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Re: Extrude Hone

  Throttle-body injection is just that; the fuel is injected in the
  vicinity of the throttle body, well upstream of the intake manifold
  runners to each of the cylinders. Port, or multiport fuel injection
  injects fuel in the vicinity of the intake port in the head, or in each
  of the individual runners of the intake manifold just ahead of the intake
  port/valve. Multiport injection has the advantage of the possibility
  controlling mixture on a cylinder-by-cylinder basis where throttle-body
  injection cannot. Intake manifolds for throttle-body injection are called
  "wet" 'cause the fuel/air mixture flows through them to the head.
  Port-injection intake manifolds are called "dry" because only air flows
  through the manifold up to the point that the fuel is injected near the
  intake valve/port or inside the port in the head. Design criteria is
  different for wet and dry manifolds because you want to maintain the fuel
  in suspension and with even distribution in a wet manifold. There are
  variations on this theme, you could have multiple throttlebody injectors
  and throttle bodies for each cylinder, this would be multi-throttlebody
  injection and the manifold would be wet and would still have the
  possibility of individual cylinder mixture control.