e85

[SpyhunteR]

in day to day usage your fuel in the car wont' get contaminated to make a noticeable detriment to performance.

Now storing 300 gallons in barrels, THAT'S asking for trouble imo. As that will be sitting for some time.

I wouldn't worry about the gas tank full of E85 being a danger except if you're going to let it sit for a good long while.

[peppermill]

The level of stupid here baffles me. Serious, unadulterated stupid. The constant assumption that everything is going to end badly has me wondering how anyone can innovate anything?!?! It also has me wondering if I'm very much in the wrong place to post this adventure. Sharing this with this board feels a lot like peeing in to the wind. Or arguing with kindergartners. Maybe a little of both. Can anyone recommend a tuner board to continue this technical discussion? Preferably one that has Grand Am tuners on it?

It's my own personal gas station. A 300 gallon fuel storage tank/dispenser, with nozzle, filter, meter, etc. Like a gas station, only smaller. First it was all about leaning out blowing the motor, and now water absorption? Give me a break!! What do you guys base this on? All your own experience with ethanol? No. That's definitely not it. How about big oil ethanol smear propaganda? That seems much more likely. I've taken E85 in small bottles and added water. It'll take quite a bit before you get phase separation. More than 10%. So that fuel storage tank would have to pull 30 gallons of water out of the air over the next few months when it's all used up. Anyone want to place bets on that happening? So for all you ethanol haters, (big oil & OPEC lovers!) it's a non issue, OK?


There are 300 million gallons of ethanol production less than 40 miles away from me, with another 200 million gallons a year under construction that will be operational by late 2008. (Just in time for harvest... maybe we won't have as many multi million bushel piles of corn sitting on the ground next spring!) Ethanol sells for $2.50 a gallon at the refinery. If you all like paying $3.50 for gasoline, and sending $2 of that out of the country, that's fine. Keep buying your gasoline and bad mouthing ethanol and my efforts to burn it. For the same gallon of fuel, I'm paying less and I'm sending 27 cents out of the country. The rest stays in the USA circulating around our economy. Not the economy of some other country. I'm not in the market to run out and buy a new flex fuel vehicle. Especially when I know that a current vehicle can be converted for little to nothing.

[peppermill]

So the numbers from the scan gage have me somewhat wondering about what is normal for knock? On normal fuel, there's knock that starts at 3K, depending on throttle and engine load, and it comes and goes, peaking up to 10 degrees of knock or so somewhere around 4500 RPMs.

On E85, it takes 4K on the Revs and more throttle before there is any knock at all, and the knock retard is much less. Just a few degrees, tops. Getting on the throttle more causes a more knock once I get in to enrichment mode. It's gets out of hand above 5200 RPMs. Goes to nearly 20. So keeping it out of open loop and the revs low seems to be the key here. I'm guessing that's related to the fact that the long term trim goes to 21.8 under E85. Shock24Z said "your fuel trims will likely be jacked." That's an understatement. 21.8 seems to be the limit. Short term corrects on top of that, and floats around 10 or so. The long term can't enrich enough, so short term adds to it, and short term goes away for open loop mode (effectively leaning it) So as long as the PCM stays in closed loop, (less than 70% throttle) and the engine revs stay low (less than 4K) E85 doesn't seem to be an issue on a stock Grand AM GT. There seems to be plenty of injector under these limits even with a totally stock setup. The next thing I'm going to do is start down the path of making this an idiot proof setup. I'm thinking if I lengthen the throttle cable, or simply shim the accelerator peddle, I can keep the throttle at less than 60% (to give myself a margin of error).

[peppermill]

My fuel tank is still not 100% ready, so I've been blending down, to roughly 50% E85. That seems to be the ideal blend for having no issues at all. No "jacked fuel trims." Skewed? Yeah, but not jacked. :-)

The least knock, no service engine light, etc. I was fixing a computer network at a GM dealer and talking to the service manager while I was doing it, and asked him the difference between the injectors in the Impala LT 3500 flex fuel, and non flex fuel versions. I was trying to figure out what flow rate injector would be ideal, and the 3500 seems pretty close to the 3400. He grinned wide and said that he was trying to figure out how to do the same thing that I was doing. He said all the Flex Fuel stuff was "stainless steel guts in the injectors, stainless fuel pump, stainless fuel rail... it's major expensive to change it all." So we discussed that all that was due to FFV needing to be compatable with methanol, not ethanol, and he was excited to place a tech2 on the Grand Am and see how it dealt with the E85. I'll let you know how that all turns out.

