Friction Values for RMC Ibox?

I'm thinking of doing a concept for a White Cyclone RMC Conversion. What should I set the friction to?

Set it to 0, 0! Then you should be able to make a 10 mile long RMC! This is in the game or in FVD++?

In-game. I'm just wondering because a steel coaster will have less friction than the wooden style you have to design the track with

Polyurethane on steel has more friction than wooden coasters which use steel on steel. If it were me I'd use whatever seems reasonably close from the steel coasters, Intamin mega maybe with the same number of cars.