Thread: Toyota GR Yaris
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Old 05-09-2020, 10:08 PM   #274
Irace86.2.0
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Quote:
Originally Posted by why? View Post
the wrc version has a massive restrictor. They made it 3 mm bigger and it added 70 hp. Unrestricted it could put out stupid power.
Just fyi, that 3mm is a lot, but I get your point. When looking at laminar flow, the flow rate is proportional to the radius to the 4th power, meaning a 3mm change from 33mm to 36mm can be big. As it is, 36mm is a 9% improvement over 33mm, but with the ^4 there is a 42% increase in flow.

This makes more sense when we look at the area of the pipe, which without the laminar flow dynamics discussed above, we see 3mm results in a decent bump in the opening:

{[pi(36mm^2) - pi(33mm^2)] / pi(33mm^2)} x 100 = 19% increase
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