badinfluence

OK, I am going to try this out and home I don't get.... FLAME ON......to late.....


As some people know E85 is a high ethanol based gas mix. Contrary to popular belief nothing regulates it to be 85% ethanol, other than it cannot EXCEED 85%. I can range from 50-92% based on studies and the seasonal "blend."

Premixing has been proven to lubricate Apex seals and assist Gasoline's lubrication while it burns

Gasoline burns slower than Ethanol, takes less heat, but has more energy per liter.
Ethanol, takes more heat with it by burning faster, but has less energy so more is needed.

E85 at 60% is corrosive to most fuel pumps without the proper Viton seals.


All that on the Table, I have a some questions to ask.

98RON or 93 Octane Gasoline such as Shell V-Power is 15% Ethanol or around that with additives and such. If you add 8oz of your favorite premix to the 16gallons in the tank:

How does that effect the Octane Number?
Does it Increase the chance of Detonation (By costing you octane)?
Does it Decrease the chance of Detonation (Secondary by cooling)?
Does it Increase the total energy extracted per liter of gasoline (by slowing the reaction down and providing a secondary fuel:oil)


If you did premix with E85 that is about 55% Ethanol (winter blend), would that be enough to properly lubricate the Apex seals and counter detonation with High Intake Temperatures. (100F+)?

This was to big of a question for the Newbie Thread so I didn't want to add to the pool of questions there.

My theories are the Premix costs you about 3 octane...but, lubricates and prevents detonation by altering the flammable properties of the mix, passively cooling and lubricating more like super lubricated gasoline, acting like 100 octane(by preventing detonation). The slower burn cannot be detected by the ECU, but doesn't really harm the engine and in most ways helps.

My Second Theory is that if you multiplied your premix amount by 125% you could use E85 on the RX8 without destroying seals or reducing the life via lubrication of your engine, while getting all the effects of high octane cooling.


Alright....FLAME ON.

ken-x8

I assume that all of your questions apply after you've changed your injectors to flow rates appropriate for E85. And maybe increasing the fuel pump's capacity?

Ken

badinfluence

Aren't the Series II injectors updated from the Series I?

But yes, all this was ideal world scenario.

poacherinthezoo

I believe the S1 cars have 2 primary's (290 cc) and 1 secondary (380 cc) injectors per rotor. Series 2 cars use a single primary (405 cc) and a single secondary (500 cc) per rotor. But I would need to double check the parts #'s to be sure.


You lost me with the octane drop due to premixing. Care to elaborate on how 8 oz of premix + 16 gallons of fuel (2048 oz) effectively decreases the octane rating by 3? I think I'm over simplifying my calculations and hence not getting the same numbers as you.

I ran across this not too long ago with regards to running E85 in the RX8: Esmeril Racing - Products
It seems to support your theory, but in full disclosure, I can't comment on the credibility of the information. I just came across it a few days ago and this thread prompted me to search my browser history for it.

jasonrxeight

there is no way 8oz is gonna drop octane of 16 gal gas by 3.

badinfluence

Hey that is one question answered...

Do you think it even drops a point?

badinfluence

I forgot to mention something earlier. I was thinking Premix + OMP system would drop it 3 points. Not just the Premix by itself I didn't think of that till just now. Flat out guessing man, no maths used on that one. I had no idea where to start. The only thing I have heard is that if you have to much oil in a piston engine, it can mess with the spark.

BTW thanks for the link, that was very useful. My biggest worry is what people say "change your fuel pump" because of the fear that the pump is used and just won't take it instead of assuming it is a good pump running at factory spec. Error on the side of caution is absolutely the right measure on the internet, but that was the worry. AEM makes a E100/E85 special ITFP that was looking at if I made the switch, but right now it is more of a Q&A for research I am doing into Forced Induction on the RX8 platform.

Instead of H/W like the tread says, I am doing like a whole semester on pros/cons.

jasonrxeight

probably not even 0.1 point. totally negligible.

jasonrxeight

what are you trying to do exactly?

badinfluence

Mostly trying to learn more about the interworkings of the rotary. I really like the concept of the engine and driving it, but I love problem solving. I am trying to just know the platform in and out and see if I can improve some things. I am not looking to move mountains or even make power, just learn overall.

E85 is something that seems like a good fit for a heatsoaked engine. Ethanol is pretty good at getting the heat out fast, but not great as an energy. I was wondering if you found a way to use E85 and hybrid gas to make the car run longer in like an endurance race.

I am wanting to do SPEC FB RX7 at some point, so I wanted to see how the 8 reacted before I went way lower tech with the FB. I know the engines aren't even in the realm of the same, but I am trying to learn the rotary in general, not just the RX series.