The 6870 is a true street cars dream turbo. The turbo spools instantly and makes good power. This video below is me driving my Dad's heavyweight GN at the track. Notice how fast it hits 8psi on the transbrake, and running 28psi out the back door with a Dusty spec'd PTC converter. This is a 4 bolt unit with a 1.00A/R exh housing too...