ZZ Fab head, or larger charger?

Did you loose torque or gain in torque at the lower rpm's for an unmodified head vs. a maxed out set-up? It would be interesting to see the trade off in torque/HP for a head with stock vs. a maxed out head at below 3k rpm's. There more than just making tons of HP/torque at 5k rpm and make no power until that point. Of course thats an extreme situation but its good to know the effects of head porting.
 
He lost torque on the bottom end and moved his dyno curve to the right about 400rpm.
 
It's the same cam he was running before porting, but I don't know what cam it is.
 
It would be interesting to see the dyno curves to do some comparisons. Did the torque perform a lot less in the down low rpm's? When did you actually see the horsepower? To what extent did head get ported to. Sorry for the questions, I just trying to determine how much porting is too much. I had a PDR stage 2 head, that was ported, I just could feel a steady improvement throughout the rpm band. Thats a very mild head porting. Of course it cracked only 50000miles later.:bang
 
COMP461 said:
here are pictures of the extent we are going for air flow

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P1030986.jpg


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Click to expand...


Am i wrong in thinking those are brass/bronze seats?

I thought method got thrown out in the 70's because of longevity and seats dropping.

If i am wrong say so but i personally would worry about it.
 
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