ecu mods--elec. boost controllers

[Ameer Antar]

so what's the actual fuel cutoff point for the MAC 7 or 11? I thought it 
was 1.6 bar, but I've heard other #'s...

anyway, i thought about this a bit more, and some searching, and what I 
thought of is using a bar display driver chip on the ECU pressure sensor. 
Basically I'd have to pull the sensor board off and add a few circuits to 
it. The bar graph display driver is basically a graphical voltmeter. You 
can think of it as an a/d converter. It monitors the pressure sensor 
voltage and displays an turns on up to 10 led drivers to display voltage as 
a number of lit led's. The chips can actually be chained to get finer 
resolution using 30, 40, or more led's. W/ some adjustment I could get the 
2 particular led drivers to turn on at the sensor voltages for 1.4 bar and 
1.8 bar. Using a couple solid-state relays on those 2 led drivers could 
switch the output to the ecu from 3 different sources. In the 0-1.4 bar 
range, the output to ecu would be direct from the pressure sensor [eg. 
0-3.5V]. From 1.4-1.8 bar the ecu would get a regulated voltage which 
corresponds to 1.4 bar [eg. 3.5V]. Then above 1.8, it would get a divided 
voltage from the pressure sensor, making the ecu see 1.54 bar at 1.9 bar 
actual, 1.62 bar at 2 bar, and so on. The stock boost gauge could be kept 
accurate if you just hooked it directly to the pressure sensor output. This 
mod allows for normal operation under 1.4 bar, then the ecu will think the 
pressure is 1.4 throughout the 1.4-1.8 range. Beyond that, the ecu will 
start to see that there is overboost, and eventually cut off the fuel at 
the perceived 1.6 bar. Let me know what you guys think.