ill be interested depending on how much you ask for the lot .
ill take one.

I'd be interested but would like to see a full review of one fitted to a coop and tested. If it provided only a few kgs of extra downforce, them I'm sure it would be noticed on a track or even fast motorway b road driving. An idea of price would also help me make up my mind

Ask any aerodynamic you trust and he will tell you it works!

How many kg's one can only guess without a windtunnel test.

Here's a pic showing the flow direction, how dirt/water has run along the top/diffusor ceiling, on one of the 2 middle plates:
http://sfk.ibk.se/forum/attachment.php?s=12d503ef044dde83ba5f51cedc5faff3&postid=82608

Actually, the fluid principals around this area are not that complicated as long as the rest of the floor is relatively flat. And the Coupe floor is VERY flat compared to most cars.

Feel free to compare with most std. "diffusors" on today's cars which has become a trend.. Almost every is near useless. The 500 Abarth diffusor actually looks like one of the most valid ones!

(another very "basic" area which works similar on many cars is the bootlid tail. That's why many upper-range cars have similar spoilers, such as the BMW M-cars, the Audi RS4, The AMG's etc. etc. The Coupe shape is not that different, so a "M3/M5-spoiler" is probably useful too. For better release/lower drag.)

per, on what basis do u claim the clio sport rear diffusor to be useless? i read that renault claims it produces significant downforce [40kg iirc?]. ive personally seen the diffusor and it's a better designed/made unit than the one on the coop. its larger, extends further into the car, and has the requisite 7-14deg rake.

the coop one is raked correctly but isnt near as large as the one on the clio.

redd

Ok that's a bad example from memory then, point is there are a lot of fake ones out there, just for looks.

The Renault: http://car4sport.ru/img/Renault%20Clio%20Sport%20V6_1.jpg

Yes it looks quite good, although it looks steep that angle. I hope there is no sharp break at the beginning, then it might work well.

Then again, who's going to make the effort to test the claims from Renault..? I think they calculated that too if you know what I mean.

There is no diffusor on the Coupe as std. Flat floor yes.

per, there is a diffusor on the coop. what ur referring to as a "flat floor" on the rear is a diffusor. it just doesnt have the pronounced "strakes" [the stock one has small ones] and "end plates" which uv added on to your diffusor.

redd

This is really getting OT..
But Redd, there is a certain aerodynamic function (incl. "suction" due to growing area) to a diffusor, see this quick funny scetch a mate did the other day:
http://sfk.ibk.se/forum/attachment.php?s=29937eaae5edc6199e4a0db4a8328c10&postid=54833

Anyway there is none of that on the std Coupe, just a flat floor and also an bumper edge spoiling the flow at the end.

I suppose what you could say is there's "half-a-diffusor" already. The "ceiling" of it.

Per, would you say you noticed any different to your car's high speed stability after fitting your diffusor? I'm sure that if it was going to work, it would be doing so and (quite noticeably) at 80-100mph...

No.
But the difference would be the same as having a big bag at the back.. And on Autobahn I've always had the car full of load anyway.. So - hard to tell!
A few kg's extra anyway, for sure.

tomorrow im going to pick up the coop wich went in for a radiator change, and i asked them to fit my apex springs ,
i just cant wait to see how it feels with the new springs.

cheers guys!

this is just incredible!! what a differnece 15 old car!! some say fiat are crap, some say tey are ok , but i think its excelent didnt expect so much grip with lowered spring , new rims, tyres, and suspension.
just loove my coooooooop!!!!