1989GTA

Here is my latest dyno pull. It was done on a Mustang dyno. Engine mods are as follows. Texas Speed VVT-3 camshaft. CNC ported L92 cylinder heads with upgraded springs but stock valves and rocker arms. LS3 intake manifold. Home made cold air intake. Hand ported LS3 throttle body. 1 3/4" x 1 7/8" stepped headers. Full 3" dual exhaust with X-pipe. 6L80 transmission with a Yank SS3200 converter(unlocked). In hind sight I wish I would have had the LS3 intake valves installed. We were starting to get valve float around 6600rpm and had to terminate the pull. Here is the graph.

hrcslam

Very nice numbers! I would'nt replace the valves, but go with a stiffer spring and make sure your pushrods are up to the task!

KCS

iTrader: (20)

What springs?

1989GTA

The springs came as part of the CNC head upgrade by Texas Speed. They are rated at .650" lift and 144/425.

Ryne @ CMS

iTrader: (10)

personally i would run a lighter ls3 valve, and keep a lighter spring on the car... once you start getting into the low to mid 400's in open pressure, the cam phaser starts to act up.

1989GTA

Ryne, installing a 427 short block and getting rid of the VVT. Hopefully I will be out to your place for the new tune in November. Also hopefully the old tune is good enough to drive the car with.

Ryne @ CMS

iTrader: (10)

just bring me the pcm and i will make some edits to the file to help you get it here

KCS

iTrader: (20)

That's what I was wanting to know. I'm using VVT in my next build so I'm curious what the phaser can withstand. I have a set of Comp's new conical springs which are 410lbs open, so I guess they'll be okay.

Ryne @ CMS

iTrader: (10)

you should be good with that... personally i really like the PSI 1511 beehive springs for this setup... you just need to run a controllable lobe and be realistic with the lift.

1989GTA

I think I will do that. Thanks.

KCS

iTrader: (20)

Thanks for the advice.