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Discussion Starter · #1 ·
Fitted these a few weeks ago to try to reduce road spray dirt. Successful at front and partly at rear. Front easy to fit, but wheels had to be removed to fit rears even with a mini driver.

The spray problem hasn't been reduced at the tail. Obviously, there is a vacuum set up to the rear which causes all the muck from the road to be thrown at the back window and tailgate.



Any ideas for alleviating this problem - would a spoiler help disrupt the airflow? If so, is there one for my 2011 Ceed 2 SW?
 

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It's the same problem the pro_ceed has. I've been modelling the car in Catia v5 so I could run some cfd. Personaly I think it's the underbody that causes most of the drag. The rear bumper is undercut and acts as a huge air brake under the car. That's what I believe is causing such an updraft and sucking road dirt up high onto the back of the car. Would also explain poor MPG some owners seam to be getting. Only been working it a week so watch this space. As silly as it sounds I think a diffuser or flat bottom would lessen the amount of drag and the amount of uplift of water/dirt onto the back of the car
 

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Discussion Starter · #3 ·
Good to know it seems to be a design problem. Perhaps a response from KIA design would be appropriate, especially if the company could come up with a retro solution. I'll put my thinking cap on too. Maybe a skirt suspended from the bumper shell would do the trick? Although this might exacerbate the problem further. You also may be correct re. MPG, but my results so far have been satisfactory: approx. 55-58MPG. rural.

Best wishes
 

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Isn't it just because the car has quite an abrupt upright rear end to it???

When I owned my Jeep Cherokee and my A-class these were both upright and square at the rear and the dirt over the tailgate and rear window was always much more extreme. Same with vans, squarer estate cars and coaches - the rear is always the first to get filthy.


Surely it just comes with the shape and style, not a design fault? A coupe, curvy hatchback or saloon wont suffer the same build up of road spray over the back windows as fast.







Edited by: micman
 

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This is an interesting discussion, I like the enthusiasm for solving the problem, though I agree it could be worse. I have noticed the same issue with my Cee'd. In my experience of other cars, mud flaps seem to be most effective cutting down the mud spray you get on the side of the car behind the wheels, less so with the rear of the car.

Good luck in finding a solution, I'm sure many of us would be interested to hear results of anything you try.
 

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Discussion Starter · #7 ·
Looks as if there is a bit of a hornet's nest being stirred here. Richie D76 comment was most constructive, and it will be interesting to hear whether his research turns up any solution. Thunderbird, on the other hand, seems content to state the obvious - yes, we have a rear wiper for the glass, but the real problem is the amount of dirt that gathers at the tailgate release, even after the shortest journey, and the fact that the instant one needs to lean into the Ceed's capacious boot lower clothing can be badly soiled.

Should we have to clean hands and trousers/skirts/coats everytime we want to access the boot?

Over 30 years I have owned six hatchbacks and estates. This is the worst for this problem, and must be caused by the aerodynamic design of the rear, and if as Ritchie76 states, the drag affects fuel consumption, it would be in the interests of the KIA image to come up with a solution to assist marketing.
 

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I think its the angle the rear screen lies at that causes suction of spray, as any car I have had that has a shallow angle e.g VX Cavalier, Capri, Primera the rear screen did not accumulate a lot of road muck but any cars I have had with steep angles has e.g Ceed, Rio, Leon, Clio.
 

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I dont think is a design "fault" i just think if on the pro_ceed at least, if youreach under the rear bumper there is a huge gap. On my old passat there was shielding that met the rear bumper from the bottom of the spare wheel well and arches to stop spray and dirt from being sucked up into the rear bumper causing drag/lift.If anyone can think back to threads about fauty reverse sensors due to water ingress, makes sence why it should be this way. Also explaines on the ESP thread how some owners have experianced a "loose" rear end at high speed. I can understand peoples argument that its just the abrupt rear end and its mostcertain the casue...although its not so much on the pro and i still get it bad! But the questions was any ideas how to stop the problem?
A spoiler will cause the air to seperate at the top of the car causing even more of a low pressure area at the top of the roof line to suck up spray. Next time I let the car get a bit of dirt on, i'll post a picture of how dirt is sucked into the space between the bottom of my wing and window glass.

This is no way related to just kia's. I'm 100% sure its related to every car maker. Although watch this space for exhausts on an up and coming sports car venting in a thin channel just infront of the rear wheel arches to act as an Air curtain, reducing drag.....Cant say anymore so ask no questions. But...wheel arches make around 40% of a cars drag, hence my most hybrid show cars have faired arches.

Edited by: RichieD76
 

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I've got over size flaps on mine - I still badly suffer with dust and spray both sides and rear.
I initially fitted mine due to stone chips along the lower sills.
 

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RichieD76 said:
I dont think is a design "fault" i just think if on the pro_ceed at least, if youreach under the rear bumper there is a huge gap.
Has yourback bumper been taken off andthe under bumper shield not been replaced? My SW has a plastic fairing under the rear bumper with a smallgap for the exhaust. Like all cars with an upright rear it gets dirty, saloon cars I have owned get dirty up to the rear edge of the boot. Mudflaps do not stop a car getting dirty, I live in a semi rural area which sometimes has muddy roads andthey do deflect mud and animal dung from the bodywork (not surprising) and help prevent stone and road grit damage. If I was an urban dweller I would not fit them.








Edited by: deeps
 

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Fitted these a few weeks ago to try to reduce road spray dirt. Successful at front and partly at rear. Front easy to fit, but wheels had to be removed to fit rears even with a mini driver.

The spray problem hasn't been reduced at the tail. Obviously, there is a vacuum set up to the rear which causes all the muck from the road to be thrown at the back window and tailgate.



Any ideas for alleviating this problem - would a spoiler help disrupt the airflow? If so, is there one for my 2011 Ceed 2 SW?
Please contact ChrisJBradyATyahooDOTcom re: British Seafarer and The Long March of Everyman
 
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