2x 15's = 21.
You can calculate the effective thickness of 2 or more same diameter shims in a stack by:
Sqrt(shim1^2 + Shim2^2)
so, sqrt(15^2 + 15^2) or sqrt(450) = 21
Even without the beach or the hill, there is a lot of sand all around town. Would be fun to have some Padla Trax to get a little more bite. If you are not going to be driving a lot on pavement you'd have fun.
I run 37" BFG KR3's at 10psi.... still gotta watch where I stop.
Thermostat is a process control tool. You want your engine at a single operating temp under all conditions. The thermostat adjusts water flow to keep the engine at a set temperature.
Idle, low energy into engine: Thermostat closes to let the engine maintain heat
WFO: max energy input...
yes. They do make restrictor plates you can buy from Summit. 3 or 4 different hole diameters that work with the stock gasket. Or, just pull the guys ot of the thermostat and keep the plate.
Good comments on the pressure topic. My experience is that you can overcome anything with enough fan. If you are counting on natural air flow to cool you are going to end up with challenges.
I think the more you lay it down the less pressure has an effect on the fan efficiency so if you were...
150psi is standard. Tuning with N2 is not the best way. The pressure is really there to manage cavitation. Less pressure = cavitation at slower shaft speeds.