Can our cars Run on e85
05-07-2006, 11:20 AM
#41
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Hi,
Sorry to say, GM has closed public acces to the "Tech line" site.
But when it was open, i found GMs official statement of what can happen if you run your non E85 car on this stuff.
There was the obvius warnings about MIL/SES on, but that´s of no concern if you are converting your car.
The other warning was that E85 MIGHT cause accelerated corrosion.
Nothing on the subject of rubber part damage.
On the WWW there are a lot of sientific info on the properties of Ethanol and the E85 blend. There you can read that the risk of corrosion starts when the water contet is above 0,5%. At least here in sweden the E85 fuel contain a lot less water than that. (can you say a lot less??)
I have converted my Tahoe, and it runs perfectly. ( HP Tuner)
If I want to "flex fuel it", I just set the stoich mid way betwen gas and E85.
The LTFT takes care of the rest.
Best result is acived by only using E85 and tune the PCM for that, but the LTFT takes care of the ocational emergency gas fill up, if E85 is unavalible.
There is a BIG movement in Sweden converting gas cars to E85, due to the gas prices over here. ( Gas 12,3 sek/litre E85 6,9 sek Litre)
You might want to take a look at this:
http://etanol.nu/forum/viewforum.php...5a0767acbacd9f
BR //
Sorry to say, GM has closed public acces to the "Tech line" site.
But when it was open, i found GMs official statement of what can happen if you run your non E85 car on this stuff.
There was the obvius warnings about MIL/SES on, but that´s of no concern if you are converting your car.
The other warning was that E85 MIGHT cause accelerated corrosion.
Nothing on the subject of rubber part damage.
On the WWW there are a lot of sientific info on the properties of Ethanol and the E85 blend. There you can read that the risk of corrosion starts when the water contet is above 0,5%. At least here in sweden the E85 fuel contain a lot less water than that. (can you say a lot less??)
I have converted my Tahoe, and it runs perfectly. ( HP Tuner)
If I want to "flex fuel it", I just set the stoich mid way betwen gas and E85.
The LTFT takes care of the rest.
Best result is acived by only using E85 and tune the PCM for that, but the LTFT takes care of the ocational emergency gas fill up, if E85 is unavalible.
There is a BIG movement in Sweden converting gas cars to E85, due to the gas prices over here. ( Gas 12,3 sek/litre E85 6,9 sek Litre)
You might want to take a look at this:
http://etanol.nu/forum/viewforum.php...5a0767acbacd9f
BR //
05-07-2006, 02:46 PM
#42
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Originally Posted by tahoe
I have converted my Tahoe, and it runs perfectly. ( HP Tuner)
If I want to "flex fuel it", I just set the stoich mid way betwen gas and E85.
The LTFT takes care of the rest.
If I want to "flex fuel it", I just set the stoich mid way betwen gas and E85.
The LTFT takes care of the rest.
Can you explain EXACTLY how you do this with your tuner?
05-08-2006, 12:15 PM
#43
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Can you explain EXACTLY how you do this with your tuner?
Do you use a PC tuning software or are you familiar with the fuel metering functionallity of a PCM?
Just asking to make my explanation making sense.
BR//
05-08-2006, 12:24 PM
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Originally Posted by tahoe
Yes I certanly can do.
Do you use a PC tuning software or are you familiar with the fuel metering functionallity of a PCM?
Just asking to make my explanation making sense.
BR//
Do you use a PC tuning software or are you familiar with the fuel metering functionallity of a PCM?
Just asking to make my explanation making sense.
BR//
05-08-2006, 01:24 PM
#45
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Install bigger injectors, Change your stoich to 9.76 and retune your VE... after that you can increase timing.
There is a thread about this somewhere on this board.
There is a thread about this somewhere on this board.
05-08-2006, 01:28 PM
#46
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Hi,
Ok this is what I have done to make my stock T-code 5.3 My 03, run on E85.
Changed the stoic from 14,63 to 10,5, witch results in a LTFT of around 0% to -2% with the fuel I am using.
Increased the after start enritchment in the ECT range 0 to +30 degre C.
