Eric and Ray ran a month or two ago at Atco Raceway. Each race they were really close. Both running 16.0 or 16.1 and hundreds of seconds between them. I believe the only mods they both had were resonator removal from the exhaust, K&N drop in and the air box removal.

I would like to say that these mods knocked .7 to .8 seconds off the 1/4 mile, but I can't. The weather was a major factor. When I raced Eric it was about 100 degrees and humid and sunny, not a good day for racing. When Eric raced with Ray, it was a much cooler night, around 50 degrees and dry.