Ford Focus Forum, Ford Focus ST Forum - View Single Post - 1/4 mile not making sense?? Help!
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Old 08-04-2011, 03:51 PM   #46
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I'm talking street tires though.
Slicks I can completely understand, being the grip ratio is far far far superior to crappy streets.

But the point I was getting at is that even though the smaller tire lets you RPM up faster (which is what a lower gear ratio is designed to do), you are still falling to the same RPM during shifts.
If you look at how far, in feet, you traveled, even with RPMing up slower you're still going further.

So the only explanation I can fathom is that rotational weight plays a huge part. Being a taller tire weighs more it takes that much more power at speed to turn it, which effectively lowers your power output, a parasitic loss basically.
So if you could find a taller tire that is the same weight (or lighter) then my figures should be true.

And I know there's a ton of real world stuff missing from the math. I'm just trying to understand why the math isn't even close to your guy's real world experience.
Don't "think outside the box".
There is no box.
Do it correct, or do it twice.
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