How much downforce does the 197 diffuser give?

[Marv-C]

I have read in articles that the rear diffuser on a 197 actually works (unlike the fashion statements that everyone else is putting on their cars :dapprove::dapprove and am curious if anyone has some facts on it.

Just for the pub conversation of course:rasp:

 

[powey]

Its close to 20G through the twisties

 

[Tom]

40KG at 70mph apparently.

 

[Marv-C]

40KG at 70mph apparently.

That is a lot

IIRC,the whale tail on an escort cossie only produced 20KG.

 

[Steve]

On track it really is planted.

 

[famguy]

thats what i love about the 197/200 all the fancy bits are there cos they increase the performance of the car, not just for show

 

[MikeLYR27]

40KG at 70mph apparently.

Is it? I always thought it was 40kg flat out? Prob wrong tho lol!

 

[Peperami]

Twelvety.

 

[Poopensharten]

They drive upside down in tunnels IIRC TBQFH

 

[DIDITNO]

its 40 kg at 70mph, up to 70kg over that speed, so you dont have to have a spoiler apparently

 

[Tom@JMS]

20-40... Both impressive for a part commonly seen for styling only!

 

[Marv-C]

its 40 kg at 70mph, up to 70kg over that speed, so you dont have to have a spoiler apparently

I love my car even more now:approve:

 

[jayxx83]

indeed it is impressive. hate these mockery you see on VXR corsas and the like

 

[MikeLYR27]

Wow 70kg is very impressive! Yeah all the fake ones make me laugh, the corsa one looks awful. Does the focus RS diff do the same job or is that another useless one lol!

 

[famguy]

apparantly the front wing in the 200s grille also channels air to the rear arches and to the rear diffuser to give it even more downforce

 

[Gaz_]

Cant see it myself tbh, i'm sure it needs a flat undertray to keep the airflow clean........ it looks mint though

 

[p4cks]

^ 100% correct.

Same with rear spoilers on FWD cars - just for show.

 

[Tom]

^ 100% wrong.

[FONT=Verdana, Arial, Helvetica, sans-serif][FONT=Verdana, Arial, Helvetica, sans-serif]The downforce generated by the diffuser means there is no need for a rear spoiler [/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]to counter the phenomenon of lift. For optimal stability, the system reduces lift by a factor of three and produces the equivalent of 40kg of rear downforce at very high speeds without (on track) detracting from the car's carefully honed aerodynamics designed to achieve a low CdA.[/FONT][/FONT]

It might be a small amount, but its functional.

 

[richard1]

So would a 200 have less downforce?

As the pipes now take up space in the two outer parts of the diffuser? Must have an effect....

 

[Gaz_]

If you hung 40kgs off the back bumper it would fall off, especially being a Renault. Its only clipped in with, iirc a few of 10mms near the rear beam

Think about it

 

[p4cks]

'very high speeds' meaning what? hmm.

 

[Tom]

No idea, ask Renault.

Its in the press documentation. Thats all i'm quoting from.
(Its unlikely that they would make this stuff up, but you know more than me obviously however judging by the "hanging 40kg off the bumper" comment you don't know a great deal about aero )

 

[p4cks]

huh?

 

[jayxx83]

lol at hanging 40kg off the rear bumper!!! Go back to bed.

The underside of the 197 is pretty flat and the diffuser gives the air a smooth exit essentially creating a low pressure area underneath the car.

This essentially sucks the car towards the ground. With regards to the 200, if you look closely you will see the pipes are enclosed within the diffuser so as not to disturb the air exiting from underneath.

 

[Gaz_]

Oh hum.......


Its no flatter than a 172. And no i'm no areo expert, the comment was made in jest, but obviously lost in translation..........

Anyway, Cup racers still need a spoiler to clean up the air exiting the roof to diffuser.

 

[p4cks]

FWD cars do not need a rear spoiler, as they are useless. Ask yourself why a FWD car would need the rear wheels forced into the ground, when actually its the front ones that need the downforce.

The BTCC cars all have spoilers, but this is for aesthetics. They have even admitted this.

 

[Poopensharten]

Im confused...

Isnt the 197 rear wheel drive?

 

[realnumber 1]

FWD cars do not need a rear spoiler, as they are useless. Ask yourself why a FWD car would need the rear wheels forced into the ground, when actually its the front ones that need the downforce.

The BTCC cars all have spoilers, but this is for aesthetics. They have even admitted this.

A lot of front wheel cars have the rear spoilers to give the air a smoother flow off the back which can help with stability rather than give it down force. It can also help improve economy due to having less drag.
Iirc they had to add spoilers to the back window surrounds on the mk1 Sierra hatches because of stability issues at high speed.

 

[Duck]

FWD cars do not need a rear spoiler, as they are useless. Ask yourself why a FWD car would need the rear wheels forced into the ground, when actually its the front ones that need the downforce.

The BTCC cars all have spoilers, but this is for aesthetics. They have even admitted this.

FLOL. Spoilers on FWD cars also help keep the rear end planted, hence why many stripped time attack cars have huge ones.

 

[p@blo]

Quality thread. Simply quality. :clown:

 

[DNP182]

Quality thread. Simply quality. :clown:

'no spoilers' to this thread please

 

[ForceIndia]

FFS. Some very gullible people on here. It's for show.
IIRC the brochure for the 182 spoke about cup spec tyres, unique to the cup spec'd car.

 

[franx]

little fast cars , heavy engine in the front. Needs downforce on a light rear end, simple.

Renault learn a lot from their F1 technology (aerodynamics galore) ; along the years more + more of this knowledge is used in the production cars. Also at lower cost because so much knowledge has been built up already ; less research needs doing


These 197 and 200 Clios, why do you think they have such a good rep of "sticking" to the road ? A lot to do with the things talked about in this thread

 

[ForceIndia]

little fast cars , heavy engine in the front. Needs downforce on a light rear end, simple.

Renault learn a lot from their F1 technology (aerodynamics galore) ; along the years more + more of this knowledge is used in the production cars. Also at lower cost because so much knowledge has been built up already ; less research needs doing


These 197 and 200 Clios, why do you think they have such a good rep of "sticking" to the road ? A lot to do with the things talked about in this thread

Sorry, I don't believe it at all. Marketing jive, pure and simple. Pretty sure a 182 has bugger all rear downforce, yet can bang in pretty much identical lap times.

 

[DNP182]

surely it must do something beside just for asthetics????? otherwise you would just be carrying extra weight.

 

[ForceIndia]

surely it must do something beside just for asthetics????? otherwise you would just be carrying extra weight.

It looks nice. It probably weighs bugger all, but it's a great bit of styling. It's not a race car, not every part on the car is functional.

 

[DNP182]

lol..."it looks nice" lmao

 

[theduck]

I'm no aero expert, but I would have thought a 197 would be more likely to require downforce at the back because of it being longer?? Thats how its adding up in my head anyway.

Someone do a lap with the diffuser on and one with it off? lol

 

[ForceIndia]

And lol at 'downforce'. Diffusers reduce drag and lift, they don't produce downforce.

 

[DNP182]

so warren...what your saying is that the diffuser might just serve a purpose beyond 'looking nice' lol. this is a funny thread.