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-   -   Great success with airdam on '98 Odyssey (https://ecomodder.com/forum/showthread.php/great-success-airdam-98-odyssey-35498.html)

westygo 08-17-2017 01:36 AM

Great success with airdam on '98 Odyssey
 
I recently bought a great condition '98 Odyssey with 120,000 km on it. Great van, but wow, the underbody is absolutely horrible '
I bought a 6" strip of ABS, cut and drilled and bent and installed and have achieved a 16% improvement in fuel efficiency on the highway! This has paid for itself in a tank and a half of gas!
Pics to follow!

westygo 08-17-2017 01:42 AM

10 Attachment(s)
I simply used the factory attachment points, drilled holes at the bend points to eliminate the possibility of cracking and bolted in place. I bent the ends out to deflect flow around the front tires. Looks almost invisible, but does scrape parking curbs a bit.

Attachment 22412

http://ecomodder.com/forum/attachmen...3&d=1502948270

http://ecomodder.com/forum/attachmen...4&d=1502948297

http://ecomodder.com/forum/attachmen...5&d=1502948341

http://ecomodder.com/forum/attachmen...6&d=1502948363

http://ecomodder.com/forum/attachmen...7&d=1502948388

http://ecomodder.com/forum/attachmen...8&d=1502948407

http://ecomodder.com/forum/attachmen...9&d=1502948440

http://ecomodder.com/forum/attachmen...0&d=1502948462

http://ecomodder.com/forum/attachmen...1&d=1502948482

westygo 08-17-2017 01:44 AM

1 Attachment(s)
This is how ugly the underside is!


Attachment 22422

westygo 08-17-2017 01:50 AM

Next steps will be upper grille block, seal gaps and block off the edges of the lower grille that are not directly in front of the radiator. Also may add a belly pan up front that will shoot a bit past the dam and act as a splitter. This will allow spats in front of the front wheels.
So much potential on this great van!

freebeard 08-17-2017 03:54 AM

Nice work. Did you heat the ends to get them to hold the bend?

It will be interesting to see if the 16% holds up over time. Sometimes barometric pressure and other things can affect mileage in the short term.

Gasoline Fumes 08-17-2017 06:23 AM

1 Attachment(s)
Nice job, looks great! My parents have a '97, rebadged by Isuzu. I had a splitter on it for a while, but it eventually fell apart. I agree, the undersides of these vans are really bad!
http://ecomodder.com/forum/attachmen...1&d=1502965031

kach22i 08-17-2017 10:30 AM

Quote:

Originally Posted by freebeard (Post 547598)
Nice work.

Did you heat the ends to get them to hold the bend?

Those were my first two thoughts as well.

The material fatigue of bending without heat would be too much in the long term I suspect.

Super clean installation, professional looking.

I still favor my conveyor belt material, it has flexed when pulling off of parking curbs. Just a tiny bit on one corner caught a few times, but a harder material would have stressed out and maybe failed by now.

westygo 08-17-2017 12:10 PM

Thanks guys.
All bends are heat bent. The drill holes will go a long way to prevent cracking, and ABS is highly impact resistant, but not like conveyor belt.
Trying to follow the 80/20 rule and stick to big wins on this one, but it is tempting to go whole hog and belly pan the whole thing. Fortunately time is a big limiting factor. :-)

MetroMPG 08-17-2017 02:05 PM

Nice work, westygo!

How did you calculate the percent improvement?

Also: you must have one of the lowest post frequencies around here. (Join date June 2009! :D ) But you make up for the lack of volume with quality.

westygo 08-17-2017 03:52 PM

Thanks Metro MPG for the compliments.
Nope, I don't post much :-)
I keep tabs on every tank. Prior to installing the air dam, my best tank ever was 9.8 L/100km on a road trip. I repeated the road trip with the same cargo and same two bikes on the back same driving style same weather etc, and achieved 8.2 L/100km. Pretty sure that works out to a 16.4% difference.

MetroMPG 08-17-2017 04:00 PM

Thanks -- context is everything!

