dont have them, but my friend has them. The have insane boost pressure. He had just got the head studs done and blew his head gasket in two days. We are in Denver so the air is pretty thin and he was running 65 to 70 psi boost pressure. The kit is very clean and easy to install. We did it in two and a half hours. I think they are the best way to go but they arnt to cheap. they are probly the highest costing twins out there are costing around six gs.