Re: Wastegate Port / Control

[Dan Bocek <dan@di.com>]

> I see a vacuum port to the upper side of the wastegate on my TQC.
> It is open to the atmosphere.  The car runns great.  Should there
> be a hose to this port?  If it is unused, it offers an alternative
> to wastegate springs as a boost controling mechanism.  A fertile
> mind could easily do control via manifold pressure modulation.
> I know some OEM applications that do electronic boost control via
> this method.

It is supposed to just be open to the atmosphere, but you are correct in 
your thought of it's use as an alternative to a stiffer spring - I've 
been using just such an implementation for the past few years.  The big 
advantage of putting some manifold pressure into that normally open port 
is that you can make your boost pressure adjustable from the cockpit - 
pretty cool setup, and works great (plus an air bleed valve is a bit 
cheaper than a new spring from Ned).

                                                         Dan Bocek
                                                         dan@di.com