spark tuning and cylinder airmass

[kyphur]

Just curious about how you guys are doing your spark tables. How are you logging the cylinder airmass in g/cyl? Is dynamic cylinder air the same thing?

[WS6FirebirdTA00]

Yes, use dynamic cylinder air.

Spark tables are tricky and there is no easy explanation to it other than put the car on the dyno and find the lowest spark value to use that makes the best power. For example, if at WOT 25º makes 425 hp and 29º makes 427 hp, stick with 25º. Just my opinion.

[kyphur]

Yes, use dynamic cylinder air.

Spark tables are tricky and there is no easy explanation to it other than put the car on the dyno and find the lowest spark value to use that makes the best power. For example, if at WOT 25º makes 425 hp and 29º makes 427 hp, stick with 25º. Just my opinion.

I can understand but I don't have readily available access to a dyno.

I think when I used dynamic cylinder air PID against the tables it was off by a large number. Like one was reading .045 and the other was reading .69 (.045/.69 is a bit of a big difference) so I figured they were referencing something totally different from one another. I will go back and look through it tonight when I get home.

[kyphur]

So is the dynamic cylinder air an accurate source of information to get data from or does it get information from a formula from various sensors that needs to be calculated? Does the MAF need to be tuned and running for it to be correct or does it gather information from the MAP? I guess that's what I'm asking. I don't want to be using it for correct information if that information is not correct yet.

[WS6FirebirdTA00]

You have to have your fueling tables for it to register correctly. That is how it gets your g/cyl.

[kyphur]

Are you talking about just the VE tables or are you including the tabs under the Fuel tab (i.e. General, Cutoff/DFCO, OL&CL, PE, COT, Transient)?

I'm pretty sure I have the majority of stuff under the Fuel tab correct. I'm still dialing in the VE table 100% but I'm pretty much at around 90 - 95% on that now.

How is it using fueling tables to calculate airmass in the cylinder? Not that I'm questioning you, I just would have thought that it derived it from MAF or the MAP since they measure airmass going into the engine.

[vltrb-0]

I can understand but I don't have readily available access to a dyno.

I think when I used dynamic cylinder air PID against the tables it was off by a large number. Like one was reading .045 and the other was reading .69 (.045/.69 is a bit of a big difference) so I figured they were referencing something totally different from one another. I will go back and look through it tonight when I get home.

hard to tell what tables your specifically talking about but the number 0.045 sounds me me like delta cyl air, which is change in g/cyl, if the g/cyl changes too quickly the ecu with pull timing as per your instructions

[WS6FirebirdTA00]

Injector data needs to be correct of course, but also VE and MAF