Please no neg comments, i have been searching and reading. Who out there is still running a 40 mm wastgate and running 20+ psi or making over 500 hp closer to 600. I have a s5 street ported motor , af61 turbo, with a new 66 mm wheel,(Thanks to timsturbos.com). ss autochrome 3rd gen manifold, modified for 2nd gen. hks 40mm. I never had any creep problems, maybe 2 psi on real cold mornings but thats about it. Car made 430 whp at 15 psi, the wastegate held the pressure fairly stable at 15 psi. It also held spring pressure just fine at nine psi. I am going for a 25 or higher psi tune, I am putting a 14 psi spring in the wastegate. I also ported the wastegate as much as possible, does any one think i will have a problem. Also wastegate line has always been going to charge pipe.
thank u
john

 

you should be ok but you cant go wrong with a bigger gate

 

also exhaust is a 3.5 inch down pipe to 3inch nid pipe to an apexi dual N1 catback, seems alot of people with boost creep r running 4 in all the way

 

anyone using the 40mm with high power or big turbp application?