I forgot the math for AFR in PE Table

[2therock]

It's been a while and I forgot how to check the numbers in the PE table to come up with the AFR.

14.something devided or multiplied by a PE entry = AFR ratio.

Is it like 14.62857 / 1.24414 = 11.75797739804202099442184963107

Thanks, I'll write it down this time.

[gsegse]

( devide )

14.7 devided by PE table = your AFR command when you r in PE mode .

thanks

[69lt1bird]

Go to the Engine | Fuel Control | General tab in your file and see what stoich is, they are not all set at 14.7.

After that, decide what you want your PE ratio to be and divide the stoich number in your file by a number like 1.13, 1.14 etc to find your target.

14.62/1.13=12.94
14.62/1.17=12.5

[2therock]

Thanks Guys,

[dtsngit]

What all reasons would cause this formula to be off?

For example my buddies car: 14.6 Stoich Commanded

PE commanded: 1.3275

Actual WOT AFR from dyno wideband = 11.5 all the way across

But using the formula: 14.6 / 1.3275 = 11.0 AFR

So what could cause the discrepancy?

[angrygoat]

ve and/or MAF table is off

[Chevy406]

Set your PE table to the desired AFR at WOT first. Then go back and re-tune your VE and MAF tables. I learned this the hard way also.

[69lt1bird]

What Chevy406 said, plus the tailpipe wideband will always be off compared to one that is in the exhaust pipe or header where it should be.