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Old 03-27-2020, 12:12 PM   #14 (permalink)
Vman455
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Quote:
Originally Posted by j-c-c View Post
I do see a "lip", which as has been discussed here elsewhere, helps the rear turbulent air behind the vehicle air reattach better to the rear airflow off the trunk lid.

I am not trying to open a semantics discussion, but believe clarity is important here.
A "lip" is a small spoiler. There's no governing body defining "spoiler" with a minimum dimension, and the literature uses the term very generally. For example, Hucho defines rear spoilers as "attached plastic parts made of a soft foam in order to reduce risk of injury, or parts drawn from the body panel" (Hucho, W.H. "Aerodynamic Drag of Passenger Cars." In Aerodynamics of Road Vehicles, 4th ed., W.H. Hucho, ed. [Warrendale: SAE International, 1998], 191). He includes figures that show testing of spoilers from 0-100mm tall, with drag minimum around 20mm (less than an inch)--right around where those Civic spoilers appear to be. He also argues that the purpose of rear spoilers is three-fold:

Quote:
1. Reduce drag.
2. Reduce rear-axle lift.
3. Reduce dirt on the rear surface.
(Ibid.)

Further, the spoiler does not have to be large to have a substantial effect. Hucho provides data for the VW Corrado, one of the first production cars with an active rear spoiler. The difference between these:





...is a reduction in rear-axle lift of 33% at 120 km/h.

I don't see much point in arbitrarily restricting one's definition here, especially in a thread that very generally asked about rear spoilers.
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