Hey, I was wondering on my 1987 rx7 that I am doing a S5 Turbo II swap in. I got rid of the the heat and ac in my car. So on the driver side of the rotary engine there is a coolant hose that goes to the heater core. Can I just plug that off or what can I do with it. I will not need that because I took out the heater core?.

 

You could just cap it if you wanted to... since you already took out your heater core. Looking at the coolant flow diagrams, you're not disrupting anything by just blocking it off. That nipple normally goes to the firewall on the drivers side, through the heater core, out the passenger side firewall, and back to the nipple on the bottom of the radiator.

If you cap the nipple on the block, make sure you cap the one on the rad too. Or, if you're really afraid of coolant leaks, run a hose from one to the other.