1st, where are you buying E85? Not in the tampa area, so wtf are you trolling here for?

2nd, whats the dynamic compression of your car. As every study shows you need at least a 13:1 or better for ethanol usage.

Not to mention a tune for it, since the The stoichiometric value for gasoline engines is approx 14.7:1 air to fuel, whereas the "stic" for alcohol is around 9.x:1. Obviously, fuel tables for gasoline will not work when alcohol content is high.

 

ssshhhhhhh....
you're starting to sound like you know what you are talking about again...

 

1st point: I had a contract setup through one of our FSAE sponsors, Delta T since e85 is hard to find at the pump.

2nd point: you have your facts all wrong there. For e85 to be burned efficiently in a naturally aspirated engine, it should have 13.5:1 (or so) CR. That is also because of the octane rating of E85. The stuff you are buying at the pump isn't 93octan + ethanol. Is it 93 octane with the ethanol mixture taken into account

well, with e10 fuel having very little and very dissimilar properties to ethanol (as you gave the properties of) and the acts and performs and burns very similarly to "typical" gasoline (which stoich will usualy cary from 14.7-15.2:1); standard gasoline maps operate fine on it and don't have issues that can't be corrected for with the sensors in the system. As I stated, most OEM systems are capable of running and handling without an issue up to 30% ethanol mixture. The other nice thing that you don't know, as you must not have done your research or testing very well, is that ethanol actually likes running a bit lean

 

1. Cool, thanks for answering.

2. I never said it was, I know the octane rating is still true due to it being compensated for the ethanol in the fuel. I said 13:1 or better, 13.5:1 is better. You still didn't answer about the dynamic compression of your car.

3. Everything I've read says the stoich of E10 is closer to 13.8. And what sensors are you referring to? Seems like an awful lot of work for something that shows so little promise.

 

1: not a problem

2: sorry, the e85 was 11.5:1 with 19 psi and no intercooler. My car that I'm refferring to is 8.2:1 at 19psi and pretty much babied it around town...I'll say not frequently boosted.

3: you are spot on with the e10 I've seen reports saying 13.7-14.4...once again depends on ethanol batch and what form of gasoline...same reasons gasoline varies stoich.

 

so, homemade. What are the benefits, in your opinion, of running e10 without any motor modification, on an OBD1 car?

You get people like you that have done all this learning and building and what not saying how great it is. Then you've got things like my personal expierences. There is an apple and an orange difference between the way my car runs on e10 versus normal gas. I've got an old, higher mileage sohc 240sx that I drive daily. We've got an RX7 that shows an even more extreme adverse effects. (yes, i know they are different and therefore follow a slightly different set of rules, but those rules aren't that different. it still takes the same stuff to run, air, fuel, compression (which is 9.7:1 for an NA motor, so I'm not sure where the low compression comment came from....) , spark, all at the right time) In the newer cars, such as Rachel the truth's scion, the motor is noticeably less responsive when running E10, and it had no where near the miles my car does and it is OBD2. All of that, mixed with things like Mazda anouncing that rotory engines (1st gen rx7, 2nd gen rx7, and rx shouldn't run anything more than 10% ethanol due to an increased risk of engine problems. All of that mixed together seems to highly contradict how wonderful people on your side of the fence try to make it sound.

Edit: just to be clear, I'm talking strickly E10, not E85.

 

I really don't see any performance benefits...like I had said, it is wise chess game played by the oil companies and gov't alike. It was sold to be better on emissions, which it is, but at what trade off? I personally don't think it is worth it. I know many people who have ka24's and RX7's here (VA now) and no issues at all. I'd say its your car (check plugs and temps). Tune up time? My best friend had an 84 RX7 and never had an issue with it on e10. Yes, the cars will go down in performance, slightly on e10. My butt dyno didn't notice my 6 whp loss on the same tune (at the time the daily was only 218 on our shop mustang). Tuned up and couldn't get 1 hp back at the same boost.

Shit, my old beat as 1980 SR5 corolla doesn't have an issue with it.

I'm am curios as to what the fuel temps are getting up to down there? you guys still only in the 80's? temp has been one reason FL (and parts of texas) has waited so long to swap over.

I'm really curious as to why you guys are having issues?...let me know how your plugs look, gap and temp range.

 

whoa what? I obviously have missed something here. What have they done to gas?

 

I am more than up to date on my tune-ups. When I first got my car a while back, it had the stock, from the factory o2 sensor all busted up and exploded, old plugs, leading and trailing wires were in the wrong places, old oil, what I swear was probably fluid from the factory in the diff and tranny, and I still didn't get as much of an impact on gas mileage that e10 has.

On normal gas, in normal driving conditions, no beating on it, not going over 2500 rpms (seriously), I would be getting 275 miles to a tank. On E10 I get 240-250

You guys can argue all you want, tell me to tune my shit up and get it checked out. Or tell me to spend oodles of my fucking money putting in high compression rotors, boost it, and tuning it, and get over it. I'm sorry, but it's not worth my god damn time or the effort. I like my fucking NA car. And I want my fucking regular gas.

 

wow, a bit angry and at the wrong people...
anyhow, rotary motors will have more issue adapting to fuel containing ethanol just because of the fuel's burn rate. A rotary has a very short period of duration for combustion (typically referred to as constant volume combustion...think of dwell) in comparions to a piston motor.

I see you also lost, probably 2-3 mpg (guessing tank size). Right?

I don't know why Mazda has issued the warning for rotary motors, be it fuel system, the engine internals themselves or just because the motor will have issues running (idling could become a PITA). Anyone know more on the bulletin, as I'm intersted.