Ok here goes. I have a 4.8 with 63 cai k&n and a superchips programer. I have usually been running in the 15.3s in the quarter. I just changed my oil. Used royal purple 10-30. Also put a new exhaust on and it is a cherrybomb pro 3 in inlet dual 2 1/2 outlet. I ran the quarter mile today at 16.00 . That is a conciderable drop in quarter mile time. It seems that by changing the oil and the exhaust has made me loose power. I dont know why. Rp oil is supposed to be one of the best for power. Cherrybomb is supposed to increase your power. Why have i lost power. It was also a lil warmer today than it was the last time i did the quarter. It is usually about 60 out side when i do it. My Intake air temp was around 85 deg today. Could that be apart of the added power loss. Also i have been told that I can remove my screen in my mass. Is that true and will it help. IF so how do you do it. Please help!!