Rear diffusers: Another new trend?

[TiG]

I've been again noticing trends in the recent models of cars, and this time its the rear diffusers, The New 08 Clio model has new rear diffuser setups, as well as the 08 308 Pug.

Wierdly enough whether they are actually any use of reducing drag/improving downforce on cars of this type on normal road conditions i'm not sure about. But Aestetically they actually do a lot for the looks in my opinion.

Again to me, this addition of obvious rear diffusers has really started to pick up on models across the car ranges, not limited to things like the Civic TypeR etc.

Is this being filtered in from racing experience or are designers finding that its winning business as a feature to have?

TiG

[sleepyhead]

Simple answer is, it gives it that "racing edge" feel which will attract the punters...much like the "spoilers" did back in the 90s.

I, for one, would like a proper rear diffuser along with doing the whole under car aero package...just needa wind tunnel to test it all on (highly unlikely).

Give it a couple of years and it'll be carbon front splitters with canards/winglets to give it that "edgy" look.

[Vimeous]

Doncha just love 'em?

While they are a racing development very few road cars will ever use them properly making most a styling add-on. I think they're great.

XJ220 had a pair of huge venturi tunnels if my memory serves but it's not exactly a Clio 197

[schmunk]

Wierdly enough whether they are actually any use of reducing drag/improving downforce on cars of this type on normal road conditions i'm not sure about. But Aestetically they actually do a lot for the looks in my opinion.

I would have thought that the high ground clearance of most normal road cars would make the pressure drop underneath the car too insignificant to warrant any diffusing back to ambient, so therefore it is almost entirely cosmetic.

I am happy to be proven wrong, though.

[Butuz]

Diffusers do work on cars that are 0.5 inches high - they don't work on renault clios that are 10" high.

Butuz

[kalniel]

Diffusing in terms of trying to create a pressure drop and therefore downforce is pointless on a road car, but managing the airflow around the rear of the car to reduce drag caused by turbulence might be worthwhile in terms of fuel economy.

[Zak33]

most are for looks (95 example)

some work.... Vimeous, as ever on the money.....Jag XJ220

[Vimeous]

XJ220
Clio 197

Somewhat different methinks!

[Neo_VR]

I remember seeing a documentary somewhere about the Clio 197... the Diffuser does actually have a mesureable benifit, as does not having a spoiler.. because the designers were saying they were under pressure from marketing to fit spoliers and twin chrome zorsts..

Most cars have aerodynamic packages underneath now... the Mazda 3MPS does to help with high speed stability.. most modern cars have undertrays too.

[SilentDeath]

is the xj220 picture supposed to look like a pair of aero-dynamic testicles?

[BenW]

The clio diffuser is meant to create 40kg of downforce IIRC, quite a reasonable amount IMO

[kalniel]

The clio diffuser is meant to create 40kg of downforce IIRC, quite a reasonable amount IMO

At what speed?

[Barakka]

At what speed?

[Dr.Evil Voice]One miiiillllion miles an hour[/Dr.Evil Voice]

[Butuz]

The clio diffuser is meant to create 40kg of downforce IIRC, quite a reasonable amount IMO

*falls off chair laughing*

More like 4kg

Butuz

[badass]

The clio diffuser is meant to create 40kg of downforce IIRC, quite a reasonable amount IMO

Do you think the rear bumber mountings can handle 40KG pulling on them?

[Neo_VR]

according to AutoExpress:

The changes aren't only for visual impact. That diffuser really works, and can add up to 70kg of downforce. The Renault engineers haven't only focused on the things you can see, either. From the specially created double-axis strut front suspension, designed to eliminate torque steer, to the hidden twin exhaust tailpipes - tucked away so they don't counteract the diffuser's effect - the 197 is full of evidence that the team behind it was truly passionate.