Cambridge 302 Question

I've have a Cambridge 302 in my glider. I have the setting at 0%
since I have the total energy probe fed into it, along with the pitot
tube and static port. The te tube is split just behind the cockpit as
recommended. The static and pitot are split or "t'd" behind the
instrument panel.

When I push hard forward to increase airspeed.....the cambridge VSI
goes up to 10knots positive.

Then when I pull back to bleed off airspeed.....the VSI goes down to
10 knots negative.

The manual says to increase the % , but doesn't say how much.

Another option is to not use the te tube and put it at 100%.

The te probe in my glider is located about 6 feet behind the wing spar
on the top of the fuselage. It's not the conventional spot on the
rudder.

Any thoughts? Recommendations?