Increased the idle timing at MAP higher than 50 Mpa, this is to help the engine fire up.
Once at idle, the MAP is mutch lower, so the change has no effect on idle once the engine is running.
(I had long cranking/died after first start at this temp, solved it.)
Copied the max torque timing table to the high octane timing table,
and gave it the normal LS-1 aperance at WOT.
Knock is non existent running E85.
I had already dialed in the VE table in SD mode before starting the E85 tuning.
It´s actually this simple!
The truck is running Very god!
Br//
Ok this is what I have done to make my stock T-code 5.3 My 03, run on E85.
Changed the stoic from 14,63 to 10,5, witch results in a LTFT of around 0% to -2% with the fuel I am using.
Increased the after start enritchment in the ECT range 0 to +30 degre C.
Increased the idle timing at MAP higher than 50 Mpa, this is to help the engine fire up.
Once at idle, the MAP is mutch lower, so the change has no effect on idle once the engine is running.
(I had long cranking/died after first start at this temp, solved it.)
Copied the max torque timing table to the high octane timing table,
and gave it the normal LS-1 aperance at WOT.
Knock is non existent running E85.
I had already dialed in the VE table in SD mode before starting the E85 tuning.
It´s actually this simple!
The truck is running Very god!
Br//
05-10-2006, 03:21 PM
#48
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Alcohol REALLY doesn't like to burn well when things are cold, so startups would usually be a challenge depending on your % alcohol.
Ideally you'd use a different fuel for starting.
The alcohol needs heat. You cannot increase static compression on-demand so the next best thing you can do is increase the heat by starting the spark sooner. Heat will increase a limited amount (best you can do) around TDC and accelerate the burn-rate. This increases your chance of starting of course.
Every engine will be different and of course it will vary with engine coolant and air temp, but I think I'd start with around 10* additional at normal operating coolant temps, and I'd increase that at the lower coolant temps.
If stock said
180*F cranks at 5*
30*F cranks at 10*
then I'd try:
180*F cranks at 15*
30*F cranks at 22*
and adjust from there depending on how the starting went.
I've been doing some testing with acetone lately, and some of my results suggest that using it as an additive may help cold-starts. I know how the acetone acts when mixed with gasoline, and it does indeed change the starting and warm-up characteristics. I have not yet tried it in a heavy ethanol mix yet though. If I do I'll post the results of what happened.
Ideally you'd use a different fuel for starting.
The alcohol needs heat. You cannot increase static compression on-demand so the next best thing you can do is increase the heat by starting the spark sooner. Heat will increase a limited amount (best you can do) around TDC and accelerate the burn-rate. This increases your chance of starting of course.
Every engine will be different and of course it will vary with engine coolant and air temp, but I think I'd start with around 10* additional at normal operating coolant temps, and I'd increase that at the lower coolant temps.
If stock said
180*F cranks at 5*
30*F cranks at 10*
then I'd try:
180*F cranks at 15*
30*F cranks at 22*
and adjust from there depending on how the starting went.
I've been doing some testing with acetone lately, and some of my results suggest that using it as an additive may help cold-starts. I know how the acetone acts when mixed with gasoline, and it does indeed change the starting and warm-up characteristics. I have not yet tried it in a heavy ethanol mix yet though. If I do I'll post the results of what happened.
05-10-2006, 03:27 PM
#49
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Tahoe, thank you for posting that information.
It all looks reasonable and the only part I'd question about getting away with is the changing of the stoich AFR value and the stock narrowbands staying happy with so much % ethanol burning.
I'm also curious as to how much spark advance you had to add before getting an improvement in your crank/starting.
Would you mind posting your fuel mileage now converting to miles-per-gallon for us?
And have you tried adding a small amount of acetone to your fuel to see how that effects your starting & mileage?
It all looks reasonable and the only part I'd question about getting away with is the changing of the stoich AFR value and the stock narrowbands staying happy with so much % ethanol burning.
I'm also curious as to how much spark advance you had to add before getting an improvement in your crank/starting.
Would you mind posting your fuel mileage now converting to miles-per-gallon for us?
And have you tried adding a small amount of acetone to your fuel to see how that effects your starting & mileage?
