Crazy as it sounds...

Installed a new radiator, who cares the make, its top of the line, and roughly 1.5 x as big. Capacity is 1.5 gallon. I noticed in 70 degree temperature at idle, it idles at 203 degrees. Stock idle is at 220 I thought or higher. So question is, what should I adjust if anything anywhere, to run optimum for daily driving?

Thanks in advance.

 

I believe the thermostat opens somewhere around high 200's, so your's sounds normal. 220 sounds way too high. I've logged my coolant temps with EvoScan at idle and they are usually high 190's to 200's. I have an aluminum Mishimoto radiator, stock thermostat. I don't think you have any issues. If you wanted to have the car run cooler you would need to get a cooler thermostat. Hope this helps.

 

Thermostat opens in the 180-185*F range. Your should be in the 180-199*F range idling around on stock radiator.

After a dyno pull it can climb to 230*F on a regular radiator but with 1/2 size you can be idling 50*F higher and dyno runs 230-250*F or so.