Standard exhaust manifold, I do have a 4-1 but they are shit so going to get a cheap 4-2-1. That's all it has atm is a filter, inlet and cat back. I am hoping to get some cam pulleys and fit my lightweight flywheel and crank pulley :-) I doubt I'll see anything more than 180-185 brake but it's just a bit of fun :-) Rob.