[Shock24Z]

Originally Posted by peppermill

So the numbers from the scan gage have me somewhat wondering about what is normal for knock? On normal fuel, there's knock that starts at 3K, depending on throttle and engine load, and it comes and goes, peaking up to 10 degrees of knock or so somewhere around 4500 RPMs.

On normal 89 octane? ... no ethanol? Thats surprisingly high.

On E85, it takes 4K on the Revs and more throttle before there is any knock at all, and the knock retard is much less. Just a few degrees, tops. Getting on the throttle more causes a more knock once I get in to enrichment mode. It's gets out of hand above 5200 RPMs. Goes to nearly 20.

20 degrees of KR? I'm fairly certain it should max around 14*

So keeping it out of open loop and the revs low seems to be the key here. I'm guessing that's related to the fact that the long term trim goes to 21.8 under E85. Shock24Z said "your fuel trims will likely be jacked." That's an understatement. 21.8 seems to be the limit. Short term corrects on top of that, and floats around 10 or so. The long term can't enrich enough, so short term adds to it, and short term goes away for open loop mode (effectively leaning it) So as long as the PCM stays in closed loop, (less than 70% throttle) and the engine revs stay low (less than 4K) E85 doesn't seem to be an issue on a stock Grand AM GT. There seems to be plenty of injector under these limits even with a totally stock setup. The next thing I'm going to do is start down the path of making this an idiot proof setup. I'm thinking if I lengthen the throttle cable, or simply shim the accelerator peddle, I can keep the throttle at less than 60% (to give myself a margin of error).

I'm not a big fan of this plan. But I can't say that it would certainly fail. There are definately gains to be had by tuning though... namely milage and longevity of your motor. You sound like you already have a basic understanding of tuning so if you were to purchase a tuner you could handle tuning this car with a little reading. Your best bet on getting a powrtuner would probably be on the clubgp classifieds. Otherwise HPtuners are available anytime.

Can anyone recommend a tuner board to continue this technical discussion? Preferably one that has Grand Am tuners on it?

I did on page one. But like I said you need to be a Powrtuner owner to access that page.
http://www.powrtuner.com/index.php?s...677&hl=ethanol

[Malaclypse]

You should have absolutely no KR at any RPM on normal fuel. If there's any more than 5 degrees of KR going on at light throttle you may have carbon deposits or some other sort of internal engine problem.

The fact that Ethanol eliminates that knock in closed loop further proves this due to the increased octane. Its only a band-aid fix, however. As whatever problem it is worsens, so will the knock. Once that pre-ignition problem returns and you're running ethanol you'll be dancing on a fine line with your engine's health.

I'd suggest you find the source of your detonation and fix that before proceeding with your test.

[cardude007617]

i think what made most people be against you from the beginning was that you were dumping fuel with higher than normal amounts of ethanol into a vehicle that wasn't meant for it with no modifications to handle it or any equipment to make sure everything is working correctly.
we ALL would love to pay less for gas, and if this works maybe one or two of us will follow suit. it's all about how you go about it.
don't let the members on this forum get you down and irritated; its normal everyday stuff here.

[AleroB888]

Originally Posted by peppermill

So the numbers from the scan gage have me somewhat wondering about what is normal for knock? On normal fuel, there's knock that starts at 3K, depending on throttle and engine load, and it comes and goes, peaking up to 10 degrees of knock or so somewhere around 4500 RPMs.
..........................

I'm thinking if I lengthen the throttle cable, or simply shim the accelerator peddle, I can keep the throttle at less than 60% (to give myself a margin of error).

The scan graphs here are of a stock '03 Alero 3400;
In a 15 minute scan of typical driving, this is the most KR that showed up :

http://shutter12.pictures.aol.com/da...fLiQVE0300.jpg

Here is a WOT run at the track, with a moderate power-braked launch. However, the run just preceeding it showed much less KR.

http://shutter15.pictures.aol.com/da...xwxecP0300.jpg

I would say it's normal to get some KR on the stock vehicle using regular gas. But I don't think pulling up a steep grade (to take one example) with a throttle position restricted to 60 % would be realistic, certainly not at this altitude.

[peppermill]

Originally Posted by Shock24Z

On normal 89 octane? ... no ethanol? Thats surprisingly high.

