Ok when i first became a JSB I bought evo valves, springs and retainers, then later got another set sold them and now yet another. One change since then and now the crower 272's are gone and BC 280's have been put in the pile of boxes.
A local buddy of mine bought an replaced his stock evo stuff for a set of the ti retainers and springs. The machine shop tested the old ones and only saw like a 3 lbs increase on spring pressures. This and he went to a non beehive and the ti retainers which are heavier and don't stand up to RPM's like the beehives. Now for those that don't know the factory evo retainers are micro grams its scary how light they are.
I'm not selling my springs and retainers for a 3 lbs increase thats why they sell shims. I've been reading around and lots of places say 95 lbs closed on the seats for there builds where 65lb per hour turbos at 30psi plus are used. Just wondering what others on here are running for closed and full open seat pressures and is anyone else running the 280's that can give me an idea of max power in RPM's still need to call Jeff for chip expertise and need an RPM rev limit. Not that Jeff doesn't know just wondering now.
But I did see that FP sells beehives without retainers for 220 they say it increases RPM limit from 8K to 10K.
and GSC has them for 215 and have these specs
* Spring Pressures: Seat @ 1.56"=68 lbs
* .625"= Coilbind.
There set with retainers and chrome moly seats takes the RPM's to 12K which is just shiming...Discussion below.