But bigger is not always better. If you look at Mitsubishi's 4G63 head
design, you'll see that the older heads had larger intake ports, but
the newer heads with slightly smaller ports have a better angle into
the chamber...
What happens is that the larger ports can flow more air, but the air
along the walls of the ports is moving MUCH slower than the air in the
middle of the port, and then when it hits the absurd angle it must
take to get into the chamber, that slows things down even more,
whereas on the smaller ports, the air velocity stays more consistant
throughout the entire airstream, and has a more gradual angle into the
chamber...
Unfortunately, that doesn't really prove a whole lot on it's own, but
the theory is, you want to be able to size the ports so that they are
just big enough to flow the air you want to flow, and still small
enough to flow it with even velocity.
It sounds like you were aware of this and with the timeframe just went
for bigger, which *IS* better than too small ;o)
As for the other... how long is the line and where are you referencing
boost from? Does your fuel pump support the amount of fuel you wanted
to flow that the referenced PSI? What did you use to determine that it
wasn't increasing pressure, a guage, O2 readings, exhaust temps? Do
you have a wideband O2 sensor? (very useful in determining the
rich/lean condition) And are your injectors up to the task you're
giving them? (I've seen people with 2 liter motors pushing 1200cc
injectors to their limits with a well tuned motor and a lot of boost)
I'm definately not an expert on tuning, but those are the things I
would look into... your idea of putting a stronger line on it isn't
bad either, just may or may not be the problem.
--
~Jon
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