Hey not sure if this topic has been covered but I am looking to get a new exhaust system and I was wondering is there any difference between like a pre-made exhuast say made by tom's, apexi and those japenese brands in comparison to hi tech mufflers and other exhuast shops other than price. I was looking at buying a tom's exhuast as it doesn't void warrentee but however they seem to cost a bit more than a custom exhuast system. Will there be any difference in power gains as well?
Thanks
KK