: Ethanol Blends



AJxtcman
09-13-09, 03:19 PM
If your Target AFR in the PCM is set for 14.7 to 1 and you are running E10 in your car this is equivalent to 15.3 to 1 on E0

Max Fuel Economy for E0 is 15.4 to 1
I think the government looked at that when going to E10

Some additional information on Ethanol

http://www.monodax.com/forums/off-topic/1967-ethanol-blends.html

http://forum.efilive.com/showthread.php?t=11752

AJxtcman
09-13-09, 03:28 PM
Running a car on the lean side can cause premature Catalytic Converter Failure

Has anyone seen a converter fail recently?

Krashed989
09-14-09, 01:09 AM
So basically what you're saying is that we should adjust the fuel trim to richen each bank a little so that you achieve the optimum ratio. Am I right? Or is that just for less emissions?

In an OBD-I caddy is it possible to edit the fuel trim through the dashboard diagnostics?

AJxtcman
09-14-09, 07:00 AM
Actually the Stoich setting or O2 switching point need to lowered to 14.11 instead of the 14.7 traditionally.
This is about 4% richer, but a lot of tables are figured off of the Stoich setting and they would be all off also.

The fuel economy should drop 4% to 10% if this is corrected.

Krashed989
09-15-09, 04:13 AM
So basically we would all have to send our PCM's to you huh? What about if we install a piggyback ECU? or replace the PROM chip with one tuned that way?

AJxtcman
09-15-09, 01:26 PM
So basically we would all have to send our PCM's to you huh? What about if we install a piggyback ECU? or replace the PROM chip with one tuned that way?

NO!

What I am stating is the Government looked at all of the information and allowed E10 to be placed in the market knowing what the effects are.
Decreased Performance
Increased Fuel Economy
Possible Converter Failure
Oh and the foreign oil thing also

piggyback what?
proms are done up by Westers

Krashed989
09-15-09, 11:08 PM
NO!

What I am stating is the Government looked at all of the information and allowed E10 to be placed in the market knowing what the effects are.
Decreased Performance
Increased Fuel Economy
Possible Converter Failure
Oh and the foreign oil thing also

piggyback what?
proms are done up by Westers

Ahh, I see.

Piggyback ECU (Engine Control Unit). I've been working on too many other brands of cars.

I think I would rather the fuel economy right now anyway. :cool:

AJxtcman
09-16-09, 06:58 AM
I hear a lot of garbage about so called piggy-back units, but that is the piggy back ECU's.

Most AFTERMARKET Wide-Band O2 sensor modules have the ability to change the switching point aka Stoich aka Lambda.

If you dropped the cash for 2 Wide-Band setups and changed the switching points to drop the AFR or Lambda down to 14.11 you would solve a piece of the puzzle, but your EQ ratio or Lambda ratio in PE would be off yet.

Now if you purchase a Programmable Aftermarket MAF you could correct the EQ ratio or Lambda ratio in PE

Now you are into the car $1500 just to correct AFR for any Ethanol blend you would come across. The car would out run any other FWD Cadillac, but the fuel economy would be terrible. Although it would be correct. YES MPG can be figured out by math also.

AJxtcman
09-16-09, 07:01 AM
The sheet is not finished
Ethanol vs Gas Stoich.xls (http://www.monodax.com/forums/attachments/off-topic/1140d1251043839-ethanol-blends-ethanol-vs-gas-stoich.xls)

AJxtcman
09-16-09, 07:24 AM
This is how you would adjust the switching point
Adjustable narrowband oxygen sensor output for ECU (http://www.zeitronix.com/questions/NBpoint.htm)

This is a Digital Ethanol Content Analyzer
Ethanol Content Analyzer (http://www.zeitronix.com/Products/ECA/ECA.htm)


A programmable MAF
AB-DBX85 85mm mass air meter (http://www.abacoperformance.com/Media/Fastest-Street-5.09.pdf)

I came up with about $1200 from Zeitronix and another $380 for the MAF. Then to have it installed and the MAF tuned say another $1000.

So just over $2500 you can have a rocket that runs on E85 safely and gets terrible MPG

Oh BTW you get more power from E85

AJxtcman
09-16-09, 07:36 AM
This is how you would tune a MAF sensor
Sorry it is a ford, but it is the only one I have posted. I have tooooo many attachments here to upload one of my GM MAF xfer recalibration sheets.

Ford MAF xfer worksheet (http://www.hptuners.com/forum/attachment.php?attachmentid=20015&d=1252157234)

The GM MAF xfer is done in hertz, but it is the same basic concept