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Discussion Starter #1 (Edited)
It started out innocent enough...

When I bought the Insight this past spring, two items came to the top of the list.

1) Make oil changes easier
2) Replace the missing smoothing panel under the drivers side of the car

The first time I changed oil, it was 20°F outside in Wisconsin, and snow was falling in the driveway. I lay on my back with the car jacked up, *attempting* to get the panels off, to change the oil. Cold fingers on hard metal fasteners was not my idea of a good time.

Getting the panels back on took even longer, as the panels were 'tweaked' and jimmied back on by the previous owner. Needless to say, when warmer weather arrived, 'something' would be done to improve the situation.

Well, warmer weather did arrive in the form of 'summer' and I spent most of it, again on my back under car. But this time, with more purposeful disposition, that included fixing points 1 and 2.

Two air smoothing panels are now complete and on the car for the first weeks evaluation. You can see them here:

Picasa Web Albums - jsmosher - Air-Smoothing...

The panel under the engine vastly changes how the radiator block works. This spring I was running a 70% radiator block and could easily leave it at 50% blocked when the outside air temperature was 80°F or so.

Now I have completely removed the block after running the car on the Interstate highway as a safety check. With a 50% radiator block I saw temps as high as 204°F using a ScanGauge, just below the fan turn-on point. I typically do not run the car on the Interstate, but was curious what would happen.

The hot air intake mod is disabled for the time being. It was purposely only partially coupled to the intake snorkel to keep temperatures below 130°F, but now the under hood temperatures are so insulated that the hot air mod was generating temps above that temperature. Disabling it completely seemed easier than fine tuning it with outside temperatures close to 80°F right now.

With the radiator unblocked and running at 45mph on the back roads to work, I typically see radiator temps around 197°F or so, which makes me more comfortable, as I don't have to keep such a close eye on the ScanGauge while driving.

No Cd numbers yet, but that will eventually be done, when I finish smoothing out the rear of the car.

P.S. Highwater was an early inspiration to me. He posted some pictures of his 'engine blanket', and after numerous search attempts, I have been unable to find those early pictures he posted. Anyway thanks for getting things started.

Jim.
 

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Discussion Starter #3 (Edited)
Kevin,

Thanks Kevin, that's exactly what I spent many moons looking for!!

When I started the wheel well supports for the under-body panels, I looked in vain for those pictures, to remind myself how he did it. Very nice!!

I could have sworn however, that HighWater was the first to post about that design. Any relation to you?

Jim.
 

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Why did he block the holes where the steering arms pass through.

Does the shaped front wing (fender?) to promote air flow out of the arch region not give a clue as to what they are for?
 

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Discussion Starter #6
Hi johnnyvtec,

Why did he block the holes where the steering arms pass through.

Does the shaped front wing (fender?) to promote air flow out of the arch region not give a clue as to what they are for?
The blocked holes are there for several reasons:

1) When it rains out, and water is flooding the wheel wells, I am attempting to keep excess water from running on the *inside* of the panel by access through this area. Packed snow is another issue when it gets colder outside. I would have liked to close this area completely if possible, but some compromise had to be made to allow the suspension link and anti-sway bar to extend out.

2) The structure adds mechanical strength to support the panel in this area. Packed snow in this spot could easily break the panel if not supported here.

3) The area where the steering link passes through is *not* blocked, in hopes that flow through the radiator will pass through the engine bay and out this opening, to keep it from passing underneath the car. There is less drag by this method, and already allot of turbulence in this area.

The wing shape was added to maintain good air flow when the suspension is fully extended. I was trying to avoid a large hole in the flow coverage in this area. And the suspension hung down below the major flow path in this area. Thus the inverter wing shape to help maintain good flow and cover the dangling suspension link.

Hope this helps, Jim.
 

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Discussion Starter #7
The under-hood temperatures are more reasonable now. After finally getting in touch with a catalytic converter salesman through an acquaintance, I was assured that the converter could be insulated with fiberglass batting.

My concern was that the converter might overheat if this was done. The salesman mentioned that insulating it would actually improve how quickly it warms up and reduce pollution slightly, since it would be above the minimum operating temperature more quickly.

The goal of insulating the converter was to reduce the under-hood air temperature by shielding the main heat source. After adding the engine compartment smoothing panel, I did notice a more rapid heat build-up with the original 70% radiator block, with the fan close to the activation point (205°F).

Now the radiator block is back to 50% with the air temperature close to 60°F, and the radiator temperature is still at 197°F or so.

Jim.
 

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Been keeping an eye on your picasa album, great work. I would love to have time/place to make a set for my insight.


noticed any improvements for mpg or handling at highway speeds?
 

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This is fantastic work. I continue to be very impressed. Perhaps I have found my project for next summer if I can find the time and work space.
 

