secondaries

The car must be under a load. Get a paper clip and attach it to the secondary diaphragm rod right up against the bottom of the diaphragm housing. Go drive the car and fling her wide open a few times. Come back and take note of how far down the paper clip is. That's a good indicator of how much the secondaries open. Also remember this, if you can FEEL the secondaries open on a VC carburetor, you're not going as fast as you could. The transition should be clean and unidentifiable. You should feel linear acelleration.