I have a 22 on at the moment which has 4 outlets, been told to use a 25 which come standard on the turbo's, got one it only has 2 outlets!!
Any advice on which way is best to convert 4 in to 2???

 

Hello mate, thats a MC off a ABS car, all you need to do is split each outlet into 2 pipes, ABS cars have these t pieces in the standard piping. Have a look at one at your local breakers (XR3i's with ABS have the same pipework)