Yes or no to intercooler

How much boost? Under 9 and I would say no but over may require it. It also depend on the size of the turbo. If you are running a small compressor you are running it harder to get your boost and the more air thry need to compress, the hotter that air will be. If you are running a large turbo compressor, it doesn't have to pump as hard to get your boost level amd the charge temp will be lower. Same with a supercharger