Hopefully Jon will see this.

i was looking closly at the new def. file i got from Jon last night.

i found a table in there called.

AFR vs RPM for WOT

it was set to 10:1 until 4k then it was set to 13.5:1, i set it to 12.5:1 across the board (just for a quick test) and went for a spin, did lots of WOT runs in diffrent gears ect (almost got a ticket doing this) but my o2 volts no matter what were between 890-950 across the board. i had never seen this table before in my old def. file, and i just noticed it last night.

anyway, what i am wondering is from someone who might have the 8746 hack, or someone who can tell me exactly what the table controls. i find it hard to beleive that getting WOT fueling could be that easy on our cars, but that one change, put all my o2 volts much closer and more consistant that i was ever able to get them my addusting the 100kpa VE stuff.

any insites into this would be great!

Thanks
John

 

the tdf for my 8063 ecm also has that table. I set mine to 12.8:1 across the board untill above 3200, where i set it to 13:1:1. Havnt seen the hack for the 8746 but, correct me if im wrong, i think its pretty much just the commanded AFR in PE that the computer calculates from the VE table and the PE VE adder. The actual AFR will be different if the VE tables are off but if theyre close, then in theory thats what you should get. I tinkered with that as well as the main VE table to get my 02's around .910 volts or so.

 

ok so assuming my 100kpa VE tables are close? how exactly are you tuning your VE tables for for that?

 

so far i havnt touched the VE adder table yet, jsut the main table at map values of 90+ where i have data at WOT. Id like to disable the PE, BLMs, and tune jsut the main table and then do the second VE table so i can get it 'right' but i dont have a WB o2, nor do i know for sure what pph injectors i have, not to mention that the aldl data rate is slow as hell. So Im basically fudging it. Ideally, at some point in the future id like to flow test my injectors and get a WB 02 so i can set it all up the way it should be.

 

yeah, i wanting to get mine close, in january i'm doing a dyno with wb readout, so that should help me out, i'm thinking about getting a wb anyway, just for tuning, and for helping other tune.

 

Yes get a wideband, worth every penny

the ecm assumes that what you have in your main table makes 14.7 to one and then does a calc to figure out how much more fuel would equal whatever it is in your wot table from 14.7

 

i had the PE set at 12.5 with 7747/tunercat. on dyno the actual A/F was 12.2. the dyno operator suggested enrichening to 11.5/1. i enrichened 1/2 point from my prior 12.5 to 12.1 fiquring i would be at 11.7. now the question is why 11.5/1 ? i thought i read a post that between 12-12.5 was best for computer cars? does a specific engine desigh prefer leaner or richer? I understand running rich has some cooling benefits. obvious benefit of leaner is bettter mileage but when in PE that is not a consideration.

 

thats way too rich, you oughta be between 12.7-13.1 or so

 

pablo, i agree that uppers 12's is where the most power is, can anyone else here figure out why from the factory the commanded A/F is 10:1 untill 3200 RPM?

 

that is what i thought. i will reverse off my PE changes in prom.

 

Most likely they are trying to save the cat-con. That much fuel cools it off and puts it out.

RBob.

 

i always heard rich killed cats quickly.