Correct. That's not transient driving, that's steady state, 2 mile hill, exceeding the speed limit, bucking the wind, and riding the breaks a little. Numbers bouncing all over the place don't do it for me. I need to hold a steady state to let the numbers all settle down. I don't like a fluke number here and there, I like repeatability.

To get that, I'm basically doing everything I can to keep the engine at some level of maximum load for as long as possible. That's usually a time span of about a minute, before I run out of road, and that generally will exceed all forms of normal driving.

Transient, on no ethanol fuel, I see about 5 degrees of knock, WOT, really abusing the motor. So I would guess it's pretty close to normal.

My service manager ride with a tech2 yeilded nothing. He didn't understand the difference between closed loop (using the 02 to adjust short term, that then pushes long term on an averaging set up for each rpm/load) and open loop. He wouldn't accept that the oxygen sensor is ignored in power enrichment mode when the commanded A/F goes to 12.7. ("Hey, it just changed to 12.7:1! There's your problem!") I explained that it does that by design, on all fuels. It's called power enrichment mode. Seemed to be a foreign concept to him. I kept explaining that it's not a wideband, and the 02 can't give a reading outside of a 14.7:1 average. But he just wouldn't accept it. He was the service manager, he knew best.

He kept getting hung up on the fact that the computer couldn't adjust air fuel ratio because it didn't have an alcohol sensor. And wouldn't believe me that all the alcoholl sensors are eliminated on newer flex fuel vehicles. It's like he thought I was just making everything up. And I quote the service manager, one last time: "When a flex fuel vehicle isn't running right, the first thing we do is replace the alcohol sensor!"

Don't worry guys, I've never taken a vehicle there. And won't. Ever.

[SpyhunteR]

When I'm on E85, I'll show you how it's done.

And fix your knocking.

[AaronGTR]

Originally Posted by peppermill

Transient, on no ethanol fuel, I see about 5 degrees of knock, WOT, really abusing the motor. So I would guess it's pretty close to normal.

You'd be guessing wrong. A properly functioning car on the correct fuel and with no mechanical or electrical problems should not see ANY knock, even at WOT. Heck I never used to get any knock even running boost with stock injectors and programming. All I was using was an fuel pressure riser and 93 octane gas. It would lean out towards red line but still stay below the 14.7:1 AFR mark (according to the wideband on the dyno). If you're getting a ton of knock, there's either something wrong with the engine, or [gasp] you're using the wrong fuel! There could have been residual ethanol in the tank when you where getting that 5 degrees of KR and you thought it was on normal gas.

[Shock24Z]

I'd say 1 or 2 degrees here and there on a stock motor is not uncommon and entirely survivable especially on a naturally aspirated application. However, I could see 5+ degrees causing some fatigue to the motor over time. If you wish to continue without tuning its definately something to avoid.

[SpyhunteR]

guessing doesn't win the day.

[Malaclypse]

Originally Posted by Shock24Z

I'd say 1 or 2 degrees here and there on a stock motor is not uncommon and entirely survivable especially on a naturally aspirated application. However, I could see 5+ degrees causing some fatigue to the motor over time. If you wish to continue without tuning its definately something to avoid.

Based on my experience, most normal knock is related to snap-throttle actions when at a standstill.

I've observed this in many different vehicles in varying states of repair. Being at sea level does modify this observation somewhat, however the powertrain controls do use input from the Barometer in the MAP sensor for some adjustments. GM hasn't accurately described those adjustments and I've personally never bothered to dig deeper but I'm fairly sure timing advance would be one of them.

All of my readings have been made with a Tech 2 with the latest software.

[peppermill]

So what I've discovered thus far is that if you want to run E85 in a Grand AM, with zero mods:

#1 is a maybe... not sure what the deal is there, but thought I'd mention it.

1)Use cheapo champion copper core plugs. Not sure why, but platnum tipped ones made funny noises, and then started to misfire. Again... I'm stumped on the cause/effect going on there. Not sure that I want to take the time and effort to investigate it, or if it's even really a problem, as my dolt of a mechanic may have had the wrong plugs entirely.

2)Fuel with engine running, warmed up and in closed loop, AC turned on. Try not to catch yourself on fire while doing this.... but if you do, know that E85 burns with bright yellow flames (very little smoke though) and unlike the F-1 guys, everyone will actually get to see the flames on you. :-)

I haven't been brave enough to go from E0 to E85 on a cold engine, and am not sure what would happen, if the idle would be able to adjust without being in closed loop.

