Re: Simple-minded turbocharger ruminations ...

[Alan Cordeiro <cordeiro@avlna.com>]

> 	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?
> 
> 	-Arun
> 

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.

Alan Cordeiro