Well I deleted my mufflers a while ago, and it sounds perfect but the other day my little brother and I raced our cars. He has a 370z both cars are automatic. Standing start I always pull ahead and beat him but when we're rolling we're about even, I have the RT base with the skinny tires lol. Now my question is could the muffler delete have caused power loss? Sometimes it feels like I should be able to kill his car, the other thing is can I buy the Challenger wide tires and put them on a 7.5 in wide base wheel? His tires are like 9.5 inch wide so he has a ton of grip.