I can honestly say I felt quite a difference with just the upper. I know short runner intakes are better for larger engines, but the car does pull a lot better at the top end. I'm sure it was worth more than .10th/sec. My best time of 13.65 was with the stock upper and I'm waiting for a chance for the weather to clear so I can go to the track and get some updated numbers with my upper and MAF installed.