My guess is 407whp. as long as there is no belt slip. If the IAT's are high I say 389whp.
WARNING: This modification is known to the State of California to cause cancer and birth defects or other reproductive harm due to the extreme G forces once turbo kicks in. ~ Nivo
The rest of my signature is reserved for pointless modification bits like: Halos | window Tint | carbon fiber roundels | short shifter