|
Message
Al,Rusty and All,
Excuse my ignorance here, I have absolutely no
knowledge about how ECU's work. I've heard people say that it reads MAP settings
- so what is a MAP, and if it's different because the pressure is different at
different places in the inlet, how can the computer calculate the inlet charge
and timing.
I'm confused!
George ( down under)
I'm working on a new theory about
my low MAP reading. The theory is that this isn't a problem at all, but
rather a difference in the way it's being measured.
What’s new about
this theory? This is what I was telling you a week or two ago.
J
I apologize for
lack of clarity, causing you to have to re-invent this
theory.
Al (Also running
TWM TB)
The TWM TB has a MAP port about 4
inches past the entrance of the TB throat. That means I'm
measuring the air pressure on the suction side of the largest restriction in
the system (from wide open space, to 41mm tube). Since there's no
significant restriction downstream from the TB, I would guess that I
could measure the MAP at the inlet of the side housing, and wouldn't find
it significantly lower than what I'm seeing in the TWM TB. In other
words, I'm measuring the worst possible MAP, which is the suction
side.
From what I understand, the
typical (if there is such a thing) intake has a large TB, feeding into an open
plenum, then into the smaller runners that go to the
engine. If I'm not mistaken, virtually everyone is measuring
their MAP in the open plenum, before the air has to enter the smaller runners
to go to the engine. In other words, the people who are
reading 30" are doing it on the pressure side of the largest
restriction.
I could babble on about this, but
my point is to ask where others are measuring their MAP (turbo folks need not
apply). You'll also have to give a general description of your intake
layout. I already know that Ed and Tracy are using the "typical"
situation. Is anyone measuring MAP in the runner to the
engine?
|