Hey guys I'm going to go get my s4 nonturbo tuned with a standalone on Wednesday, and I'm wondering what effect changing leading/trailing split will be on power. Would increasing or decreasing the split give me more power? I know some people run negative split (is that when the trailings fire first or something?), which seems weird to me. Would that have any benefits on my application? The reason I'm asking is that the place tuning it has limited experience with rotaries (but they have a dyno, they know how to use the EMS, and the price is right) and may not know anything about tuning ignition split.

 

From what I have seen, no, it's not going to significantly effect power. The Megasquirt ECU forum FAQ page has the stock split table, so start there.

Negative split can't be good due to the absolutely tiny trailing plug hole. Seems like there would be no advantage.

 

Why are you asking us???

Get the car on a dyno and go figure it out yourself?


-Ted