Ah, I see...

 

These two are before the tune, but it doesn't idle much different...



Here's the Dyno vid

 

Sounds more like improper fueling when you stab the throttle. HPT hasn't exactly been known for its comprehensive access to the transient fuel model, and even less so on older vehicles. The original software in my 2006 truck had zero calibratable values in the transient model... If that is indeed the case, a cam swap wouldn't do much for you if anything. Changing the heads to something that the transient fueling is calibrated for would likely be a better solution. Of course that would probably cost you some power. But if you're going to put a blower on it anyway, that might not be a bad route to take.

 

Looking at your dyno I am really surprised you dont carry power higher in the RPM range. That's a big cam. Even with the 4.1" stroke I think its signing off a little early. I mean you more or less hit your peak HP at 6k.

I guess its hard to know how your drivetrain is effecting that though. Maybe the tires make things weird on the dyno as speed climbs.

 

My sentiments exactly

 

I've been doing a lot of reading on the subject and it seems the LS3 heads don't like the bigger cams made for the cathedral port heads. Something about how the intake and exhaust ports don't flow at the same ratio so the valve events have to be reconsidered.

It's all voodoo to me, and to be honest I think I'm going to have to test out cams to see which ones I like better. My setup is not like most - everyone seems to have big cnc heads on their strokers so maybe that's another issue I have to address and bite the bullet to make more powa

 

Its absolutely true. The larger intake port and valve dont carry the same velocity to reversion tends to be a larger issue. They dont need or want as much overlap as a cathedral head does.