Stage One for 200tq20v

[Brett Dikeman]

On Sun, 9 Dec 2001, roger wrote:

> Hi,
>
> I am looking for a Stage One wastegate spring and shim set-up for my '91
> 200tq20v.  Do I need one unique to my model?

A better question would be "do I need a spring for my 200q20v" and the
answer is a resounding, emphatic NO.  Approx 270hp is obtained PROPERLY by
a ECU modification involving both pressure sensor and new maps to match
it.  Further HP levels require other things...RS2 manifold, different
turbo, etc.

Unplug the electrical connection to the astegate frequency valve on your
200q20v(its the small valve with three lines running off it, one of which
is a silvery silicone hose to the wastegate) and drive the car.  Notice
how you only get about 1.2-1.3bar?  That's what happens when the ECU goes
into "limp home mode"; it basically stops operating the WGFV. It is
intended to give you sufficient power and acceleration to get the car
home/to get repaired and no more.  This is basically what happens when
there is a serious fault, an overheat condition, etc...or detonation it
can't control(ie, when timing is retarded to the maximum and there's still
pinging.)

If you were to "shim" the existing spring, or change the stock spring, you
would interfere with the ability of the ECU to restrict boost.  1.3 bar
suddenly becomes 1.??? bar.  1.8bar is the max in stock form.  What
happens if your spring or shim results in an ECU totally unable to control
boost, or simply unable to restrict boost to a safe level?

It's all fun and games until some summer you accidentally pump a
tank of 87 octane and jump back on the highway with a hot engine and
floor it.

Which is louder, the sound of the uncontrolled detonation, or $4-6k being
emptied from your bank account?

-B