Need Some tuning Tips

[Peter 92TSI]

Hey guys, well I finally finished my car tonight, and did some tuning.

Unfortunaly I didn't get my datalogger yet, so all the tune was done by o2s and EGTS.

Anyway here is my setup.

Apexi FMIC
Custom 2.25 inch piping.
16G
550 chip in VPC + AFC
3000 VR-4 fuel pump
560CC injectors
3" Exhaust, 3" cat
15 PSI pump gas

I was doing some third gear pulls and the car was feeling pretty slugish. I had the EGTS around 760C, but the Jumptronix was reading around .84V. I richened it up, and was running ~.86V, but the EGTS seemed to drop to around 730C.

So I leaned it out a whole bunch, and EGTS were climbing into the lower portion of the 800C, but the o2s were around .81V.. Really lean according to the o2s. What the hell. Car did feel pretty quick.


Any ideas?

Peter

[Van]

You know Peter,
Since I've gotten my PocketLogger, I've come to believe that tuning by O2's and EGT's are basically a lie. I can almost smell the flames now, hehe.

With a free flowing "complete" exhaust, my egt's don't climb that high, but I got 26 degrees of timing at 6000 rpm in third gear and my O2's are lower than what the posted "standard" is supposed to be, .86-.88v. Most dsm'rs know that O2's are a variable from sensor to sensor and dsm to dsm. And I've read a couple of "blurbs" (here and there) that most of the racers don't like to push their egt's too high.

I'm thinking that *with the oem ecu,* timing is everything and the egt's are more of a warning/tool than anything, and once you find your individual O2's, based on good timing advance at WOT, then you'll know you are there...

Your egt's will be a little higher if your timing gets pulled. I'd shoot for .86v O2's for now, :) based on your info, until you can see what your timing is doing. Better safe than sorry.

[evil_eagle]

Hey peter, you might have toasted your o2 sensor, have you been running any race gas? I know when I upgraded my injectors from stock to 660cc's and about two days later my o2 went to shit and I could not get any good readings off of it, but it still works enough that it wont set a check engine light. Honestly dude I would go by your egt's more then the o2 readings, I've learned that I cant trust that stupid o2, it's allways a different reading every day..
If the car feals sluggish and your egt's are really low like you say they are then your running too rich, try this dude, flat line the afc and go WOT and if it starts to chug or feal sluggish then lean her up like 5-10% keep going till you cant feal any chugging and watch your egt's.
now if you get to the point where it's not doing it any more then either leave it there or go alittle more, now if it starts to chug again by leaning it more then that sweet spot then your running too lean, listen to your exhause allso, the more richer it is then it will sound deep and fat sounding, now the leaner it is then it will get loud and poppy sounding...
From the looks at your setup with the afc and the injectors you should be fine at 15 psi.
I would trust that egt more then a o2 sensor, I dont even pay any more attention to my o2 since it's dead any way LOL..

[greenstreak]

What are you reading your O2 voltage with? If it is the blue wire mod on the AFC I have seen numerous times when SAFC read about .1 volts (approx.) higher than the actual sensor output.