RomRaider

Since the AEM CAI was so inconsistent I went back to my stock airbox and maf scaling. My a-d is pretty good (however, from day to day it will go from 0 correction in a/b to +/-5 or so and back.) I think do to temp and humidity. Anyway, I'm not even getting close to my target afr during boost. Target is around 10.5 (started very rich) and I'm seeing high 11's low 12's in boost. Why would my OL AFR's be off 10%??? I'm going to do some logging to maybe get some help.

Injectors/maf/latency are all stock values. 2002 16bit ecu Set to about 17.5lbs tapering to 13.8lbs Timing is fairly conservative (around 15*BTDC at 2.35 load rising to about 30 at redline.) I'm a bit confused on why the stock maf would be so far off.. Or could I have a mechanical problem? Front o2 is showing 11.36 under boost, but LC-1 shows about 11.6-12.1 under boost...

Is my fuel pump not keeping up?!!


Thanks... again!

Jerod

I think too many people get hung up on "matching AFR's". And stop paying attention to the Front O2 sensor, it's useless for WOT discussion.

If your MAF is scaled correctly (AF Learning A-D stable, sane curve through entire voltage range), it doesn't matter a whole lot. The fueling tables display an "Estimated AFR" whose real-life relationship to realized AFR is wildly variable based on many factors. If adding fuel to the map adds fuel in real life (and vise-versa), you're doing fine.

You will know you are out of fuel pump and/or injector when adding fueling to the table does not correspond with added fuel in real life (realized AFR's).

Well, out of curiosity why was I not knocking at those afr's? And with a LC-1 to close to the turbo, could this throw off the reading to the lean side? The car pulled like a bastard on the log that I posted, richened it up about a half point (fuel followed closely) and pulled not nearly as hard (obviously because it was richer)

also another note, my aflc changes so freaking much with the factory intake, it was damn near zero'd and after doing the logs and then some city driving my C range is 7% D is still 0.

I hate hate hate hate inconsistency... my load was higher while running richer, however boost was dropped about a full point (had to get the factory box wgdc/IAT comp dialed back in)

How do tuners compensate for inconsistency? So if I have it dyno tuned, how do I know its going to be good under all conditions? Is 11.5 afr a good target under boost?

Because you are making too many assumptions. There is no magical AFR where knock disappears or starts, it's a big blend of a lot of variables that lead up to knock events. AFR just happens to be one of the most direct ways we can influence resistance to knock.



AFR and load are not directly related. It would probably take a good-sized change in AFR to make enough of an impact to significantly change load, all other things being equal. Load is of course derived from MAF and RPM, neither of which will change significantly due to small changes in tailpipe AFR.

I don't know what your target afr is, but I would get the LC-1 readings down to about 11 to 11.5.

Depending upon your fuel and timing, you can run leaner, but I think it would be safer to run something richer. Sometimes things change (fuel, etc...) and your AFR D won't respond in time. There are always going to be changes.

You can adjust your MAF scale above 4 V or you can adjust your OL table. Personally, I would adjust the MAF scale but I've seen it done both ways.

BTW, the stock MAF scale on the older WRXs wasn't that great.

Then that jacks up my load. I would have to compensate both timing and fuel for the increased g/s correct? I would need to increase my maf above 4v by at least 5-6% which would bring my loads into the 2.50's and my g/s to around 220-230 area....

Since I would have higher loads what would/should I do with that as far as timing/ol fuel go? Multiply the load values by the increased maf value? Which loads?! 2.0 and above? I don't know where to go with it once I've increased my maf to compensate... Yes the stock MAF scaling does suck and it also is very altered by IAT...

Do you have a friend with an LM-1?

Have you checked the calibration with LM programmer?

No not with an LM-1. I have recalibrated about 3 times since installed 3 weeks ago. Everytime results are the same. However, I contacted innovate tonight and I might have it to close to the turbo (heat causing it to read a bit lean).

I just use romraider to log, should I use the programmer to check while logging with romraider?

Currently, running about 11.5-1 during boost (dropped OL map) and target is around 10.4-1 to reach that....

What should be my steps to correcting my problems? I am moving the LC-1 to the stock rear o2 location Saturday evening and testing, hopefully with some results... if not then apparently I'm running REAL lean and need to make some big corrections.

do you have a walbro? I've tuned many 02-03 WRXs that needed mapped AFRs in the 9's in order to hit high 10's and low 11s AFRs out the tailpipe.

Regarding o2 sensor placement, I haven't seen any leaner readings from going "too close". Just don't put the sensor in front of a catalytic converter...

Have a GSS-342 sitting on my toolbox with the install kit. Trying to weigh if its worth the install or not. Yes factory dips down into the 9's (not sure what their true target is).

I'm at real low 10's to see 11.5-1

One thing that can also make actual AFR's off from targets is LTFT D. Even if it's only a couple percent... that can knock your OL fueling off, this drove me nuts for a while when trying to scale my MAF (until I zeroed them out).. after some driving it would start adding or pulling fuel moving everything around a couple percent. Obviously this isn't going to account for a 10% swing in AFR's.... but it can be part of the issue...

Does your wideband pretty much match your front AFR sensor when in CL and outside of boost? under light throttle you could check and just make sure they both read the same there... usually if your wideband is too far away from the motor it will read slightly richer than what is real... not leaner

D learning is and has almost always been zero. The worst I've ever seen D is .10% So not even a noticeable change. Yes the wideband does a fairly decent job of following the stock 02 in closed loop. It just seems to run so much better a bit leaner. Right now I am around 11.40-11.50 WOT in 2-3-4th gear. 1st is still lean which, is probably going to be. Has anyone installed a 255pump and noticed a bit of richening in the OL curve?

Maybe my wb02 is right on, but I would think I would be knocking running that lean. I haven't had a real good chance to mess with it yesterday or today, but this weekend I will have some time to see what I can get out of it.

Don't assume that your car will begin knocking if you don't run it pig rich. Like I said, many variables influence knock and if the car isn't near currently the knock threshold, simply adding fuel for safety seems like a waste. The stuff is expensive these days, you know

Lean = High EGT's... I don't have an egt gauge, and I don't plan on burning a hole in the top of my piston or burning an exhaust valve because of heat. But at 12.0-1 AFR I do not knock, even with 16* Total Timing at peak torque and a load value of 2.44 g/rev... on stock turbo and intercooler.... According to the spreadsheet with everything scaled (scaled against me, 10 correction and 0 weight added) it produced 261ft-tq at 3850rpms.. Thats pretty damn good considering I was around 240fttq with the exact settings...

And you are aware that excess fueling can also lead to high EGT's, right?

Overly rich has it's own set of problems, be sure to be aware of them.

You're on the right track, good luck bud!