The additive I bought for my foams Rich is exactly the same as the additive used on Off-Road Tyres - NOSRAM Traction Additive Carpet. But late time I raced 'nites' told me no additive so I ran without it. I found running Contact RC SE foams allowed me to run reasonably ok better than I raced on Mini Pins. So the solution to inconsistent grip levels would seem to be a simple one, get the carpet shampooed clean then ban all additives.
