84FSP

iTrader: (3)

Hi All,

Curious to hear input from the pro's on upgrading to a bigger cam while maintaining PTV clearance. I have done a fair amount of research but am still hung up on how to use the split duration to manage a more aggressive cam while staying safe on PTV clearance. It seems like there is some art to managing PTV by selecting the cam with the right split duration and LSA offset. I'll be ringing up one of the Cam pros like Cam Motion, Howards, etc but wanted to be a bit smarter before I did. In addition to the lumpier cam I'll be adding a Fast intake, Not convinced if I get the 92 or a 102. I hear the 102 runners are superior even if you run the 90mm tbody with an adapter.

I had gone mild on the cam fearing PTV issues but had lots of room to play with after doing the clay measurement with the solid lifter to check. I have the clearance numbers but have to track them down. From memory they were 3X the required whcih led me to believe I had some room to play.

I'm hunting the mythical sub 500 whp. I'm tolerant of cranky under 2K rpm behavior but do want solid HP in the mid band.

The current setup wasn't well matched but put down 427HP on a very stingy Mustang Dyno. It does have a really nice power under the curve in general. Unfortunately, it really ran out of steam at 5700 which is probably a combo of intake and cam.

Current setup
L76 (G8 6.0) converted back to LS2 with all the DOD garbage removed
2.5 dual setup with 1 3/4 headers
Thompson 235CC P&P heads with 63cc chambers, PAC1219 dual valve springs, TI retainers, LS7 Lifters, Comp Cam Trunion upgraded oe rockers
Ported Dornan LS2 Intake (soon to be replaced with a Fast)
~11.5:1 compression via 0.40 head gaskets
42LB injectors - running 80% duty cycle so may need to go a bit bigger
Howards Cam - 3 bolt - 112LSA 226/232 with 578/587 lift


I'm most curious to understand how offsetting duration and LSA can allow bigger lift without significant impact to PTV numbers. I'm not adverse to a custom grind but have to assume one of the million cams out there is a better fit for my setup.