Re: Boost in a teapot.

[zm@mhcnet.att.com (Zafer Mehmood [209])]

All this discussion about overboost, computer mods, etc has popped several
questions in my mind that I hope someone can answer:

How does the amount of boost affect the operation of the computer?
>From Bill's excellent description, it is clear the computer controls
the amount of boost via the frequency valve and wastegate. But besides
this, does the computer need to change its output (ignition advance/retard,
and fuel injection) based on the level of boost? Glen mentioned something
about the IA stage II mods changing the timing based on boost.

What is a "Boost Map"? Is this the standard ignition/fuel injection
parameter map stored in the PROM altered with new values as a function of
(increased) boost?

The reasons for my questions are to understand what happens when you
mechanically or electronically fool the computer into allowing more boost.
Besides the obvious danger of damaging the engine due to uncontrolled boost,
or reducing the life expectancy of the engine, I would like to know if there
are other hidden side-effects if the computer needs to alter the operating
parameters based on increased boost but isn't.

Zafer


-----------------------------------------------------------------
Zafer Mehmood				   AT&T Bell Laboratories
zm@mhcnet.att.com			   Murray Hill, NJ