That is going up a pretty steep grade from ~1000 ft to ~ 1700 ft through some mountains on the Santa Susana Pass. I was cruising at 3700 rpm (~80 mph) and a Mustang buzzed by. So I nailed up to around 5800-6000 rpm (130 mph) and backed off. It pinged some through that range.
All uphill. The peak of the Pass is about 1600 ft elevation (base of Rocky Peak) and the base of the Pass is around 950 ft (little before Stoney Point)
Normally where I cruise in Simi Valley is around is 700ft. Willow Springs Raceway is 2500 ft elevation. Don't seem to ping there. But I'm wearing a helmet and it's hard to hear.