I will be needing to get an exhaust made for mk indy with a zzr 1200 engine soon. How do I know weather to have a 4-1 or a 4-2-1, as you can get both as a option for a zzr 1200. I have asked a couple of different people and differmt folk say different things. What is the pros and cons for each. And what sort of price will I be looking at just to get the manifold made. Thanku please 😀

A correctly built 4:2:1 will give you a better spread of torque, a 4:1 is tuned to a specific rpm range but.......

On our little cars you will struggle to find enough room to build the optimum system so in reality it makes little difference 4:2:1 is the best compromise.