When I dyno'd my car it was the same kind of setup with the bonnet down, and due to the way the 350z intake works, its not a fair test with a popcharger. I had heat soak and temps were higher than standard, but I still got 240WHP (280BHP). So while heat soak is an issue, you still should have hit good numbers. Think about all the guys in the US, their intake temps on a normal day are as high as ours on a really really hot day over here, so it must be able to make those numbers in the heat too.