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Re: Computer chip for 1990 200TQ

          The IA method modifies the computer to accept higher than
          stock boost levels as "OK" without shutting down the fool
          delivery system. This allows the protection for over-boost
          to remain, although triggered at a much higher level.
          The IA mod also bumps up the timing (actually reduces the
          amount of retard as a function of boost) and also increases
          the rev limit cutoff point. One actually increases the boost
          (at least in older turbos) by installing a stiffer waste-
          gate spring and/or making the wastegate adjustable and
          cranking up the spring tension. I did both, made the
          wastegate externally adjustable (simple really) and
          installed a stiffer spring that allows about 10 PSI to
          17 PSI adjustable range. I'd like to find an even stiffer
          spring. I typically run at 15 PSI on the street all the time
          and the stiffer "green stripe" spring is very compressed by
          the adjuster at 15 PSI. I want an even stiffer spring so I
          don't have to crank up the tension so much. I think the AI
          mod also increases the timing advance when off boost.