FMS F13 is in!!
car=02 WS6 6sp
jet hot LT's, Mufflex Yw/flowmaster collector, corsa catback with a cutout, TEA stage 2 5.3 heads cut .016, FMS 230 232 591 595 113+2(stock rockers 987 springs and 7.4 hardened pushrods) Shaner S3 Tbody, MTI lid w/K&N, ASP underdrive pulley, Spec 3 with Mcloud Master, a cutdown Pro 5.0, Moser 12 bolt w/richmond 3:90s, random tech torque arm, BMR LCA's, Hotchkis SFC's, Lakewood DS safety loop, home tuning with LS1edit, and some 18x9.5 Chome Z06's....whats your predictions....i made 420 rwhp 396rwtq with the mods above minus wheels, 224 581 112 cam, stock tbody, no cutout, and no real tune also with the hooker ORP not the mufflex.....dynoed again with the wheels cutout and tbody and lost power....A/F is messed up now so i need a new tune.....whats your predictions everyone and should i be alright with the 987s in there with stock rockers spinning to 6700 or so
in hoping with tuning to be in the 420-430 range. my old setup pulled 390, since then ive added my exhaust, the new cam, and will get it tuned.
The 987 spring is a great spring but I think your asking too much of it with that cam. My 987's were maxed with ~.590 lift for my set up based on check install height etc but you have a tad over that. This can probably vary a little from head to head. I don't think the 987 can take that cam without valve float for very long. The ramp rate is just too fast/harsh for the pressure of the 987. I think the 987's will lose pressure within 1,500 miles and start to float because that cam will kill them. It's not a fault with the spring it's just not the spring with that cam application.
The 978 should work as well as other springs like the 921 & Cranes.
Trending Topics
Someone correct me if I'm wrong. Or, call COMP and ask them what to do.
The Best V8 Stories One Small Block at Time
...Again, they're a great spring, but should be changed every 10-15K for safety IMO....Alan recommends the Cranes, which are the springs i'm about to swap in. They will fit the spring pocket where the 987's were...
BTW, "Larry" has a spring tool in the tool section for 25 bucks which makes swapping springs on the car pretty easy...
Kurt you need to get tuned before making an accurate observation on the cam. The FM13 is a TOTALLY different stick than the 224....
josh









