The LS1 fitted into our Nissan 350Z now had new heads—Air Flow Research CNC-ported cylinder heads—but we still had to fill in the other half of the equation: our camshaft.
Pair them correctly, and your heads and camshaft can become more than the sum of their parts. Choose poorly, though, and the fancy part on one side of …
With the specs supplied, the cams seem very similar with the exception of lift, so I doubt you see drastic differences between the two.
I'm glad you touched on the potential pitfalls of dyno sim software. You really (I mean really) have to read the user manual from start to finish. Sometimes people just forge ahead and make assumptions, like cam lifter architecture. Many dyno sim software suites make broad brush strokes when it comes to cam ramp rates, and simply assume a ramp speed based on the lifter you choose. It assigns generic ramp rates for hyd flat, solid flat, hyd roller, and solid roller. I've learned it's best to physically enter the actual valve lift for certain resolutions of crank degrees so the software knows your actual ramp rate.
Same goes for head flow. If you just put an assumption of 0-300 cfm, it has to fill in the blanks and doesn't know that you have really good (or really bad) mid-lift flow in the actual heads you're using.
Dyno sims can be as much artwork as the parts selection and engine assembly itself.
Choose the one with the most "chop" brother
The LS9 cam still works good, and it's cheap. It really needs to be in a light-ish car, though, like a Z (as opposed to a pickup). With a turbo, the powerband is quite satisfying, but it's also quite nice N/A (people complain because it likes RPM, instead of breaking axles from a dig). Staying under 400 HP might be a bit difficult, though . . .
In reply to Opti :
True, they're very similar, but two things: the AFR heads are designed for higher lift flow, so the 15% higher lift cam is going to provide a higher average flow with these heads. Also, the higher lift cam has 4 degrees of advance ground in, whereas the lower lift cam has 5 degrees of advance. The 4 degrees of advance means a broader torque curve, higher in the rpm band, which is what they're looking for.
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