XFI Individual cylinder tuning

[NY Twin Turbo]

Does anybody think it would be a better strategy to base percentage of correction on map instead of RPM?

Long ago I was able to tune my individual exhaust gas temps within only a few degrees of one another. Under moderate to heavy load points it's very consistent. It's this area of the map that is most important to me anyway. I don't see a lot of variation beyond the 7 degree increments the XFI reads temperature in. I always correct +/- against the cylinders that are naturally the same or the one that's in the mid temperature rage. No one could ask for closer numbers. It's beautiful.

However, The lighter load points can be a little all over the place. 50-100 degree differences is not uncommon. I'm not going to chase the perfect EGT temps forever. Just making an observation, because the RPMs are the same. It's obviously the MAP that's different.

 

[Mike Licht]

A 2D table with MAP and RPM would be best,

 

[NY Twin Turbo]

A 2D table with MAP and RPM would be best,

Well, that would kinda be a 3d table wouldn't it? I don't want to get greedy.

Just saying, I think the length of the commanded pulse width is more related to load (MAP) than RPM. So the correction should reflect that. No?

 

[HighPSI]

An even better idea would be Individual fuel maps, but 99% of the people couldn't take advantage of it. I tune on several cars with at least 9 WBO2's (1/cyl & XFI), and have managed to get the individual cylinder fueling pretty much dead on. They don't change their boost from pass to pass so MAP I/C correction wasn't really needed

 

[NY Twin Turbo]

An even better idea would be Individual fuel maps, but 99% of the people couldn't take advantage of it. I tune on several cars with at least 9 WBO2's (1/cyl & XFI), and have managed to get the individual cylinder fueling pretty much dead on. They don't change their boost from pass to pass so MAP I/C correction wasn't really needed

I'm obviously not using 6 wide bands. That would be cool! Although, I wondered if accuracy is a concern when using WBO2 sensors in such a high pressure environment like the primaries before the turbo?

I am using individual EGT probes. I shoot for dead-on temps. And like I stated earlier......I've gotten it nearly perfect. But only when it's under moderate to heavy load. It's impossible to nail it under all driving conditions. I guess this is as good as it gets. As long as it's good where it counts.

By the way, for those of you who don't monitor individual EGT's, um, you may be surprised to find there could be some pretty scary differences.