Selin/Injector Resize

[Lumpydonut]

I'm new to Nistune and reading up on everything I can find but still can't wrap my head around the Selin translator and K values.

When you resize to bigger injectors it lowers K value, and if you increase MAF size it raises K value so to keep things as close to stock you want to do both. I have a Z32 so I already have the bigger MAF that everyone uses, but I am running the Selin dual MAF currently though my chipped ECU is still set to 1 MAF (Selin set to ADD). I am going to be installing ID1300 injectors which is a fairly large jump from stock, so would it be a good idea to switch my Selin unit over AVG and select "Half value", or "Double Value" for K, or should I leave my Selin how it is and just use the injector resize?

I would think since my large jump in injector size would drop my K value, I would need to double it to keep it close but everything I have found says that on the normal "dual pop" chips they half the values to compensate.

[Matt]

The SELIN converter can either ADD or AVERAGE signal

From my understanding, average simply makes the two MAFs have the output of a single MAF. In this case, there is no change to K in the software from a MAF side of things

I thought it was the ADD mode would be halve the values (meaning double the K constant)

Dont use the resize injector options, adjust K manually and then rescale your TP

Since 370CC to 1300CC injectors is a massive jump, using the option where MAFs report half but you double K constant again would be the best option

[kcolocar]

Would this be the same with the feature pack also? I have a Z32 with 740cc injectors (stock is 370cc) and the Selin on AVG (half the value), so do I both double the K and use injector resizing (total injection multiplier on the feature pack), or let them both cancel out and make small changes to K off the bat? There's not that much info on using the feature pack with a Z32 dual Maf setup, and shops I called haven't messed with the split between the TIM and K.

[Matt]

Adjust only the TIM for injector resize (for example default TIM = 512, which would be halved for 370CC > 740CC injector size)

We used to have to adjust K (which affects TP) to get the fueling changes required (and then move other TP related scales around to suit). Adjusting TIM for injection requires no other changes apart from flattening the fuel map out

Adjust the K constant for MAF load changes where required. If you are using average mode, the ECU sees no change with the MAF compared to single so no K constant change required. If you use an additive I think then K needs to be changed (doubled?) for that. I'm not familiar with how the unit calculates however