Diffusers?

[hogwild]

Are diffusers only cosmetic or do they actually do something?

[SUB-ZERO]

Originally Posted by hogwild

Are diffusers only cosmetic or do they actually do something?

I would say that there are those which have been developed using real R&D efforts and actually provide some type of aerodynamic advantage. However, I suspect that many are just for looks and provide little to know advantages; I would say that some may even decrease performance.

-SZ

[SV Concepts III]

Air that passes underneath the car is turbulent and creates a low pressure vacuum underneath the rear end. A diffuser smooths the air flow from the rear of the car which helps maintain downforce at speed. Also by decreasing turbulent air flow, it reduces drag and provides stability.

[SV Concepts]

Originally Posted by Nick@Jlevi SW

Air that passes underneath the car is turbulent and creates a low pressure vacuum underneath the rear end. A diffuser smooths the air flow from the rear of the car which helps maintain downforce at speed. Also by decreasing turbulent air flow, it reduces drag and provides stability.

Absolutely true. Though you did forget to say that on a street car, the effect is minimal. Nonetheless, it's significant at very high speeds. Why else would BMW offer it on the CSL? Why else would there be massive diffusers on all the Le Mans cars

[Swancoat]

There's one diffuser around the boards here that looks pretty damn functional. I think it's VML? It looks like it's about 4 or 5 pieces, covers the whole bottom of the rear bumper and is mucho $$$.

Most of the 'diffusers' on M3post are glorified bumper lips. I think most people get them to help hide the view of the exhaust.

[McLuVan]

Originally Posted by Swancoat

There's one diffuser around the boards here that looks pretty damn functional. I think it's VML? It looks like it's about 4 or 5 pieces, covers the whole bottom of the rear bumper and is mucho $$$.

Most of the 'diffusers' on M3post are glorified bumper lips. I think most people get them to help hide the view of the exhaust.

I think that's VRS(not vorsteiner)

[pepper]

yes there is benefit if using a wind tunnel , and testing

say the quality your looking for is in the range of gemballa ( they have there own wind tunnel and testing equipment )

but yeah, I'm sure most are not tested and will only do harm then benefit