Exhaust size - 83 subaru

[Mini_Me]

I am building an offroad buggy out of a 1983 subaru GL wagon. Whilst it is a 4 cylinder boxer engine, each bank has only the one exhaust outlet. the stock car exhaust then also runs a 2 into 1 system, but i'd like to just run a single pipe out of each bank.

What size exhaust, as well as the guage of pipe would i need in order to get good performance out of the buggy, whilst not sounding offensively loud. I would like to get a good boxer note out of it though. This system would invariably need two mufflers. any ideas on cheap mufflers i could source from a wrecker that would suit this exhaust setup would be appreciated.

The engine will be stock, save for the new exhaust and also a custom intake system.

[Resin]

You won't be getting a boxer note with the twin exhaust. I doubt very much that you will be getting the "boxer note" that you hear from an ej20t from an ea81. Running a twin exhaust would be a waste of time. All you'd need is a 2" exhuast, keep the headers unequal length and you'll hear a bit of a boxer burble.