yes , i heard of them all the one's i've seen are very good .
theirs a twin turbo kit for the 350Z with stock everything only running 6psi
HORESPOWER
Stock : 280HP / 244.4WHP
GREDDY : 370HP / 334.2 WHP
TORQUE
Stock : 238.5 FT-LBS
GREDDY : 339.2 FT-LBS
1/4 MILE
Stock : 14.02 @ 101.89 MPH
GREDDY : 12.79 @ 106.53 MPH