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Discussion Starter #11 (Edited)
Of the four panels that have been completed to date, these two were a lot of work. Especially the larger one, that covers the gas tank.

Not shown is a failed attempt one the first example of this. So the panel shown in this picture is the second attempt at doing this.

The panel is only 1/4 inch thick were it runs under the tank, and you can barely make out thin wood slats in the center of the panel. Making the panel this thin also means it is weaker mechanically, so there are two layers of 6 ounce glass on both sides of the wood to strengthen it in this area.



The muffler pipe runs way cooler than I first thought, and I *may* close over this opening next spring. The tail pipe will be wrapped with fiber glass batting to act as an insulator of heat.

I will probably also close over the brake cable openings, as the spring force of the cable is not that much, and it only extends below the panel at full suspension extension.

Jim.
 

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Discussion Starter #13
Hi,

The panels have given about 5 more mpg at 70% completion.

There are no plans to make large quantities of these, as it took three months to cover about 3/4 of the underside.

I'm still amazed that as the weather is really cold this week, one would think that the full engine panel would get the engine up to temperature quicker, and it does help, but not to the extent that I thought it would when working on it this summer.

We have had several nights close to -5°F, and even with a 3/4 radiator block, the car was still running on the cool side. Max temp with the ScanGauge was 197°F when running at 45 mph, and took about 15 miles to get there!

Jim
 

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Hi,

The panels have given about 5 more mpg at 70% completion.

There are no plans to make large quantities of these, as it took three months to cover about 3/4 of the underside.

I'm still amazed that as the weather is really cold this week, one would think that the full engine panel would get the engine up to temperature quicker, and it does help, but not to the extent that I thought it would when working on it this summer.

We have had several nights close to -5°F, and even with a 3/4 radiator block, the car was still running on the cool side. Max temp with the ScanGauge was 197°F when running at 45 mph, and took about 15 miles to get there!

Jim
It's time for a 98% grille block. I also find, at 60mph, that it warms up noticeably faster when the temperature selector is set to "cold". When it's -5°F, you're dressed in layers anyway, right?
 

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Amazing dedication and impressive appearance with good results (+5MPG) :) :D :)

But I hope the screws in photo #36 are installed such that damage to the plastic fuel tank is an impossibility. (don't forget long term chaffing either).

Also remember (especially in your location, salt exposure) that the steel fuel / brake lines may corrode more rapidly with "trapped" brine solution. An annual undercar inspection with a critical eye on these components would be a must.
 

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Discussion Starter #16 (Edited)
Also remember (especially in your location, salt exposure) that the steel fuel / brake lines may corrode more rapidly with "trapped" brine solution. An annual undercar inspection with a critical eye on these components would be a must.
Hi Trekker,

Actually, what you mention above is exactly what is in plan for this spring.

The screws by the gas tank do not touch the plastic material, so no scraping/chaffing in that area. They are only attached to the metal strap that holds up the tank.

There have already been some 'scrapes' from ice and slush in the road, and what better way to find out what needs improvement or reinforcing than a good ole' inspection when the weather starts to warm.

Also, after the inspection/repair session, coast down testing is planned to get some drag numbers.

Jim.
 

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Discussion Starter #18
I'm curious, What were the results of your coast down test?
I tried coast down testing, but found the GPS device not accurate enough to give good results.

Gas mileage data at the time showed a 5 mpg benefit.

I just logged 128 mpg for the third time this summer over a 33 mile course, coming home from work.

This is using slow driving, MIMA, FAS (just installed), and hot 90F temperatures.

Jim.
 

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5 mpg is pretty good.

I was thinking of putting some chloroplast over the pocket forward/left corner of the rear bumper (opposite side of the muffler).

Reason being a friend of mine has a hybrid civic, which he put a mugen body kit. He ordered the front lip first which got him 4-5 mpg more. But by the time he put the rear skirt on it dropped back down. We think it's acting like a parachute.

Anyways, I looked at my insight and there is a pocket back there. I can rig a small piece of chloroplast there, and maybe in a few more pockets. Place them strategically to get the most bang for my time (chloroplast is free).

I don't know how to do a proper coast down, but I'll get some pre-installation numbers, and do the same thing after they are installed. I’ll use the same straight road and initial speed.

Thanks for the info.

BTW - Maybe my car is missing a panel there (fwd/left of the bumper). Is it supposed to have one?
 

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Jerry,

Are you really able to drive highways speeds on Oʻahu for long enough distances for very slight aerodynamic improvements to be measurable? My experience on Oʻahu was that distances were so short and traffic so bad for so much of the time that extended highway-speed drives were difficult to maintain. Maybe you drive in the middle of the night :)
 
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