I think it's funny that the clearance you have with your new airdam is greater than the stock ground clearance on my Firefly. After airdam + lowering, I'm down to under 3 inches... and scraping often!

westygo 08-18-2017 12:34 AM

Yeah it sits pretty high... the first gen odyssey was built on an accord chassis. Seems logical that ride height could be returned to accord height.
I am surprised by the difference in economy. If 15% is that easy to attain, shame on the car manufacturers!

ecocruze 08-18-2017 04:21 AM

15% is phenomenal I'm looking at throwing something on my explorer for summer time would pull off for winter most likely due to Wisconsin snow. Figure if I can get 5-10% with that I may just be able to push 30 mpg. Keep posted with more tanks to let us know if improvement is holding or u just had a perfect foot for a tank.

kach22i 08-18-2017 08:17 AM

Quote:

Originally Posted by westygo (Post 547727)
If 15% is that easy to attain, shame on the car manufacturers!

I was checking out my cousin's new F-150 last weekend.

Ford did a bang up job on the front chin spoiler, don't think they left too much on the table on that project.

Of course the truck still looks like a brick. :D

MetroMPG 08-18-2017 11:53 AM

westygo: do you keep a public fuel log?

westygo 08-20-2017 12:20 AM

No, I don't keep a log at all, just check every fill-up. I've had this car for 4 months. Consistently 10.8 L/100 km mixed driving.
I do notice that the speedo reads high according to those radar signs that tell you your speed. It reads 4km/hr high at 45 and 6 or 7 km/hr high at 80.
So I am likely not going as far as my odometer says I am. Another manufacturer trick to make us think we are getting better mileage than we actually are?

Daschicken 08-24-2017 06:21 PM

Quote:

Originally Posted by westygo (Post 547727)
Yeah it sits pretty high... the first gen odyssey was built on an accord chassis. Seems logical that ride height could be returned to accord height.
I am surprised by the difference in economy. If 15% is that easy to attain, shame on the car manufacturers!

Yeah, that's a pretty huge gain to get from just an airdam. Carmakers in their infinite wisdom decided that interior space is worth big sacrifices in other areas. Case in point: That big honking spare tire well underneath the middle of the car!

7.5" of ground clearance is still a good amount considering that is after the air dam. I believe I have about 4" thanks to the wheel deflectors in front of the tires, my car scrapes more than the bro's lowered miata!

You guys are making me want to build a splitter for my car. :thumbup: It would help complete the look, since i've got that partial box cavity, or "drag wing" as some car people have called it sticking out the back of my car. :rolleyes:

westygo 09-25-2017 11:25 PM

Grille and fog lamp socket blocks
 
1 Attachment(s)
Still need to clean them up. Will install with black silicone.


Attachment 22760

MetroMPG 09-26-2017 11:08 AM

You're not going to make the upper block more easily removable? (Silicone.)

westygo 09-26-2017 01:18 PM

I figured silicone was a good removable solution. What do you suggest?

Daschicken 09-26-2017 02:04 PM

Quote:

Originally Posted by westygo (Post 551061)
I figured silicone was a good removable solution. What do you suggest?

Velcro would be more removeable, that's what I have holding my grille block on, that and a single screw.(which has saved the block from falling off... :eek:)

MetroMPG 09-26-2017 02:05 PM

Velcro is an idea, but I often find it's a battle between various adhesive strengths vs. the velcro itself.

I like stainless screws personally. You can put some backing material behind the grille and drill through that rather than through the grille itself (if preserving it is a priority).

freebeard 09-26-2017 02:58 PM

Tab and slot so the fastener only restrains movement and not separation.

westygo 09-27-2017 02:14 AM

Thanks for the input. I will reconsider!

westygo 10-09-2017 09:37 PM

4 Attachment(s)
Some more aero work today. Installed fog light pocket covers. Also did some more work on the front belly pan/splitter.

Attachment 22835

Attachment 22836

Attachment 22837

Attachment 22838

westygo 10-09-2017 09:44 PM

3 Attachment(s)
The belly pan is mostly so I have somewhere to install deflectors for the front wheels. While pondering how to attach it I realized I could just extend the pan past the dam and make a splitter. This should lower the stagnation point, reduce lift and send more air over the top of the car....I think.


Attachment 22839

Attachment 22840

Attachment 22841

Gasoline Fumes 10-09-2017 09:59 PM

Looks great!

freebeard 10-09-2017 10:30 PM

A narrow splitter will stiffen the edge. Decide if you want that. Flexible or brittle?

