FWIW, here is a log I did on my E89 Z4 back in 2015 when it was stock. I did add about 1-2 gals of E85 though. The dyno shop was near 100°f in mid summer in south Florida. Car did limp on the dyno due to access heat, but wastegates remained rather low for the boost and hot ambient weather.
Please note: This should not be used to compare with upgraded twins which require more air and produce more air volume than stock turbos at the same PSI that more likely require more dutycyle under the same conditions and setup.
Thanks.....I followed that original thread quite closely....it is what gave me the incentive to purchase a Z4 lid over the AFE momentum GT airbox. Much cheaper alternative with similar results.