Last little pull that I did in my backyard had some pretty good knock. 10 degrees. It had been showing about 4.5 degrees, but this last run was A LOT ! Engine is all forged 5.3 with a Whipple, open exhaust---about 40" past the exhaust manifolds with 11" dirt track mufflers. Wideband was showing about 2% rich in that area. Runs great, but I would like to get rid of that knock if it is real. The exhaust isn't hitting anything, but it is dam noisy.
I richened up the 112 kpa cell that shows 11% lean---blip in the VE table. Fuel pressure is increasing with boost.
Any ideas? Thanks