Wiper cover test
 

Searched a little on the site and didn't saw any wiper cover example. As it seams my groar's 2001 Scenic Modding Thread haven't been read a lot (at least it didn't received a lot of reply), I'm promoting my Wiper cover test message as a new thread in the hope others to be inspired, and do better benchmarks ;)

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During two weeks I also tested a wiper cover. As it was only a coroplast sheet taped with transparent tape, I had always an eye on it when I was driving with it. While driving it was always very stable, except when a truck was overtaking me then the left part was shacking a bit. I was also inspecting how well it was taped before driving.

I had a "no rain" position (1st and 2nd picture) and a "may rain" position (3rd picture). When driving the coroplast was pushed down and in the "may rain" position it was only at 0.5 cm over the wipers. The vertical sheet in the "may rain" position is simply stuck between the fixed and mobile parts of the hood. It can be put back and removed without untapping the cover.

Not only it removed the wiper from the air flow, but it also smoothed the angle between the hood and the windshield.

My best daily commute consumption since my first message in this thread is 57.3mpg. It has been done with the wiper cover in "no rain" position. The following best daily commute in that tank was 51.4mpg. But this record may have been helped by a very warm 18°C (64°F) day...

With cover 3/4 of daily commutes were over 47mpg while without cover 1/2 were under 47mpg before (with same temperature range and "full" grill block).

In my daily commute, when I leave the freeway I have to pass over it thanks to a bridge. At the top of the bridge I'm at 60km/h. I coast in neutral to go down. Without the wiper cover I reach 76-77km/h max at the bottom. With the wiper cover I reach 79-80km/h. I tried to follow the same curve, parallel to the right line. I did it 10 times with the cover and 5 without.

A funny thing : when it was raining then the drops fallen on the windshield under the level of the cover were pushed down to the wipers, effect helped by the fact I used an anti-rain product on the windshield.

I think this cover is a success :)

If I put the cover back then I will cut the lower corners so they are not pushed up by the upper sides of the hood. May be that will permit the hood to be opened without removing the cover. I may also cut the cover so it stop just before the wipers, which may help finding a "any rain condition" configuration.

Denis.

http://ecomodder.com/forum/attachmen...2&d=1227344162
http://ecomodder.com/forum/attachmen...3&d=1227344162
http://ecomodder.com/forum/attachmen...4&d=1227344162

That's a larger version of the wiper wind deflector installed on my car. With mine, I didn't notice any significant improvement in mileage although it did reduce the wind noise and the amount of ram pressure (no fan) air flow coming through the vents.
http://img.photobucket.com/albums/v4...Shieldside.jpg
http://img.photobucket.com/albums/v4...hieldfront.jpg

I found your results interesting. Thanks for posting.

Have you considered just removing the wipers ?

If there is a chance of rain, both wipers can be reinstalled in less than a minute - just push the wipers back into place and replace the bolt. I did this recently on a trip with no problems.
( Be cautious to have the wipers line up correctly with the teeth of the gear though )

I made one... couldn't tell any differences in mileage or anything. Off it went. I don't think there's really "flow" in that region, at least on my cars.

I'm not very comfortable with the idea to have no wiper (even if I know I can put them back in one minute), but I may try it if weather forecast is optimistic. For the next few days they are talking about snow and sub 0°C temperatures...

I don't have an idea if the improvement comes from the wipers removed from the air flow, or the angle between the hood and the windshield which is flatter, or both. The no wiper test may help to decide.

Denis.

A wiper dam is planned for my car since they are most definitely in the airflow, but I'll be shooting for a more subtle "basjoos" style. Spring cannot come soon enough... *grumblestupidcoldweathergrumble*

At least I've got my Guino so I'll be able to see any MPG increase instantly... you know, once its installed and stuff :D

Heres mine I did earlier this year. I couldnt tell one way or the other with mpg. But it certainly does not hurt.

http://ecomodder.com/forum/attachmen...1&d=1217991310

How do you know they are most definitely in the airflow?

Mine were very similar to wagonman's- mine went up the windshield a little further and had some more "fillet" to them. Anyway, I made it two piece, left and right. After going through the rain with no wipers and no noticeable fe results I re-installed the driver's wiper and left the passenger side fill panel. On my car I have noticed, fill panel or not, identical behavior of raindrops on the windshield. That is, on about the bottom 1/4 to 1/3 of the windshield, the drops just sit there even at highway speed, whereas on the rest of the windshield they are blown up and to the sides. That whole zone of drops sitting there stationary tells me that flow velocity there is not high at all. So the aerodynamics books I read were right: there is a fairly stagnant high-pressure "bubble" in that region, on cars like mine and wagonman's.

Now, that Renault has such a shallow transition there at the windshield base that I would not want to venture a guess as to whether it has the above described situation.

