Phil99vette

iTrader: (11)

I dynoed my car and have some weird stuff going on internally. When my Car hits 6100RPM......
1) The power drops off very quickly
2) A vacuum guage goes from pegged @ 0 to fluttering
Phillip

Phil99vette

iTrader: (11)

Valvetrain:
Comp OEM replacement lifters
Comp Chromoly Pushrods 7.30
YT 1.7 Rockers
Comp Dual 987s with titanium retainers
Ferrea Valves

2001 Pewter WS6

iTrader: (43)

What is your cam profile? I have a XE-R 236/240 with the 987 springs as well. From what I am told, anything over 232 duration can go into valve float. I am having Jay from Absolute Speed make me up a set of LS6 heads with Comp Dual 977 springs. The lifters need to be changed to Comp R lifters to handle the spring pressure. Talk to Jay at Absolute Speed about it.

TAHotRada98

ya, just like 2001 pewter WS6 said, it sounds like your hittin the float range. Check, your cam card will tell you what rpm your valve float is.

LOnSLO

iTrader: (15)

Phil99vette

iTrader: (11)

If I go to the Comp R lifters, I need new adjustable rockers......If I got that route I am changing the motor over to forced induction and a smaller cam....
Phillip

Jason99T/A

iTrader: (21)

Phil, I got your PM. Do you have a dyno sheet I could look at?

I would honestly look into a set of Comp 918s or the new Crane dual springs. I would toss those Comp 987s in the trash (call Craig @ GTP, he'll agree with me on this). My personal choice would be the 918s w/ Ti. retainers. A set of Comp R lifters wouldn't be a bad idea either. Keep your lifter preload on the low side with these and you should be good to go. The Comp Rs are not 100% needed. I had no problems turning 7200 with 918s and the TR230 on my GTP Stg 2 hydraulic setup (stock lifters).

Jason