3)Keep it under 60% throttle. By doing this, RPMs will rarely exceed 4K RPMs, the pulse widths will be sufficient, and you won't lean out, because it'll stay in closed loop.

4)Pull the codes and pull them often.

5)Don't get annoyed if you wreck something.

Now I enter the stage where I see how many miles I can do this. So far, it's about 8K on mixed high blends to mid blends of E85. Maybe this is bound to fail, and I just haven't given it enough time yet.

[peppermill]

I posted this out of order, it should have been BEFORE the last post. Doh!




I was on a trip, and got the low fuel light, and swung in and filled up with E85.

Something I've found is that when you fill with fuel, whatever you're putting in seems to go directly to the sump, and hits the injectors about 5 seconds after you pour it in. I've also found that running the AC prevents idle hunt when the PCM is doing panic adjustments to the trim tables. Without the AC on, it surges when changing to or from E85, but with the AC on, the only thing that changes is pulse width and long term fuel table on the scan gauge. Yes, I fuel with engine running when doing drastic changes to fuel blend. I don't want to get stranded because of a start in open loop mode.

I had gotten 22MPG in all sorts of mixed driving on E40 the prior tank by the way. The mileage variation seems like it's more based on driving style and short vs long trips than fuel mixture. I was also getting that mileage or better on straight E85 at times.

So after I fill up, I'm really looking things over, and keeping an eye on things. No knock retard, nor a misfire. Not a one. Almost running TOO good! Long terms all pegged at 21.8 again, and short terms float in the 6-10 range. Lean code tripped of course. Scan gage is set to kick the red lights on at anything greater than 59% throttle. Keeping the throttle under 60% keeps the RPMS under 4,000 (or 42-4400 depending on terrain.. either way, the pulse width stays under 16ms).

[Pete]

I light of the rising cost of gas and the availability of E85 locally at $1.00 a gallon cheaper than regular gas, I have converted my 3400 powered GA to E85.

The only thing absolutely necessary is to install larger fuel injectors.
I will be doing some tuning as well when my tuning software shows up.
For now it is running 50% ethanol. The fuel trims in in the -7 to -12 range with this mixture with no other changes being made at this point.

[peppermill]

Originally Posted by Pete

I light of the rising cost of gas and the availability of E85 locally at $1.00 a gallon cheaper than regular gas, I have converted my 3400 powered GA to E85.

The only thing absolutely necessary is to install larger fuel injectors.
I will be doing some tuning as well when my tuning software shows up.
For now it is running 50% ethanol. The fuel trims in in the -7 to -12 range with this mixture with no other changes being made at this point.

Awesome!

I've found that on stock injectors anyway, there's a huge difference in trims between E50 and E75, and then another jump at E85.

I drove 500 miles on E85 today. $3.09 in Marion Iowa, $2.74 a gallon in Grimes, IA. 18MPH on one tank, (too much city driving on the first tank) 22MPG on the other tank, and I'm not sure what I've got on my remaining tank, and was too tired of spending $$$ on fuel to swing and in fill up at the end of the day. I was getting some knock retard with when accelerating to get on to the interstate, (some of that probably due to the fact that I was intentionally pushing it right to the edge of causing knock retard) but no problems with the AC on and cruise set at 80, doing hills. Timing stayed around 50 degrees or so.

And my 300 gallons of E100 will be delivered on Monday, for blending. The problem is that I have to drive 6 miles before or after adding the E100 to get normal fuel. So if I do 4-5 gal of E10, and the rest E100, the end blend will be OK, but there will be E100 surging through the fuel system after filling until it blends and mixes. That has be concerned.

I need bigger injectors to do this right.... I miss WOT.

And another fuel tank to mix.

[AleroB888]

Originally Posted by peppermill

Awesome! ....................... I was getting some knock retard with when accelerating to get on to the interstate, (some of that probably due to the fact that I was intentionally pushing it right to the edge of causing knock retard) but no problems with the AC on and cruise set at 80, doing hills. Timing stayed around 50 degrees or so.........................

How/when are you getting a reading of 50 degrees of timing?

[torq455]

did anyone suggest adding about 30% more fuel when running E85? there's a guy with a turbo 3400 doing it after much research and it's running great!