Frank - My Topaz always "wagged" the windshield wipers at high speeds (post-80mph).. I know you don't drive that fast, and that was the only time I ever saw it happen... but I figured it was interesting enough to post.

When I say "wag", I mean they would waver a little bit.. within the confines of freeplay, and not at a given frequency... I think it had alot more to do with oncoming traffic blasting jets of air, which disrupted my own airflow, but I can't be sure.

Reminds me of when I was airing the tires on the Tempo and forgot I set one of those standard black plastic valve stem caps on the cowl panel. 350 miles later when I got home I discovered it still sitting there! :eek:

Anyone still think there is "flow" there?

I know there isn't on my car. When my xB is dirty, and there's rain or dew on it in the morning (not so much now, since it's winter all of a sudden), one can very easily visualize the flow along my hood:

http://img227.imageshack.us/img227/1...4016rg1.th.jpg

http://img404.imageshack.us/img404/2...4017vf7.th.jpg

I think a lot of this is due to the odd shape of my car, but even more conventionally shaped vehicles can't possibly have the wipers sticking all that far out into the flow. Like basjoos pointed out, the main advantage is to reduce noise and ram pressure.

As you can see in the 3rd picture of the 1st message of this thread (forget about the coroplast sheets), the angle between the windshield and the hood of my scenic is nearly flat, so I think the wipers are in the air flow.

In the newer version of the scenic, the wipers are hidden behind the hood. I can't find a static link on renault.fr/.com with an adequate picture... I should get a picture of my parents in law's scenic next Xmas.

Denis.

On mine, raindrops hit the entire windshield regardless. But before the cover, driving to work in the morning would burn off all the morning dew. After the cover, the dew on the bottom third or so would still remain.

Below is my van, just a different color. The wipers are RIGHT in the airflow.
http://www.carsurvey.org/images/pont...ns_sport_1.jpg

That's a Chevy Lumina APV or copy of it... those were always decent vans, that I remember, and easy to get parts for, b/c of the relative number of Lumina models that were broken and no one wanted to fix them.

I can tell from the bugs impaled on the wiper arms that they sit in the airflow, also from the wiped water that tries to flow up the windshield between the wipers.

Here they are :

• Right : http://ecomodder.com/forum/attachmen...8&d=1234727387
• Front : http://ecomodder.com/forum/attachmen...9&d=1234727387

Denis.

The reason some of you guys have stationary air on the lower few inches of the windshield might be because of the wipers blocking flow :p

On my car the raindrops reacted to air currents on the windshield the same with or without wipers.

I bet the wipers on that van make a huge difference in aero. The more equal the angle of the windshield is with the hood, the less of a high pressure dead spot there will be, so the van would have none.

This is what we have done so far for the wiper cover.

Got my doubts also:)

Hey thanks for posting this, This is a really old thread, but i couldn't find anything like this on the internet, im going to do this with my 2015 ford Taurus.

The low effort route is to simply remove the passenger side wiper and carry it in the glove box.

I can not afford to take off a window wiper. Due to i live in canada and it is winter time, and this is my winter car.

I like to think there are nice things about Canada that balance it all out. :)

One of these?
http://images.newcars.com/images/car...n-Exterior.png
http://images.newcars.com/images/car...n-Exterior.png

The wipers are semi-recessed in a likely high pressure area (the air building up against the windshield). Small gains to be had. Those rear view mirrors are like elephant ears.

I know on my fusion, they hide down below the hood. On my ranger.. Heh..

They are definitally in the windflow. At highway speeds they ride about 1cm higher then they do when parked. Mind you my hood is flat and the entire assembly sticks out above it, there really isnt a cowl the windshield slips under.

This recent thread bump reminds me I never did make my "quick release" wiper arm.


I typically travel with the passenger arm removed, but will re-install it depending on the forecast. On some cars removal/re-installation is easier (Metro/Firefly) than others (cars with semi/recessed arms).

Jeeps have quick release arms stock. They come off with spring loaded clips.

Well, I'll be. Learned something new today...

https://ecomodder.com/forum/attachme...1&d=1576198980
From: https://www.cherokeeforum.com/f59/ho...per-arm-58818/


https://ecomodder.com/forum/attachme...1&d=1576198956
From: https://www.allpar.com/fix/wiper-linkage.html

I should dig up that old thread and update it.

they have quick release wipers in the stores :D pricey at 20ea though


don't expect too many off and on the car cycles though

F150 and the Tempos have that exact clip as the Jeep. I like that set-up and it would be nice if all my stuff had it. I run no or just the driver's wiper most of the time, not so much for aero but in the past when I didn't do that the wiper blades would age out with so little use on 'em. Now they last forever.