OK, Cab, I took your math to the next level and came up with this:

.000002857 per mph per inch. So lets look at an 18" extender at 140: 18x140x.000002857 = .0072 quicker ET.

At 200 mph: .010


[img]http://i.imgur.com/boeexFms.jpg[/img]
31 Plymouth Coupe, 392 Hemi, T56 magnum
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