wonder about harder cold weather starting, we already have some potential problems there. I'm seriously thinking of trying a gentle mixture of E-85 with 93 octane once the weather warms up here in the NE...