260zShooter Posted June 16, 2008 Share Posted June 16, 2008 We've only had the Ethanol blend in Dallas, Tx for a couple of years now. Gas milage sucks and power is down. Oh yea it gets better, the price of oil has just gone over $140 a barrel. Great. Quote Link to comment Share on other sites More sharing options...
Gollum Posted June 16, 2008 Share Posted June 16, 2008 Someone told me ethanol has a higher octane than gas. I also heard they are discovering because of the high octane it has been found to damage either the injectors or the spark plugs... Complete bunk. Higher octane doesn't kill engines. Injector cleaner is basically an octane booster. Guys use it all the time with no issues. The issue here has been well covered. Methanol, and ethanol (so basically all alcohol fuels) have a lower air/fuel ratio requirement. Just go look at the threads about meth injection floating all around the board. You can't run 10.5:1 and expect safe power. If you were running 100% meth it'd be much MUCH lower, though I'm not sure what (around 7:1 iirc, though i'm really not sure). So what's happening is the fuel just knocks much sooner because the computer is adding fuel based off of fuel tables designed for gasoline. If the ECU was adding the right amout of fuel (amounts that would CHOKE your engine using pure gasoline) then you'd have LESS knock, and would see the effect of the higher octane. Some cars are compensating for the fuel by using O2 readings, but really the ECU is acting as though the O2 sensors are reading off. Few cars will make the corrections proporely as they keep adding ethanol to our gasoline. In reality cars SHOULD be taken to the factory and retuned. Who's gonna pay for it isn't part of my post though, that's just the reality. Cars need to be retuned. Carb'ed guys have it lucky. They can just adjust the carbs. Thier equipment will work just fine. Guys like me with OLD efi have it the worst imo. Who's gonna be able to retune our ECUs? Nobody. We'll be stuck being forced to use an aftermarket EFI system, or moving to a newer OEM EFI. The really tough part about this is that technically it's illegaly to modify your air/fuel ratio. That's what the CARB certification is about. Anything that modifies air or fuel flow in the intake or exhaust needs to be approved. So things like injector swaps, megasquirt, intakes, headers are all illegal unless approved. This means retuning your ECU is illegal to, which is a step that's going to be required as they keep adding ethanol. Look on the bright side if you can though. People like garrett might not need to use meth injection in 5 years if they keep adding ethanol at this rate. Quote Link to comment Share on other sites More sharing options...
SLVRBLLT40 Posted June 17, 2008 Share Posted June 17, 2008 The myth with the Hot Rod guys in general is that modern day, California gas (all gas here is 10% ethenol) is total junk. They base this on the fact that it doesn't contain lead (even though lead hasn't been in gas since 1973) and since all muscle cars died in 1973, that must mean the quality of gas died too. Total bologna. The main problemos with ethenol is gas is that A.) There's a pretty major hit in gas mileage. I think from 100% gasoline to 100% ethenol, it's a 30% drop or something like that. B.) Ethenol eats old cars. The fuel lines, the carbs, the fuel pumps, the tanks, pretty much everything in the fuel system. If you've ever opened up your carb and saw little white crystal babies in there, that's from the alky in the gas. Everything else about ethenol is good. Without ethenol, 11.5:1 on street car would be impossible, since the alky content does lower the combustion temperature. Quote Link to comment Share on other sites More sharing options...
AK-Z Posted June 17, 2008 Share Posted June 17, 2008 I just skimmed what was posted from my last post, so i might have missed a lot. I heard that ethanol damaged injectors over time as well. Something about the rubber seals degrading faster than normal because of the solvent effects it has one the oils in the rubber. if you think about it, alcohol has similar effects. I think of ethanol as a "different fuel." it is not gasoline. I know some supercars actually can produce more HP with ethanol, but MPG decreases, that's how it usually works. Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted June 17, 2008 Share Posted June 17, 2008 yeah, it's possible to run much higher compression on something like E85, BUT if you EVER put normal gas in it, it'll knock like a bitch and hurt the engine. to convert an old car to use ethanol you need to get rid of any natural rubbers and gaskets, and replace them with synthetics that can handle alcohol, otherwise you get that problem with everything getting eaten up. ECU's definitely need to be retuned, but i really doubt anyone will do anything to help anyone get that done. basically, there isn't anything too bad about ethanol IN A CAR THAT IS BUILT FOR IT, except a slight decrease in efficiency. there wouldn't be a drop in power, simply because it was built to run it (high compression engine/high boost engine) oh well, we'll see how things pan out over teh next few years. Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted June 17, 2008 Share Posted June 17, 2008 BillZ260. As far as I can remember, the Sunoco 94 has always said on the pump that it has 10% ethanol. Hence the "clean burn hi-performance" fuel that they advertise. The next highest octane is 91, though I recall Pioneer fuel sold a 93 octane for a while (at least while they were in my area) Back in the day, I questioned the ethanol, and thought that it just made it "better" but hey I was young, and knew 10X more about webers than I did about gasoline. Quote Link to comment Share on other sites More sharing options...
