E85 Conversion
10-02-2007, 01:25 PM
#26
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?
10-02-2007, 02:03 PM
#27
Got Another 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.
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.
10-02-2007, 02:58 PM
#28
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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.
10-02-2007, 05:12 PM
#31
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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.
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.
10-07-2007, 07:20 PM
#36
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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.
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.
Last edited by kartweb; 10-07-2007 at 07:43 PM.
10-08-2007, 07:27 PM
#37
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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.
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.
10-09-2007, 12:41 PM
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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.
10-09-2007, 09:39 PM
#40
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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.
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.
11-06-2007, 01:35 AM
#41
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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...
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...
11-08-2007, 03:45 PM
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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 )
and about miliage is about 15 to 20% less on a full tank!!!(much cheaper )
11-12-2007, 06:43 PM
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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
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
11-12-2007, 06:59 PM
#47
He's as bad as Can
Last edited by expo1; 11-12-2007 at 07:03 PM.
11-12-2007, 09:22 PM
#48
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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?
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.
11-17-2007, 09:52 AM
#49
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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.
03-01-2008, 12:14 AM
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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...
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...