There is nothing like a nice lopey idle. The power gain with s4's is awesome and yes on a de/det motor s4 cams is probably THE best cam out there. On only 8psi of boost on a t25 i ran a 13.0 @110mph That trap speed is way way up there compared to without. Gaining 5-6mph is a huge gain. And again this was on street tires as well. I ran on slicks with 12psi and ran a 12.4@110 mph slicks set to 10psi.
The best cams out there period. None of this BC cam comparison crap. These are straight drop them in at 0,0 and run and see and feel the gains. No doubt and ill be using the s4's again on my big turbo det build as well. Should get to my 500whp goal easily especially with the cams.
End of story no need for discussion