HeyBrit,i would go for somthing lke 2.5-2.75 inch in bore and a 3-3.5 back box,and just run it straight through from the down pipe and ditch the cat mate.Just have the back box on the end and try to run the system as straight as you can,or even go for a side exit which may be cheaper to do anyway.Andy.
With the mods on your sig I'd have to still say 2.25 if you're going to need some low-mid range power, maybe a 2.5" if you're needing only top end power. 60mm is right between the two if you can find that size. Have you been following the SE-R Cup racing at all? I think most of them are all still using aftermarket exhausts on their cars, althought they also have a hp to weight ratio, which makes more power bad, less power, less weight is best. Is your car going to be run in any official racing series (SCCA, NASA, etc...) , or just hot lapping events?
Yes, I have been following the SE-R cup. I'm going to the race on the 13th at Buttonwillow. For now the car will be just doing hotlapping events. But in a couple years when I actually have a job I'm gonna buy a truck and turn my G into my track bitch and get a liscense and perhaps join the SE-R cup in the SRX class. But that is a couple of years from now. In the near future, S3 cams with the JWT ecu will be in the car. I guess I should have explained all this before I asked the question, sorry. So with the cams, do you still think 2.25-2.5"? Assume I was racing in a different series, say PCTCC.