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View Full Version : Datalogging with the AEM UEGO, and tuning advice wanted



Chrizar
09-29-2014, 01:17 PM
Obviously it's been done, I'm probably just looking over it though. I know to wire up the AEM to my ac switch, and with my ac being gone entirely I'm free to use that to monitor the afr at all times. I don't know the volts/afr numbers for the aem, i've seen the LC-1 info posted, not the AEM. I'm struggling with my AFR at wot being rich and the car not taking changes like I want it to. I probably need to get my VE tables in check a little better, but I took the car to the track, made 4 passes and only one of them I was close on afr.

Car always seems to have run in the 11's afr wise, mind you it's on an open Y pipe, someone stole my LM2 off the car.... My aem is in the pass side of the Y, just past the collector of my LT's.

All of my sensors are new, injectors from my logs show 83% max DC and are stock, fuel pump is stock as well, so i suppose it could be tapering off pressure up top or I'm more inclined to think a setting is off and it's adding fuel at wot still. My AFR vs coolant is 0 across the board and I have my afr graphed using excel to command around 12.8 from 2600 up to 6000 where my limiter is.

Just in case this has something to do with anything, here are the mods:
Pacesetter race longtubes, catless Y(open atm), slp lid swap, no emissions, no ac. All flags in my tune are off for CEL's related to emissions/ac, fans stay on to keep it around 195 running temp, added 2 degrees of timing, no knock, I'll have to log to check blm's again, and i forgot to run the tune through blm locker... I even tried pulling fuel using the maf tables, only a 5% change. I got it to 12.5 till mid rpm and it richened up according to my gauge around 4k maybe 4500. I did run a 13.45 @ 102.63 w/1.9 60ft this previous wednesday with a DA of 980 and AFR in the 11's the whole pass.

i want to wire the sensor up, and log it with tunerpro. Maybe someone will see something in the tune I don't?

Ryan Stout
09-30-2014, 10:22 PM
I did it with hptuners via egr position sensor. Works awesome. I'm also using an aem. I'll check my PID here in a sec for ya.

Ryan Stout
09-30-2014, 10:30 PM
So PID.2811 is input from the egr position sensor, yours will be different. Also keep in mind I'm using HPTuners so the string will be different but the math should be the same.

([PID.2811]/.475)+9.5

Adjust them accordingly to get the correct reading. One moves the scale up and down, another adjusts the curve (if you'd look at it like a line graph). Standard its (xxxx/.5)+10 iirc. That'll get you close but I had to tweak mine to get it to jive right. That and I'm picky.

Chrizar
10-01-2014, 08:46 AM
I'd like to wire it to use the a/c pressure sensor, but I'm wondering if I'm getting free air in there messing up the WB reading. With a full Y pipe, and it placed just behind my LT collector on the pass side I would not think it would mess with it.

Since I've got it wired back up I can see my AFR jump around a lot, while cruising and at idle... Jumps from 14.5-15.3 area sitting at lights. I need to run the VE tool to get my tables back in check.

Thanks so much for the help, now I have to go back to the math and understand it. it's been a while since I've used it that in depth.

Would I have to change my flags in the tune for the egr or is that supplied power no matter what?