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-   -   Single front wiper crx? (https://ecomodder.com/forum/showthread.php/single-front-wiper-crx-7115.html)

chipX 02-14-2009 03:17 PM

Single front wiper crx?
 
Do you think the gains of a single front wiper on a crx are worth much, if anything at all?
Obviously one wiper will be half the drag of both - but do they actually make much drag at all ?

(At higher speed my wipers start to get pushed up the screen - almost as far as half way lol . It seems a common problem, a few people from crx uk raise the bonnet, making the air flow over the wiper. Some other members move their wipers as far down as possible... so they are sitting on the black plastic trim.
The other members just buy new wiper arms lol ;) )

However it does say there must be some wind resistance acting on the blade/ arm - put it this way even pushing the wipers up with your arm is almost impossible.

But that would be a different topic ( infact i might make one about the bonnet raising mod )



So back to the single wiper :

Im not talking about removing one wiper and using the other , i mean a proper conversion that gives full sweep from one wiper....

Could run it to the side
similar to this crx

http://img404.imageshack.us/img404/6...2008066it5.jpg

Or even more sleek ( but blocking a little vision ) straight up :
Sorry for poor pic
http://home.online.no/~kseland/s_wiper.gif

winkosmosis 02-14-2009 03:33 PM

I think the best thing to do would be to make a lip that directs air up over the wipers. That way you aren't compromising safety or going through the trouble of modding them. Remember, any energy you save will be cancelled out if you get into an accident and have to send your CRX to the junkyard.

chipX 02-14-2009 03:41 PM

The first picture is a proper kit, and gives the full sweep of the screen...
Just like some of the mercedes and lamborghini's have single wipers

red91sit 02-14-2009 03:46 PM

Quote:

Originally Posted by chipX (Post 87794)
The first picture is a proper kit, and gives the full sweep of the screen...
Just like some of the mercedes and lamborghini's have single wipers

My benz used a very strange setup where it looked like one wiper, but it was really two that rested flat, and one wiper covered the whole winshield while the other traveled at half the speed to cover just the passenger side. Didn't seem to have any advantages over conventional wipers. But sure was cool

MetroMPG 02-14-2009 04:09 PM

re91sit: I remember seeing those! Weird.

chipX, my ranking, best to worst (considering aero, practicality & safety):

- sheilded wipers
- 1 exposed wiper parked vertically in the center
- 1 exposed wiper parked normally
- no wipers (safety)

lunarhighway 02-14-2009 04:15 PM

the opel eco speedster had a single vertical wiper and an 0.20 Cd...
not that there's a direct connection, but i'm sure they would have gone for something else if it added more drag than standard wipers

http://i77.photobucket.com/albums/j5...pt2002-001.jpg

aerohead 02-14-2009 04:38 PM

wiper
 
During development of their PNGV Car,GM noticed during windtunnel evaluations,that the windshield wiper had virtually no impact on drag.-------- I eliminated the wipers on my CRX at Bonneville and it had no effect on top speed.It's possible that the high-pressure bubble just ahead of the windshield "shields" the wipers from the outer flow.

Frank Lee 02-14-2009 05:16 PM

^Yes the evidence suggests to me the flow in that region is really quite stagnant on my car and probably the CRX- or any "3-box" design too. As the new stuff approaches a "1-box" design (having a very sloped hood and almost the same angle to the windshield) I suppose it probably would be a different situation via the lack of that stagnant "bubble".

And, not that I have links or anything to back it up, but I would think the vertically parked wiper would be the WORST. For one it's up out of the "bubble", for two vehicles out in the world are for all practical purposes always in yaw. So imagine crossflow across that windshield.

I can think of a reason northerners might like a vert wiper: probably would have a much less tendency to freeze into that big pile of snow and ice we always have at the base of the windshield.

"Do you think the gains of a single front wiper on a crx are worth much, if anything at all?" No.

hypermiler01 02-14-2009 07:02 PM

Frank, what's up with you and yaw, yaw, yaw? If you are traveling down the highway at 70, and you have say a 5mph crosswind at 45 degrees, the resulting yaw vector is so small as to be negligible.

If you have hurricane force winds at exactly 90 degrees to the road, yaw might be a concern, but most of the time around here, any breeze is so slow that you can barely feel it.

Just look at all the tuft testing pics posted on this forum. Generally the tufts are pointed straight back.

MetroMPG 02-14-2009 07:43 PM

Quote:

Originally Posted by Frank Lee (Post 87811)
And, not that I have links or anything to back it up, but I would think the vertically parked wiper would be the WORST. For one it's up out of the "bubble", for two vehicles out in the world are for all practical purposes always in yaw. So imagine crossflow across that windshield.

Thanks, Frank - I stand corrected! I fell into the same trap I occasionally remind others about: forgetting about yaw, or apparent flow direction when saying there's no need to remove the fore/aft roof rack rails/mounts because they present little projected area.

So I correct my list: the vertically parked, centrally located single wiper is best only when used with a wind direction indicator.

:p


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