Rear Wheel Skirt using water heater drain pan

[cfg83]

alohaspirit -

Originally Posted by alohaspirit

I think this is a great mod cfg83

hope to see updates

(maybe I should splurge and get 2 pans)

Thanks, I literally took maybe a year of looking around for what was in my head. I mostly looked in plant nurseries at the plastic "dura cotta" saucers, but they only got as big as maybe 20" diameter. Then one day I gave the plumbing section a try in Home Depot, and there they were, looking at me, as if to say, "where have you been all this time"?

I also think that they can be a stepping stone for a bolder aero mod :

rear wheel skirts...

Originally Posted by cfg83

malibuguy -

...

I have been thinking that my mod is probably better as "infrastructure". If you look at the picture above, you could cut out the center and use the surrounding "frame" as a base to attach varying skirt designs :


(the dots would be fastener locations)

The cool part is that the skirts could be attached with "quick release" connectors like dzus fasteners. You would have full access to the tire and you could more easily try different wheel skirt designs.

https://www.pegasusautoracing.com/pr....asp?RecID=758


...

I think that doing this would also negate the problem I cited in post #13 above, because cutting out the middle of the drain pan would make it more flexible to fitting in "close-but-no-cigar" wheel-wells.

Cutting out the middle is based on jthistle's idea of using a wheel flare as a "base" for a wheel skirt :

http://ecomodder.com/forum/showthrea...kirt-4504.html

However, I think the drain pan is a better "base" for mounting wheel skirts because you don't have to deal with the "curve" of the fender flare (hard to describe). You just have to mount the cover on a uniform "flat" surface. If I was more bold, I would make a cover for mine that looks something like this outline :



CarloSW2

.

[cfg83]

Hello -

On my home to work route I got 61.8 MPG today. That is 0.2 MPG below my all-time record. What is interesting to me is that I had been driving without my rear wheel skirts for the last two weeks (removed for car wash and wheel rotation). :

1999 Saturn SW2 Trip Log : home to work ; 2009/03/25

ROUTE : 10 West -> 710 South -> 105 West -> 405 South -> Exit Freeway => Roughly 27+ miles
----
NET ELEVATION CHANGE : ~210 feet drop
----
SCANGAUGE "CURRENT" READINGS :
61.8 MPG,
0.4 Gallons,
206 Water Temp Max,
27.7 Miles,
2079 RPM Max,
0.5 Hours,
59 MPH Max,
47 MPH AVG
----
IAT READING : Hot Air Intake + dynamic grill block led to Input Air Temp readings of around 140+ degrees F.
----
WEATHER(.com) :
72.5 degrees F,
Sunny to Fair,
18.5% Humidity,
27 degrees F Dew Point,
30.045 in. Pressure,
----
TIME : ~11:16 AM to ~11:46 AM (PST), ~30 minutes
----
RECENT CAR CHANGES : I had just restored my rear wheel skirts. They were off for a week or two because I had my wheels rotated and a car wash. I went to an increased oil filter size on my last oil change. I also have a "dynamic grill block" mod that I haven't published yet.
----
HYPOTHESIS : "Good" Goldilox traffic (not too pushy). Bone dry weather. If I had a snail to follow, I think I would have hit my record.

I think that without the skirts, at my *minimum* assumption of a 1.36% gain, I would have lost 0.84 MPG, which would have knocked me just below 61 MPG.

There are a few other small mods I need to publish, but I think this is pretty neat.

CarloSW2

[alohaspirit]

nice update

I would love to get 61.8mpg

sheesh, Id love to even get half that (30.9)

[cfg83]

alohaspirit -

Originally Posted by alohaspirit

nice update

I would love to get 61.8mpg

sheesh, Id love to even get half that (30.9)

Thanks, this is my "milk run", where all my best MPG comes from. I drive about 7 miles on city streets before I reach the freeway, so the engine is nice and toasty warm. These recent mods *might* have also helped, but it's way too early to say :

http://ecomodder.com/forum/showthrea...lter-7601.html
http://ecomodder.com/forum/showthrea...lock-7603.html

CarloSW2

[tf4624]

Looks good I have stuff on my Prius LOL

[cfg83]

Hello -

Ok, I took my own advice and started a v2.0 wheel skirt. The problem was, the v1.0 skirts took maybe 15 minutes to take off but then it took at least an HOUR to put them on. This discouraged me because I would take them off before taking the car for service and then *leave* them off because it was too exhausting to reinstall them (mee lay-zee).

