Moon Caps - Any Value on 1st gen. Honda Insight? (A-B-A coastdown test)

[jime57]

Originally Posted by darcane

Add one more to the list:

G/GT record holder at Bonneville.

Interesting, but Moonies are a knee jerk at Bonneville. Where's the wind tunnel data

[Sven7]

So, if you already have the moon caps, test the buggers! Try something like 80-40mph and see if they show up. Remember, the higher the speed, the more difference aeromods will make and the easier it will be to see them in test data. Maybe try an ABABA?

[NeilBlanchard]

Smooth and flat is better than smooth and domed. The convex dome sticks out and has more drag than flat covers. As long as you're trying to improve things, go flat and smooth.

[MetroMPG]

I'm pretty sure Phil has posted before that a convex wheel cover/shape is better. I'll search around to see what I can find. Can you point to a source for flat being better?

EDIT: found the post - it's not conclusive.

Originally Posted by aerohead

I dug into my mess.I'd read an explicit argument somewhere about the merits of the convex vs flat covers,however did not,or could not copy the article,so I don't have it.
So all I can do is default to Shinella's R&D of the Trans Am at Lockheed,Marrietta.They got numbers for an open steel wheel,a vented flat wheel cover,the same cover taped closed,and Shinella's
secret weapon discs which shaved another 0.003 off the Cd.
The production covers are convex and also vented and no data are presented for them,nor are the secret covers shown.
Since Ultralite sports a shallow convex,minimally perforated cover,and at 100-mpg,being fully optimized for low Cd,I would be comfortable with the notion that the crown of the convex cover has a distinct advantage over the flat.
We're splitting hairs though I think.

[Beau]

Not that it would be an ideal wheel from a weight perspective, but for those running stock steel wheels that accept a stainless beauty ring -- would it not be a very simple mod to first fasten (screw/rivet) the Moon (or similar) disk to the beauty ring, and allow the spring tension of the beauty ring to hold the disk/ring to the wheel (it was designed to do so)? This would seem to minimize some of the downside/difficulty in using/mounting/servicing wheels with disks. No?

[jime57]

Originally Posted by Beau

Not that it would be an ideal wheel from a weight perspective, but for those running stock steel wheels that accept a stainless beauty ring -- would it not be a very simple mod to first fasten (screw/rivet) the Moon (or similar) disk to the beauty ring, and allow the spring tension of the beauty ring to hold the disk/ring to the wheel (it was designed to do so)? This would seem to minimize some of the downside/difficulty in using/mounting/servicing wheels with disks. No?

I think that would work, but why not just buy the clip on Moons. They have little steel fingers and mount like a regular hubcap. I knew one guy who had trouble keeping them on, but others experience is that they work fine.

[Beau]

Originally Posted by jime57

I think that would work, but why not just buy the clip on Moons. They have little steel fingers and mount like a regular hubcap. I knew one guy who had trouble keeping them on, but others experience is that they work fine.

Only because I have been told the failure rate with the clip-ons actually staying clipped on has not been good. No other reason.

[jime57]

In the case of the Insight, I'm a Honda believer. I deeply suspect that they did the best that they could in the wind tunnel. It is true that the current wheel has some minor styling touches, and some small spoke slits, but it works very well with the current fender design, which incidently is far different than your "normal" car. If I had to venture a guess, and we are all guessing at this point, I'd guess that a FLAT cover would make a small, very small, improvement. If I test I'll do that first The Moons stick out way too far.

[Sven7]

Originally Posted by Beau

Not that it would be an ideal wheel from a weight perspective, but for those running stock steel wheels that accept a stainless beauty ring -- would it not be a very simple mod to first fasten (screw/rivet) the Moon (or similar) disk to the beauty ring, and allow the spring tension of the beauty ring to hold the disk/ring to the wheel (it was designed to do so)? This would seem to minimize some of the downside/difficulty in using/mounting/servicing wheels with disks. No?

http://ecomodder.com/forum/showthrea...tml#post332964

[jime57]

OK, I'm warming to the idea of testing the Moons. I did a measurement with crushed aluminum foil behid the Moons and found that they are only .6" more into the airstream. I'm trying to find a way to mount them temporarily without drilling my wheels - for the time being.

I went out looking for a test course. Richmond is terrible with hills, but I think I found an essentially flat section I can use. I did a few experimental 70-50mph coastdown runs and I think the course will work ok. Perfectly flat would be better, but that just isn't available anywhere around here.

I do have one technical problem. How in blue blazes do I mark the end of the coastdown at 50 MPH? Remember, I'm going 50 so I can't just step out and put a chalk mark on the road