Air dam and grill block - Fuel Economy, Hypermiling, EcoModding News and Forum

Gasoline Fumes · 05-02-2010, 03:37 AM

I made an air dam and a grill block. The air dam is simply another bumper cover cut down and flipped over. Does it look effective? And the grill block is cut out of a Metro interior piece. Neither have been tested.

wyatt · 05-02-2010, 03:52 AM

It looks pretty good, the bits hanging down in front of the tires are where the gains will more than likely come from. Hopefully you made the grill block easy to work on, since you could wind up needing to at some point. With mine, I remove part of it during the summer and put it back in for winter. I would either remove the wiry parts in the center or attach some more of your grill block material to it to help lower the dam some more. I can't say whether the wiry parts help or hurt, but they just look like bits hanging in the wind. Are you going to do any testing on them? Let us know how they work out.

lunarhighway · 05-02-2010, 06:23 AM

that looks very effective and at the same time pretty cool and stock like. i'd say what's left over of the grill is likely not needed, but on the other hand it does lools nice, and it'll allow you to experiment with a small aditional block to see if it's better open or closed.

thumbs up

jime57 · 05-02-2010, 07:40 AM

I agree with the others. You should cover the left over grill pieces, perhaps in back with a piece of black coroplast. That would retain the look, which is very nice.

While on coroplast, I'd be very tempted to add a flat coroplast sheet across the bottom of the spoiler reaching back to the oil pan. That would smooth things out considerably on the underside. Leave a bit, an inch or so, of the flat sheet to protrude in front of the botton spoiler edge. I'm seeing this little splitter more and more on race cars. I think it might help keep a bit of air from getting under the car.

Very nice discovery. You have a good eye!

Gasoline Fumes · 05-03-2010, 02:32 PM

The grill block is only held in by four screws. And they're not even though it, just clamping it down. So I could probably rip it off without tools if I really needed to. But the slot between the hood and bumper is still open and there are two little openings in the slot on the bumper cover. I'm hoping that will be enough airflow. It has been so far, but Honda didn't give this car a real temp gauge, more like a 3-position idiot light. I should probably install an idiot light for the radiator fan.

I haven't decided what to do with the center of the dam yet. I thought about covering the bottom of the dam with coroplast or similar, but I'm not sure how long it would last. I scraped it once already.

What's the best testing method? I did actually try testing the grill block by coasting down a hill from a standstill, but the results were inconclusive. I was only hitting a peak of 48 MPH, I don't think it was fast enough to see a difference. I don't have anything fancier than a stopwatch for testing. How accurate is timing a high-speed coastdown? Maybe 70-50 MPH?

COcyclist · 05-03-2010, 04:21 PM

On the coast down testing, the higher speed 70-50 mph runs should be accurate enough to tell if it's helping or hurting. If you have a GPS and a passenger with a stopwatch, you can eliminate some of the human error. Try to do it on a calm day, in both directions on the same stretch of road and A-B-A runs if possible.

As for the scraping, in my experience the corners of the airdam scrape the most. Hopefully the bumper skin is flexible enough to bounce back. I agree that you may want to try a partial belly pan in the future. Very clever flip/flop air dam.

AeroModder · 05-03-2010, 04:24 PM

For coast testing, I'd measure distance rather than speed.

Gasoline Fumes · 05-15-2010, 03:32 AM

Grill block is out for now. I'll have to modify it or make another one for warm weather. I installed a light connected to the radiator fan and it was cycling on and off while driving. The useless temp gauge didn't tell me anything.

wyatt · 05-15-2010, 10:48 AM

Quote:

Originally Posted by Gasoline Fumes

Grill block is out for now. I'll have to modify it or make another one for warm weather. I installed a light connected to the radiator fan and it was cycling on and off while driving. The useless temp gauge didn't tell me anything.

How did you install your fan light? Is it just an LED and some wiring, or did you put a resistor in line? A wiring diagram would be helpful for those of us not too electrically inclined. Thanks.

robchalmers · 05-15-2010, 10:56 AM

I'd mount your auxiliary lights in the bumper and add a flat bottom and wheel deflectors to the underside. A part from that it looks very cool, i love the idea of flipping a seconder bumper!