Preface: down the road, I'm going to do a bunch of mods that are going to require a tune. At the very least, this will include headers, heads, and a cam, along with all of the supporting mods.

As I am very tech-savvy, I am interested in learning to do the tuning myself. I assume that this would be done using LS1 Edit. I am not aware of any other options for tuning an LS1 at home. Are there others?

I have some questions about tuning and about what exactly is accomplished by tuning, and how I can get the best performance out of my car.

First, let me cover what I know, and/or what I think I know, so that we have a starting point.

I understand the difference between a wideband O2 sensor and a standard (narrowband) O2 sensor. I know that my car has stock narrowband O2 sensors, and I am under the impression that there are four of them -- two on each side, one before and one after each catalytic converter.

I am under the impression that the rear pair of sensors are used only to evaluate the performance of the catalytic converters, as part of ODBII emissions monitoring, and that they are not directly involved in closed-loop engine operation. The front pair of sensors, on the other hand, play a major part in determining the injector pulse width to be used in order to maintain an ideal A/F ratio of 14.7:1.

That about sums up my starting point. If I've gotten anything wrong, I'd really appreciate it if someone could clarify. Now, onto the questions.

1. Is the air/fuel ratio measured by mass or by volume?

2. Can the stock narrowband sensors be replaced with wideband sensors? Does anyone do this? If not, why not?

3. Can LS1 Edit make changes on the fly, i.e. while the engine is running?

4. What other questions should I be asking?

Thanks!

 

HP tuners and EFI Live also have user tuners available.
1. MAF Mass Air Flow sensor measures in grams per time.
2. no, You can't just change an imput siganal to the PCM and expect it to understand.
3. no

 

I figured as much. Can you use a tuning app like the ones mentioned to compensate for the changed signal?

 

The stoichiometric "perfect" AF ratio of 14.7:1 is only desireable under light load. Heavier load requires a richer AF ratio to make hp and avoid engine damage due to high exhaust gas temperatures. Best hp at WOT is going to be at around 13:1 or a bit richer for an NA combo. To tune EFI safely and efficiently you need a wide band O2. The Innovate LM1 is a good choice. You cannot replace your O2 sensor with wide band sensors, AFAIK. In any case, it is not needed.

Rich

 

Where do you connect a wideband O2 sensor?

 

no.

 

You just temporarily replace one of the existing sensors or weld (have welded) another bung on (a 10 minute job).

Rich