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Dash 1 math and rpm help

Posted: Sat May 26, 2007 3:43 pm
by chumpy36
Hi Folks,

Having a little trouble setting up one of the displays on the dash 1. Here's what I want to do...

I have a wide band o2 sensor that outputs 1-5 volts. I have it going to Analog 2 on the DL1. I have an equation that interpolates the readings to Air Fuel Ratio.

=(v-1)/4 * (22.39-7.35) +7.35

I want to input this equation in the Dash1 setup so that on the dash1 it displays the AFR number and not the raw volts.

I see under input scaling there is a place to input an equation but I don't understand what to put in the fields. Can anyone help?

Also, I'm having some trouble getting rock solid rpm data. It tends to jump around a little bit. I'm using the 12v pulse train from the ECU of my car but at higher rpms the reading tends to jump around a bit making the warning lights come on at in accurate times. Do you have any filtering advice?

Thanks for any help

Jason

Posted: Sat May 26, 2007 5:08 pm
by jlucas
I think you might need to call Al on that one. I have no idea why dash1 equation area is different than the variable setup in the analysis software.

I guess you could build a the excel table from your known formula and then let the config pick it's own formula from that.

Posted: Sun May 27, 2007 3:26 pm
by RTUSA
Your wideband manufacturer gave you a more complicated equation than they needed to.

Doing a little algebra on your equation reduces it to:

3.76x + 3.59

which enters easily into the "Enter an equation manually" dialog box. Starting from the top you would enter:

0
0
3.76
3.59

Posted: Sun May 27, 2007 9:57 pm
by chumpy36
Thank You Al!

Jason