Gasoline around here contains 10% ethanol. With out testing the fuel should I be tuning for E10?

If it is in-fact 10%, target stoich AFR is about 14.1-14.2, correct?

What is an ideal AFR for WOT?

What is the ideal timing advance?

Currently I have WOT set about 12.2 and timing at 27*. I feel like it pulls hard but could pull harder.

The car is a 04 z06 with long tubes and intake.

 

Set up stoich 14.13

12.2 is pretty rich for an NA motor...try more like 13.0 or even 13.5 if you have good fuel

 

Wow 13-13.5 is really riding the edge of the envelope isn't it. Set your stoich to 14.13 and assuming you have done your VE table and MAF set your PE to 1.105 this will give you a PE A/F of 12.78 and you can play with it from there.

 

There is no reason for an NA car to run in the 12's on gasoline. I wouldn't cal 13-13.5 on the edge.

 

You mean other than knock margin, flame speed control and better torque by allowing timing closer to MBT, or exhaust component cooling to prevent catalyst or O2 failure? LBT fueling is not always the desired answer...

 

On 100% gasoline I would have to agree that in PE or WOT--13.0-13.5 on pump gas is asking for trouble--And it will most likely make LESS HP that lean--Race gas may help detonation from extreme timing but not a lean mixture
On a dedicated race engine I would set the AFR like 12.8-12.9
On a DD type care weekend racer more like 12.7-12.8
Race gas just lets you add more timing
With 10% Ethanol--you would need more fuel to compensate and can run more timing as Ethanol reponds well to timng
After about 2003 most every GM car/truck comes with an ethonal fuel and spark table---EVEN if the car was not equipted with the Flex Fuel option-It's still loaded into the ECM--- You can download the FREE demo program from EFILIVE from their website---Then go to http://holdencrazy.com---There they has most all STOCK GM tunes and even some Modified ones you can look at--Easiest would be to find a factory equipted flex fuel truck and see how the ECM compensates the fuel and spark both at Part throttle and at PE/WOT and go from there
The Ethonal fuel tables can accomodate mixes from 100% gas to as little as 5%--in increments of 5 i think---In between those #'s you would have to make a guessatmate
The spark table is different as I belive it uses either a plus or minus multiplier based on Ethanol mix %

 

Greg who cares about knock, the ECU will remove timing to fix that anyways
I think I am going to go out and dial my PE to go ahead and give me 14:1 AF lean is mean right

 

I would split the difference
It varies way to much pump to pump.

14.13 would be exact 10 percent ethanol content.
You cannot guarantee that ethanol content on a day to day basis.

 

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