Springs and high RPM question....
Thread Starter
7 Second Club
iTrader: (11)
Joined: Jul 2002
Posts: 8,758
Likes: 9
From: Port Tobacco, MD
Springs and high RPM question.... 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
1) The power drops off very quickly
2) A vacuum guage goes from pegged @ 0 to fluttering
Phillip
Thread Starter
7 Second Club
iTrader: (11)
Joined: Jul 2002
Posts: 8,758
Likes: 9
From: Port Tobacco, MD
Re: Springs and high RPM question.... Valvetrain:
Comp OEM replacement lifters
Comp Chromoly Pushrods 7.30
YT 1.7 Rockers
Comp Dual 987s with titanium retainers
Ferrea Valves
Comp OEM replacement lifters
Comp Chromoly Pushrods 7.30
YT 1.7 Rockers
Comp Dual 987s with titanium retainers
Ferrea Valves
Re: Springs and high RPM question.... 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.
Re: Springs and high RPM question....
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.
Thread Starter
7 Second Club
iTrader: (11)
Joined: Jul 2002
Posts: 8,758
Likes: 9
From: Port Tobacco, MD
Re: Springs and high RPM question.... 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
Phillip
I can shift faster than you.
iTrader: (21)
Joined: Nov 2001
Posts: 5,133
Likes: 0
From: Baton Rouge, LA
Re: Springs and high RPM question.... 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
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
