[s-cars] Wastegate Spring - long, boring

[Richard Tanimura]

I have been trying to get my head around the
relationship of the WG spring to ECU boost. I have
read, thought and tested. Beware, I am often wrong.

The WG spring determines "baseline" boost. This is the
boost you can get when the WGFV is completely open.
The most instructive picture available is on Scott
Mockrey's site. It say's it all. It is easy to see
that compressing the WG spring will a) increase
baseline boost and b) give less WG creep at any
pressure. This is all completely independent of the
ECU and programs.

With OEM chips, the WGFV is normally not regulated
below 30% throttle (IIRC). So under 30% throttle, you
are solely in the domain of the WG spring. Some custom
chips will alter that threshold. Mihnea will if you
ask for it.