Periodoc

Has anyone tried "Cool Down" coolant additive? I have no overheating problems with Honda radiator fluid and have a Koyo radiator, but plan on HPDE with a normally aspirated 2007 S2K. Trying to cover all the bases. Thanks.

Car Analogy

What makes you think there will be any issues with the stock cooling setup?

zeroptzero

I think that falls under the not needed category. Those additives are best used with straight water in pure racing setups. I haven't used that one but I've used Redline's water wetter additive once in other Hondas, and they are all do the same thing. When used with Honda coolant you may find deposits forming in the cooling system as the by-product falls out of suspension during cool down periods. You don't really hear of S2000's overheating so I would not use it.

Billman250

Definitely do not add anything to Honda type 2 blue coolant.

I had a customer add some coolant additive to his, based on online rumor. It turned to brown sludge.

zeroptzero

^ yup the product creates a brownish jelly like substance when used with Honda coolant which falls out of suspension and clings to the internals of the cooling system and overflow tank etc.