LREYBURN ... can`t speak for others , but when I was racing dirt track , I and the others I ran with , never used a thermostat , but we all used restrictors to slow the coolant flow . It was a trial and error process to find what worked for your engine . Maybe this is why there is some misunderstanding of its use ? I would NEVER run no thermostat and a restrictor for the street
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On the track , a thermostat is one more component that could fail .... at least that`s my story and I`m sticking to it !