2018 ZL1 LT4 with BTR Stage 3 will not open throttle past 50% and then closes
I have calibrated many LT1 vehicles and trucks with camshafts but never an LT4. I recently got the car up and running, idling and driving well enough for a starting calibration. I had time today to get the car on the dyno and was planning for some quick pulls to wot dialed in, unfortunately the car has other plans. Normally with a stock camshaft, I see the boost and torque come on strong, throttle close a bit in mid rpm peak torque and then be fine on the top end. I have a procedure for dealing with the torque and keeping the throttle open. This Stage 3 camshaft car from the beginning of a pull at 1500-2000 rpms opens the throttle slow to only about 35% makes 3-4 pounds of boost and then slowly closes the throttle down. I can pull the car up to 5,000 and it will be pulling a vacuum on the top end because the commanded throttle is 20%. I have played with everything, and the car is 9 pulls on the dyno in with the only real change in performance being the throttle now opens to 50% and then quickly closes down to 20%. I don't know if its frustration or a holiday weekend but I'm missing something. I didn't think the camshaft would make that big of an impact on the torque calculations that low in rpm, but the throttle is running off torque as its closing down. If someone could look over the torque log and tune it would be much appreciated as I'm missing it.
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