Thread: Tune for my LS4

Hey guys in October I am getting my GXP tuned in Naperville Illinois at Finish Line Performance I was just wondering if you can tell me what to expect power wise etc... anything will help I just wanna know they say they are the best in the midwest and top 10 in the country. All I have done to the car as of now is just flowmaster 40s and a CAI. Thanks appreciate it.

My uncle had his first gn tuned there and his tta I'll vouch for them but not sure on the ls4