Diablosport Forums

Does anyone know where I can get information of how to interpret the REAL TIME DATA in the diablosport?

I drive a 2000 Pontiac T/A and was more concern about the following sections:

Fuel Trims:
What do they tell you? I know that there are two types of trims SHORT TERM and LONG TERM, and LONG TERM is the more important of the two. But what does a positive number mean as opposed to a negative number?
What number tells you if your engine is running lean or Rich? What would the consequences of running rich or lean be, and at what percent should you seek help with adjustments?

O2 sensor readings:
How do you interpret these readings? Low number vs. high numbers.What do they tell you about how your car is performing? Do they show any relationship with the fuel trims?

Sorry I am new to tuning a cars stock programing and would like to know more information before changing any of the parameters to the stock or performance tune in the U7198 Predator.

Thanks in advance!

Fuel Trims --
At normal cruise/driving, the pcm automagically adjusts the fueling to keep the AFR at 14.7. If your fuel trims are POSITIVE, that means you are running LEAN and the pcm is ADDING that much more fuel. If your fuel trims are NEGATIVE, you are running RICH and the pcm is SUBTRACTING that much fuel.

At WOT, the pcm uses the PE (Power Enrichment) table for fueling, not the fuel trims... UNLESS your trims are positive at WOT - then the pcm will add that additional fuel on top of the PE fueling amount. This is why you want to get the trims to lock at 0 or Negative when at WOT, so the additional fuel is not being added.

You want to get your ltft's in the -2 to +2 range. So, for example, if your average ltft's were +5, you would use the Predator to set your injector slope to -5%, and to keep the same amount of fueling at WOT, you would go into the PE setting and change that to +5%.

Anyway, please see my sticky at the top of the Predator GM forum for all the info you'll need...

"LS2/LS7/LS4 - LOGGING & ADJUSTING INJECTOR SLOPE & PE"


O2 Readings --
At normal cruise/driving, they will fluctuate - which is what they're supposed to do. At WOT, they are not very accurate, but can get you close and in a safe range if you don't have a wideband to check your AFR. The higher the number, the richer you are. The lower the number, the leaner you are. At WOT, you want your pre-CAT O2 sensor (bank 1 sensor 1, bank 2 sensor 1) to be in the .88xx to .90xx range.

If your O2 numbers are below this range, you can use the Predator to add more fuel in PE mode, and this will make you richer, thus bringing up the O2 numbers at WOT.

Again, see the sticky linked above...

Thorough and informative once again, thanks Lewis.

There are also parameter definitions on the website.

Thanks