Questions from a ZR-1 newbie

[SharkPilot]

Now that the finances are pretty much ready, I am beginning a search for my first ZR-1. A friend and I test drove one at a local Corvette dealer yesterday and I have a couple of questions.

First, some info about the car:
It's a 1992 model (#302) with 24,000 miles. The car looks really nice with nice black paint and almost no wear showing in the interior. The engine's finish looks good and it is clean (doesn't mean a whole lot, I know). The idle was real smooth and the car drove nicely. No check engine light only a "Low Tire Pres." light was on.

1. Sitting in the car with the engine idling, there was a light knocking sound coming from the engine/clutch/trans area. It was not loud, just noticeable and it varied with engine speed. While driving it was only heard at idle and low engine RPM.
Is that just the dual-mass flywheel or could there be something else going on?

This is the first ZR-1 I have driven and have only riden in one before this so I don't really know what to expect soundwise. All of my Corvette experience is with my Sharks and a couple of C5's.

The vacuum pump only ran for a few seconds before the engine started so from what I have read that is a good thing. Is there any way to verify that the secondaries are actually opening or do you just have to drive it, key 'off' and key 'on', and let the seat of your pants tell you? We only went a couple of miles and I didn't get it above 4000 RPM.

This is getting long so I will stop here. Many thanks in advance for anyone that can give my any advice or pointers.

SharkPilot :steering: