Probably could be heat soak, but the KKM is kind of restrictive. I put a larger K&N type cone filter and that felt much better. Plus I used a piece of plexi-glass to block off the engine from the filter. I can feel the temperature difference, about 10 degrees. A simply 7.5" x 11" piece with a cut-out for the MAF is all it takes to block off the heat.
