manual boost controllers, and ECU functions

[Kaklikian, Gary]

I've got a Greddy Profec B boost controller w/stepper motor on the MC-2
engine in my 4000, which also a custom-programmed ECU and many other
modifications. Yes, the boost ramps up much quicker and more consistently
than with the stock wgfv.  If I set high boost to 15psi, then I get 15psi
consistently in the higher gears (but a few psi less in 1st and 2nd since
the engine load is insufficient).  The wastegate spring limits the boost
range selectable from the Profec. With a stiff spring, e.g. 1.8 bar, the low
boost level cannot be set less ~12psi, but the high boost can be set >23psi.
How do I know? I accidentally turned the high boost level to about the
4'clock position once, the boost hit 23psi, and the turbo (K26 Sport) blew.
Lesson from this - use the stock wg spring, which allows a max boost of ~19
psi,  be careful with the knobs (ECU safeguards are overriden),  and use the
best bypass valve (eg plunger-type) that you can find. I won't run over
15psi anyway at this altitude (6000ft) unless I'm using race fuel and
conditions are ideal otherwise. (At sea level, boost levels increase by 2-3
psi with the same settings on the Profec.)