Evans NPG is a coolant, used in place of 50/50 blends of water/ethylene glycol. Evans owns the patent on "reverse cooling", and forced GM to stop using it after the LT1.

The basis of the system design is a significantly higher coolant operating temperature, which increases the thermal efficiency of the engine. While doing this with "conventional" ethylene glycol based coolants will typically lead to detonation problems, the Evans coolant claims to eliminate the hot spots that cause the detonation by its effects on nucleate boiling. At about that point, it goes over my head.

The original NPG typically requires significant modifications to the cooling system, including a custom designed radiator.

http://eee.evanscooling.com/index2.html

 

Water wetter and the royal purple one where both created to be used with straight water. The reason being is that most drastrips do not allow anti-freeze because if it leaks it soaks into the rubber on the track. This becomes a problem because you must then scrape the track clean. This job sucks horribly by hand, thats why NHRA says no antifreeze... water wetter is fine though.

 

use only DISTILLED not tap water and water wetter it works