Nizm0Zed Posted June 18, 2008 Share Posted June 18, 2008 ok, im stretching on this one, cause its been a while since i heard it, But. I remember hearing that when the ethanol burns, it also releases an Oxygen portion, that oxygen portion needs to be compensated for with a bit more fuel, if the fuel mix isn't increased slighty over the equivalent 'full petrol mix' (gas for you guys) then the engine will run lean, and detonation is more likely, leading to ECU's that retard the timing slightly. I had a very quick look on google for some info, but have come up blank at the moment. Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted June 18, 2008 Share Posted June 18, 2008 it's not that it releases an oxygen portion (since if you compensated with making it richer, it'll release a proportionally higher oxygen "portion"), it's just that 100% ethanol's stoich ratio is 9:1. which is why you need to run a "richer" mixture than normal gasoline. Say you ran E10 (10% ethanol) its stoich ratio is about 14.13:1 gasoline is 14.7:1 so compared to gasoline, you need to run "richer" when compared to ethanol, gasoline runs "leaner" so if you kept the same settings and pumped in E10 your car would suddenly run lean. you'd have even more issues if you ran E85 i was looking at the wiki article, and when ethanol combusts, it produces water, co2, and heat. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted June 18, 2008 Author Share Posted June 18, 2008 Say you ran E10 (10% ethanol) its stoich ratio is about 14.13:1 gasoline is 14.7:1 so compared to gasoline, you need to run "richer" when compared to ethanol, gasoline runs "leaner" so if you kept the same settings and pumped in E10 your car would suddenly run lean. you'd have even more issues if you ran E85. That doesn't make sense. 14.13:1 is more rich than 14.7:1 so why would you have to run it "richer". I think you got your numbers mixed up somewhere because you would have to run E10 leaner to get the same AFR according to those numbers you posted. Quote Link to comment Share on other sites More sharing options...
Gollum Posted June 18, 2008 Share Posted June 18, 2008 No... He's right. 10.5:1, used for general max HP is richer than what you run on the highway, 15:1. Ethanol's stoich is 9:1, so you mix 10% of that with gasoline and now stoich becomes 14.13:1 First number is air, second is fuel. Less air means richer. Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted June 18, 2008 Share Posted June 18, 2008 Exactly. you don't want to run 14.7:1 with E10 that is considered "lean" for alcohol. 14.13:1 is the E10 equivilant of running a car at 14.7:1 with gasoline. Quote Link to comment Share on other sites More sharing options...
mobythevan Posted June 18, 2008 Share Posted June 18, 2008 Are you guys sure about the AFR, because I think it is easy to get confused if you are not using lambda values. I was told if your wideband gauge is set up for gasoline it reads 14.7 at stoich (when all oxygen is burned). It also reads 14.7 with E10 when all oxygen is burned even though stoich would be some lower number like you say 14.13. I think if you work in AFR you really have to change your gauge calibration everytime you change fuel if you want all the numbers to make sense in the end. Or you take the standpoint that even though the gauge reads 14.7 with E10, it really means you are running 14.13. Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted June 18, 2008 Share Posted June 18, 2008 Are you guys sure about the AFR, because I think it is easy to get confused if you are not using lambda values. I was told if your wideband gauge is set up for gasoline it reads 14.7 at stoich (when all oxygen is burned). It also reads 14.7 with E10 when all oxygen is burned even though stoich would be some lower number like you say 14.13. I think if you work in AFR you really have to change your gauge calibration everytime you change fuel if you want all the numbers to make sense in the end. Or you take the standpoint that even though the gauge reads 14.7 with E10, it really means you are running 14.13. I forgot to explain that when running 14.13 on E10 an AFR gauge will still show 14.7 I've heard people saying using an O2 sensor to tune a car isn't as good as if you go by the Lambda values. Quote Link to comment Share on other sites More sharing options...
mobythevan Posted June 18, 2008 Share Posted June 18, 2008 I forgot to explain that when running 14.13 on E10 an AFR gauge will still show 14.7 I just wanted to make sure I understood that fact correctly since I am getting ready to change to E85. Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted June 18, 2008 Share Posted June 18, 2008 I just wanted to make sure I understood that fact correctly since I am getting ready to change to E85. Yeah. you'd have to recalibrate your gauge to display the afr right. What the o2 sensor looks for is free oxygen, so as I under stand from what i've looked up, when running E10 at 14.13:1 there's as much free oxygen from the complete burn as straight gas is at 14.7:1, so the gauge shows up as 14.7:1 even though the true ratio is 14.13:1, which is why you should adjust the ratio by using the lambda voltage instead of what the gauge says, or something along those lines. Quote Link to comment Share on other sites More sharing options...
aziza z Posted June 19, 2008 Share Posted June 19, 2008 Do we have 10% mix in cali? I didnt notice if we did. I usally have no choice anyway. When i need to fill up i need to fill up. Always put in 91 octane in all my cars anyway. Quote Link to comment Share on other sites More sharing options...
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