How high of a Dynamic Compression Ratio can you run with E85? It's 110 octane. 85% Ethanol 15% Gasoline.

I believe that this may be an easier solution to increasing power in a "street" vehicle than Methanol or straight Ethanol.

I know that LameRandomName and a few others have been looking into this also.

 

Great question.
Not sure if it applies to you but I thought I'd throw this link in there for others to look over.

I'm starting to come around to E85...in the beginning there was little or no true scientific examples of its performance but I'm starting to read more and more that are based off of science and not lobbiest mumbo jumbo.

Edit: LOL....I just noticed that I never put the link in the post. Only took 2 days to notice it....Now I can't find the dang page...whatever. Sorry all.

 

I'm kinda wanting to throw some high flow heads that have tiny chambers on a small motor and use a tiny camshaft to keep the factory PCM. I could either go with less aggressive lobes that have long seat duration, but they don't have the lift that I'm wanting to use. I could spread the lobes out a BUNCH, but that would hurt overall torque (though it would keep it very docile.) Or I could use longer duration lobes, but that would move my RPM range above the PCM capabilities.

I know that converting the fuel system to be E85 compliant may be a PITA, but in the long run, I think it'll be worth it.

 

E85 works good with boosted setups, very good... i have a vid on my laptop of a turbocharged 5.0 mustang (95 with a 331 R-block stroker) making a little over 1000rwhp with only E85 fuel in the tank (no race gas, nitrous, etc). Some others over on svtperformance are making in excess of 800rwhp with it on high boost too. So it should work excellent with any DCR you can feasibly throw at it in a NA street car, IMO.

 

Don't ever spread out the lobes a bunch just so you can use short duration aggressive lobes. #1 should be the valve control, #2 should be the power curve and then worry about the DCR. The DCR is a concern but in some setups more DCR doesn't make the most average power.

Bret

 

Maybe a better question might be to ask would be, how much does increasing your octane allow you to increase DCR? 104 Unleaded, 110 Unleaded, etc. E85, Methanol, etc.

 

The thing that also needs to be remebered is QUANITY you need to burn a hell of a lot to make power. Yes the octane will allow you to run higher compression but that still does not make up for the fact it contains less energy. That is what could make it still suck for a street car might as well run race gas but the time you pay for the increased volume you need to burn to amke more power.

 

Getting E85 is no problem for me. There is a pump for it 4.6 miles from my apartment and 1.3 miles from my work. The price is competitive with other pump gas.

I know it takes roughly double the quantity for alcohol to equal gasoline, but I don't know what the difference is for E85.

I have been reading that Flex Fuel Vehicles that run on both Gas and E85 get 5-15% poorer fuel economy. However, those engines are handicapped so that they can run on either, but are not optimised to run on either also. I betcha that an E85 optimised engine would be able to get the same fuel economy as a 93 octane gasoline only engine while making much better power through the RPM range. It will definitely require higher flow fuel system, stronger ignition system, and a few other differences, but don't all "race motors"?

Imagine running 13.5:1 static compression with a small cam with no problems on the street. Maybe 15:1 or higher with something sized around a CC306. Or a forced induction application with higher than 11:1 and no intercooler.

 

Chestion, as with any alky you need to burn more of it in any situation. Your MPG will go down but you can make more power with it.

Bret

 

I know that Bret, but I don't want to rattle the engine by going too far.

The E85 station is just a minute off my route to/from work so I checked the price last night. At just over $2/gallon, it is right in line with the 87 octane everywhere else. So even if I do need to use double the volume, that will be cost effective over 110 Unleaded @ around $5/gallon.

 

Hey! No fair stealing my idea before I can get all the parts together!

BTW, I believe that E85 is only 105 octane. I wouldn't swear to it because I am not positive, merely pretty sure.

 

I'm finding that people are quoting 96-115 octane. I wonder why the range is so wide? I guess I could just go by that pump again and look closer to see what it says.

I'm actually trying to help you also

 

From the iowacorn.org (pro-ethanol) website:
You also need to keep in mind that for high performance uses, you need to know the "motor" octane. What is posted above is the typical (research + motor)/2 octane number that you see on the local gas pump.

 

anyone know what air fuel ratio you would want to shoot for?

 

Fuel injectors should be sized for approx 20% more volume.

According to www.e85fuel.com its 105 octane and that's what we have up here. 1 station in a major metropolitan area and it sells for about the price of 87.

Keep in mind it is not 85% ethanol like you may think, the ethanol itseld is denatured 3-4% with gasoline so you can't drink it. The denatured ethanol then has the gasoline blended into it.

I'm excited by it.