Wider ones will produce downforce. Decide if you want that. Handling or economy?

Some airdams have a notch in the center to cause a jet of air down the center while shrouding the wheels. Gasoline Fumes has an extreme example.

edit: what I'm talking about:

http://ecomodder.com/forum/showthrea...tml#post551905

Hey, it's in your thread.

westygo 10-10-2017 03:50 PM

I am thinking that because the clearance is so high (7") I won't need to let more air through. This is 100% for FE, my thoughts on thebsplitter are that lowering the stagnation point will cause more air to flow over the car, and therefore less drag. Is this reasonable?

freebeard 10-11-2017 04:33 AM

Not unreasonable?

The volume of air may matter less than the proportion that flows freely vs being blocked by the wheels. The idea of the central jet seems to be that it delivers energized air to the diffuser at the rear.

Air that is parted to the sides self-cancels (on average). Air that goes over the top contributes to lift.

Here's an example from history — a feature that didn't make it from Buckminster Fuller's Omni-directional Trasport, to its ground-taxiing test form, the Dymaxion
car:

http://ecomodder.com/forum/member-fr...f5307910-o.jpg

He called it an 'air keel'. It was a central jet on a tricycle that fed air to the empennage.

aerohead 10-14-2017 12:38 PM

splitter
 
There's a risk for the splitter producing un-wanted downforce (induced drag).
The only way to quantify it would be in a tunnel.
Just the 1.5-inch pipe insulation taped to the front of 'baby',to soften the lower leading edge created 103-lbs of downforce,@ 200-mph.
Hucho reports that lift isn't an issue for vehicles traveling at 'normal' highway speed.

westygo 12-03-2017 07:15 PM

2 Attachment(s)
Top portion of grille block installed! I used black zip ties, almost invisible and very secure.
Going to get myself some kind of instrumentation for Xmas so will be able to see actual temperatures hopefully.
In other news, as warned here in the forum, mythe bends on my airdam have started to break, so had to remove it. Plan b coming up!
Next mod will be a warm air intake. Looks like the easiest way will be to attach a "collector " to the manifold heat shield and run an insulated pipe or tube over to the intake which is just behind the passenger headlight.
Stay tuned!
Attachment 23107Attachment 23108

westygo 12-03-2017 07:19 PM

Aerohead, thanks for that info. I will start with the splitter lip plumb with the furthest forward edge of the bumper and see what happens. Can always shorten it if necessary, but as you say, no real way to quantify without a wind tunnel. Auto speed had a good article on how to measure lift, if I get that far. This van will likely never see any speed over 110 km/hr anyway.

freebeard 12-03-2017 08:18 PM

Where did the 'breaks' in the airdam start and which way did they propagate?

westygo 12-03-2017 08:33 PM

I had drilled holes at the corners of the tabs to relieve the stress before bending them over. I had been hitting a lot of curbs with the dam, and finally one of the end tabs broke off. Then another etc. The tabs broke right on the bend. So now I am looking for an extruded softer plastic "angle iron" to cut into new brackets instead of the one piece design I had. I will eventually be adding the front belly pan which will take the majority of abuse in the future.

BamZipPow 12-03-2017 09:30 PM

Quote:

Originally Posted by westygo (Post 555608)
Next mod will be a warm air intake. Looks like the easiest way will be to attach a "collector " to the manifold heat shield and run an insulated pipe or tube over to the intake which is just behind the passenger headlight.
Stay tuned!
Attachment 23107Attachment 23108

Any thought of using a separate heater core stuffed into the air box with its own control valve and plumbing the hoses off of the vehicle's heater system? You would be able to control the heat going to the air intake fairly easily. ;)

westygo 12-03-2017 09:58 PM

Yep, considered that option. The air box has very limited access and the heater hoses are tucked away deep behind the engine, so plumbing would be a big ordeal. Going to go the easier way. Might get a friend to program an arduino to drive a servo actuated flap to regulate intake air temp at some point. But baby steps first!

westygo 12-09-2017 08:01 PM

2 Attachment(s)
Upper grille block complete!
Attachment 23148
Attachment 23147
Almost invisible :-)
Hopefully I will get some time over the next couple days to start on warm air intake, or maybe get the air dam and front pan on.


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