Now, I already had this idea of turning the outside of the skirt into a flush "trim piece" with holes :



I made a cover piece like this :



I used plastic pop-rivets, but I was fearful that they might hit the tire if I went over a pothole or something. Therefore I trimmed some of the rivets and used a plastic washer to reinforce them :



To demonstrate how little they stick in, I did this demo reverse-mount :



Once it is installed it looks like this :



The number of rivets is not symmetric. The forward leading edge has two extra rivets to keep the wind from sneaking in and trying to open up the skirt.

Now, there was a problem that I predicted but didn't see for maybe two weeks. One morning on the freeway I heard a loud *BAM* like a rock had bounced up under my car or something. Once I was at my destination I realized that one of the wheel cover bolts had hit the skirt. Here is a view of the inside of the skirt :



The good news is that :

1 - The skirt was barely damaged, it looks normal on the outside.
2 - The wheel cover did not fail. It does have a 2" crack near one of the bolts, but it's otherwise fine. So fine, in fact, that I have left it on.

This makes me happy because the system "failed gracefully". It has also motivated me to look for a more flush wheel cover bolt system. This is the direction I am going :



And here is another comparison showing the old sticky-outy bolts and the new flush bolts + the skirt :



In addition, my cohort and I will be working on a trim piece to keep the lower edge of the skirt from *ever* doing this again.

I will publish the new wheel cover bolt installation system in another thread, but me too tired.

Here is the current look :



CarloSW2

[sl2eggplant]

CFG, You ROCK!!

This may help those who do not have a wheel well with close/same size as the block water heater pan. I would recommend cutting the pan into 4 equal slices. Take two slices and spread them apart or bring them closer together to fit your wheel well. Overlay a clean sheet of coroplast or other material.

[cfg83]

sl2eggplant -

Originally Posted by sl2eggplant

CFG, You ROCK!!

This may help those who do not have a wheel well with close/same size as the block water heater pan. I would recommend cutting the pan into 4 equal slices. Take two slices and spread them apart or bring them closer together to fit your wheel well. Overlay a clean sheet of coroplast or other material.

Thanks! Yes, the "flush frame" idea can accomodate anything. If I was doing an economy run, I might extend the wheel skirt front and back. The defect in my design is the blunt frontal surface/transition. I have some "ideas" for dealing with that, but none that I like.

In another post I will show some of the construction process. My friend helped me cut the drain pans with his bandsaw. Without him, I wouldn't have been able to do it.

CarloSW2

[NachtRitter]

Carlos -

Really enjoyed this thread... I am adopting the idea for my VX.

Question for you... did you end up getting another water heater pan for the material you used for the 'cover piece'? Or did you use some other material altogether?

[cfg83]

NachtRitter -

Originally Posted by NachtRitter

Carlos -

Really enjoyed this thread... I am adopting the idea for my VX.

Question for you... did you end up getting another water heater pan for the material you used for the 'cover piece'? Or did you use some other material altogether?

Yes, I retired v1.0 and bought two new pans. There is a 1" overlap of the pans. There is a little "belly button" of plastic at the dead center of the drain pan where I think the plastic was injected. My friend made that the center point and we nailed it down onto a board. Then we ran each pan through his band saw by turning it around that center point. That was the key to cutting it accurately. Otherwise it would have been agony to cut by hand.

I had pictures of the process, but I can't find them right now. Here is the picture of the overlapping pieces before I made the holes :

Apart :


Overlapping :


Also, I didn't have to retire v1.0. I could have just cut it and used it as the trim piece that you see. However, then the circular cut would have been more problematic (allthough still doable). Also, the covering doesn't have to be plastic, it could be metal. The trim piece is just the "base".

CarloSW2