Idle overspeed and underspeed???

[InandOutPerfromance]

Sorry if i have missed this somewhere. But is there a equivalent. Tuning a 04 cobra with mild cams and wanting to exaggerate them!!!

[daniel302]

The proportional gain under the spark tab is similar to the overspeed/underspeed of the LS cars. It's how fast the eec will advance/retard spark to maintain desired idle speed. So much is really gonna depend on the cam profile and how much overlap there is, though. I'll have to look at one of the 03/04 cobra reads I have when I get back to my laptop with HPT. I think FGBIO uses some variation of an idle spark table as well, but can't recall for sure. Anyway, the usual things will help exaggerate them- a nice open exhaust, back the idle speed down, drop the prop gain if spark is jumping all over the place, and lower the min idle spark. For cams with any significant amount of overlap, I force open loop at idle as it gives better control of fueling with high overlap. With open loop idle, you can lean it out to make the cams sound more pronounced too. FWIW, in one of the tunes I wrote for my car, I used the BKT and MBT tables to limit spark in the idle area to around 15 degrees. That, coupled with leaning it out a bit in the idle region, lowering the prop gain and min idle spark, the little cams I have were chopping hard, but off idle drivability and vacuum suffered (it's a kenne bell car with the standard bypass valve and I was barely pulling enough to open it at idle)