I was talking to another 93 Speed density member and he told me about tuning the VE tables using the INT values.

Instead of using the standard VE equation:

Change in VE = (1/2(BLM1+BLM2)) / 128
New VE Value = Change in VE * Old VE Value

He would lock the MIN & MAX range for the BLM values to 128. This way it forces the INT to go from 0-255 with out incrementing or decrementing the BLM values. By doing this you can then tune the VE table by using the same equation:

Change in VE = (1/2(INT1+INT2)) / 128
New VE Value = Change in VE * Old VE Value

I assume if you try to tune using the INT values while the BLM's are locked at 128 you have to have a VE table that is near perfect or else you will peg the extreme high or lows without enough room for the ECM to compensate.

Has anyone tuned their VE tables using this method and how accurate is it? Thanks!

 

I tune by INT exclusively on my car. I only unlock the BLM when I think I am very close to 128/128, which I usually am.

It takes a lot of playing by the "factor" is finer than a simple "coarse BLM" calc. Especially, when you are say 10-15 +/- from 128. The factor is affected by your other parameters, so you need to play a little before you get a good adjustment factor.

Lastly, remember that SD cars are affected by the Intake Temperature, especially if its relocated. You need to get the MAT calibration "tight" first.

Though the concepts of the 93 SD system is similar to the 90-92 F-body system, the exact "numbers" are different and no directly transferrable.

 

Glen-

Do you just keep editing the VE tables until your INT's are dead on at 128? I wrote a small program that collects the data logs (MAP, RPM, Fuel Cell, INT1 & INT2) and takes a average of the VE using the MAP & RPM value using the INT values. DO you know which cases I should exclude from my logs? (WOT?)

BTW- What do you mean by MAT?

 

MAT is the Manifold Air Temperature sensor. It is called IAT on 4th Gens I believe, but it's the same thing.