Guys...I have my cable made (and it worked on the 1st shot)....and things all loaded up on my laptop...and was able to pull down some "sample" data. ANy experience as to where to start analyzing things to see what can be improved. I dont have chip burner stuff yet so any adjustments would probably jsut be fuel and advance....but any suggestions as to where to start???

 

The big things are your knock counts and blm/o2 readings.

A blm of 128 is dead on for cruising. any number lower indicates a rich condition, and higher than 128 is lean. But I believe anything at WOT(or 70% throttle I believe) or after 3,500 rpm, the ecm automatically sets the blms to 128, in which case you need to look at the O2 readings to get a very rough idea of what your air/fuel ratio is.

Knock counts are good to look at too. It is a way to deturmine if your timing can be advanced or needs to be retarted.

I'm not 100% positive on the numbers at which the ecm automatically sets the blms to 128 though.

 

thanks man...I guess thats atleast something to start with etc.

 

a little clarification.

in PE mode, the computer WILL USE blm data, if it is showing lean. but ingore it, and lock it if it is rich. the BLMs are an indecator for you, you computer should keep you damn close to 14.7:1, but you BLM's and INT's will tell you how far the computer is having to adjust to keep those values.

since teh computer keeps teh AFR at 14.7, why do you need to tune, you may ask.

because if you look closely, you will notice that the WOT stuff for our computers, is a small WOT AFR vs RPM table. basicly the computer assumes its values are correct (locked blms of 128) and then figures how much more fuel it needs to add to the VE values, to reach the commanded AFR for WOT. (from what i can tell, this is how it works... maybe Jon will speak up, as he made the ecu files, and has looked at the code in much more detail that myself.

WOT tuning is hard, the stock o2 is very inaccurate at any value other that 14.7:1, and the further away from taht value you get, the more inacurrate it gets. for WOT, i would look at your knock counts, and try to get the o2 voltage around 900. from there you are going to need either a wide band o2, dragstip, or some accurate way to messure if you are getting faster, or slower. also plug reading will come into play here. really, what it all comes down to, is giving it the fuel it needs to run the fastest. my car may like a 12.3:1 ratio, the next may like a 13.1:1. so you are just going to have to give the car what it wants, and what gets to to the end of the track the fastest.

good luck! after you get the hang of this, you will be hooked on tuning!