Readjusting stoich for E-10.

[csementuh]

Thank you very much!

[tramotorsports]

You have to do more than just change the stoich values for the fuel. if you have a 0.85 Lambda commanded for a stoich value of 14.64 then the same lambda value is going to be different at a stoich value 14.4, or 14.2, or 14.0, and so forth.

.85 Lambda on stoich 14.64 = 12.44:1
.85 Lambda on stoich 14.2 = 12.07:1

[passingpower]

Ok. Your WOT PE fuel management is a lot more straight forward than for the 3800. Easier to tune even if a bit less flexible. The thing is, your EQ ratio uses the Stoich AFR as a starting point. So, when you adjust Stoich, you're also adjusting your PE AFR. Further, I looked at the resulting COMMANDED AFRs, and they appear to be tailored for your SC'd engine AT FACTORY BOOST LEVELS. I'm not familiar with pulley sizing for your setup but, I can make some general recommendations. Log your runs and increase your EQs for the RPMs you're seeing knock in. It really will be that simple (assuming your IFR is calibrated and your MAF tranfer function is tuned so that your LTFTs are 0.0.) If you put a smaller pulley on, you'll want to increase your EQs until KR just goes to zero. If you modify your boost bypass gate function to be more aggressive, move your EQ values to lower RPMs.

Now let me tell you why all the words for my previous explanation. I started out ASSuming you were running an L67 or L36 3.8L V6. The 3800 has a Stoich value to adjust AND a PE table that needs to be adjusted as well. The PE tables for the forcefed L67 are much the same as the NA L36 and badly need to be modified just to set them up. To complicate things, a time component is added to the PE scalar which, from the factory, makes for a table so fugly, only the EPA could love it. So, that doesn’t make setup any easier.

Remember, CALIBRATE your stoich AFR for the fuel you're burning, get your LTFTs to zero in idle cruise and WOT, use realistic WOT spark timing and only then use PE to fuel out your knock. A wideband O2 sensor will help greately but, that’s beyond the scope of this thread.

[csementuh]

Thank you for a much more thorough explanation. I need to get my PE and MAF dialed in better with my wideband, then I can work to get everything perfect. Thanks again!