Water Wetter (by RedLine) is a electrolytic radiator additive that claims to make water more efficient at carrying away heat. I have indeed used it in my hot-running 93 and it did appear to lower average operating temps 3-5 degrees...ie the width of the temp needle!
It is spoted in the supply racks of most amateur race teams everywhere. It has NO anti-freeze properties or corrosion protection however. A couple bottles should do ya, as a replacement for an equal amount of coolant.
More effective, in order:
a) BURP your motor thoroughly and effectively. Top hose should be full and firm with COOLANT, not air! Surge tank FULL; Facia bottle 1/3 full. If any of the above are incorrect, you will run hot.
b) Ensure radiator CLEANed of bugs, leaves, track rubber, sand, etc.
c) Upgrade your fan / shroud....Yes, even Gen-1 can benefit.
JonB~~~~:<~