> If Ned Ritchie's Stage I kit consists of a stiffer
> wastegate spring and a chip only to prevent fuel-supply
> shutdown, it seems like a cheaper way to go would
> be get just the stiffer spring, and recalibrate the boost
> sensor electronics to increase the shut-down threshold. I'm
> absolutely sure I'm missing something, because greater minds
> than mine have messed with this problem at length (even if one
> assumes that Ned's just a profiteer :-))
> Looking at the Bentley quite carefully yesterday, I couldn't
> figure out how the engine management computer senses manifold
> pressure (no entry for "boost sensor", for one). In the wiring
> diagram, the boost gauge has a wire going to the engine
> management computer, but that's about it. So ... anyone care
> to enlighten me?
First, the pressure transducer is biult right inside the engine
controller. There is a vacuum ( pressure ) hose going right inside
it, and a little module mounted on stilts to the main motherboard.
This module contains the pressure transducer and the associated
signal conditioning op-amp.
Second, if you want to play with the signal, the place to do it
is at pin 1. The output is normalized to 2.5 volts /bar.
"intercepting" the signal and "adjusting" it will reward
you with a substantial increase in boost ( => HP ).
However, YOU HAD BETTER KNOW WHAT YOU ARE DOING.