Quote:
Originally Posted by Joey@Tick
The cam design on these engines comes from the design of the cylinder head. They are much like an LS3/LS7 head in a way, because they have a large intake port, valve, and a much smaller exhaust port, and valve in comparison. The problem with a tighter LSA is the amount of overlap you get into. The more you have the worse it will drive and in turn the harder it will be to tune for driving and low RPM. Tighter LSA doesn't mean that you will have more low end. LSA is about valve event placement. So when you see a giant Nitrous cam or Blower cam they will have large LSA, as much as 120 in some cases.
As everyone knows wider LSA makes for less overlap and in turn that cuts out some of the cam sound that everyone loves. Cam advance is also used for valve event placement. The sooner you can open the intake valve without hitting the piston, the faster that cylinder will start to fill with air. But in the case of no valve relief on the intake side of these engines, you are limited to where the IVO can start. With bigger lobe duration the more this can become an issue for PTV clearance.
So in all its a balancing act lol. You want valve events that will work with the cylinder head design, you want cam sound, and we want it to be tuneable and driveable. Just don't think a wider LSA is going to hurt you in any way. If you are not that worried about how it's going to drive, you can always go custom if you want more overlap.
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Part of what Joey explained is what I tried to convey earlier in this thread. The referenced TSP cam spec was not yet posted or that you were a road course guy, but honestly that TSP cam spec looks more like it was spec'd for straight line performance than road course, but heck, I'm no expert.