Honda Element Owners Club banner
1 - 5 of 5 Posts

·
Registered
Joined
·
108 Posts
Discussion Starter · #1 · (Edited)
This is another long explanatory post, but if you're interested in a slick-looking scoop or snorkel without permanently modding your hood or fender, stick it out and read on:


When I was producing the CAD models for the control panels of my new camper setup, I realized that I could have some extra fun with the fused deposition modeling machine. Basically, I could have any reasonably small parts that were producible in plastic, with my imagination as the limit.

I realized that this was all well and good for interior parts, but if I could only make things in plastic, that doesn't leave much that I could do for engine or performance parts. However, while changing my wiper blades, I noticed that the trim piece at the base of the windshield is shaped in such a fashion that it had a reasonably sized volume underneath it, and that it had a large vertical face on the inside of the engine compartment.

I went to work taking out this piece of trim and used a dremel to make a hole on the inside, where the plastic sits on top of the firewall. I then put a matching hole on the outside, where the trim piece has the gridded vents. I was careful to pick the one spot where I had measured that a significant amount of air volume could be forced into the space between the wiper motor and the base of the wiper itself.

Using a contour gauge, I got the necessary data points to make a 3D modeled scoop and airbox that would fit seamlessly to the upper and lower part of the trim piece. I designed the scoop so that it was only a few inches tall and protruded onto the hood surface just a few inches in front of the left side wiper. It's actually quite clean and inconspicuous looking. The scoop was finished flat black and fitted with a rubber seal to insure an aerodynamic pressure effect (ram air). It is attached via 4 holes in the trim piece with the snap-in/out body fasteners. The airbox that is used to direct flow from the scoop back into the engine compartment is simpler in shape and permanently attached with epoxy. A circular flange is mounted on the inside of the trim piece above the firewall where it can then be routed directly to the stock airbox that contains the filter. I had previously removed my resonator to make way for a bigger battery.

Anyway, the BAD NEWS:

I broke my damn ankle before I was able to buy the hose to route from the firewall to the filter housing. Therefore, I have no manifold pressure readings at speed from my scangauge yet. Performance-wise, at the very least this provides a slick-looking cold air intake. However, I'm not one to make theoretical before I test it out.

As I live in a 3-story apartment building, I've been sitting on my ass for the past few days until the swelling (which is causing most of the pain) goes down and I can crutch around in an upright position without my foot filling with excess fluid. When I'm feeling better, I'll take and post pics as well as engine statistics.


What I'd like to know:

Since I have the 3D models already built, and I have enough FDM material to make one or two more prototype versions, I plan on testing and improving the design and possibly making it available to other Element owners as a kit. Pricing would be fairly cheap, as you have to cut your own trim (I'd provide templates) and I think all E fans should get this basically at cost+shipping.

The reason I'm trying to get an idea of how many people are interested is because the cost will undoubtedly be dependent on how many of the plastic pieces I have made. I don't know any low-run plastic manufacturers, but I'm looking in to it this afternoon. Please post ideas/interest in this thread, as I would not be looking forward to a ton of PM's to get back at.

Oh, and those of you who have interest in this being used as a snorkel, some further design development would be necessary to ensure that water does not enter the engine. Currently, as a ram air setup, any rain or splash water that goes down the tube would be taken care of in the filter box, as honda has included little release/drain holes that allow water to leak out without much of a pressure change.

Addendum: As per the EOC forum rules, I can't just be soliciting new products all willy-nilly here. I'm basically trying to find out the interest level and costs involved are so that in the future, this could be a kit that would be available through the Honda Club Store.


Thanks for reading another huge post from me!
 

·
Registered
Joined
·
6,238 Posts
This has a lot of potential for the performance minded members.

I have often thought about a similar setup.

My question IS ::: What direction is the air flow on the hood at speed?

The Element has a large flat windshield. In some cases, my Isuzu trooper to be exact, the air flow is reverse flowing. ( That was also the case on my 1970 Pontiac Trans-Am.) Have you done any tape/string flow tests? Does the high pressure area build up with an aft for forward flow? Before you spend time/money for production, I would prove the high pressure point ( area ) on the Element.

I understand that a high pressure point, is just that. An area of high pressure. So this modification would no doubt prove to be an improvement. However, to make as effective as it can possibly be, the opening must be pointed in the direction of the natural flow.

Just a thought for you.

Thanks for bringing your expertise to "bear" on this mod. :D

Your time and effort is much appreciated !!

Dom
 

·
Registered
Joined
·
108 Posts
Discussion Starter · #3 ·
Air flow considerations

Thanks for your well-thought-out post, Dom.

I initially picked this position for the scoop because of the fact that it was the position that made the plumbing the easiest. After I removed the trim for modification, I drove a few days with the trim sitting half-done on my kitchen countertop. I noticed quite a bit of wind noise, so I reasoned that the flow over the wiper area may be a little more turbulent and not as attached as I had presumed.

I went ahead and got some dark honey and diluted it a bit to get the desired viscosity for an aero test. I thought about doing this with tufts on the hood, but I thought cutting all the little ribbons and taping them down would be a royal pain.

At very low speeds, the flow is non-laminar as you'd expect as the air slips over the front edge of the hood from the stagnation region just in front of the grill/headlights. At speeds above approx. 20mph, though, the streamlines go pretty much straight up the hood surface and stay well-attached and laminar. The little bit of aerodynamic funkiness I observed involved the flow leaking out to the outside over the fenders as it neared the windshield. It seems like the little indentation in the center of the hood design causes a very subtle pressure buildup that actually helps nudge some of the outside airflow over the edge.

Anyway, as it were, the first prototype scoop seems to be in a good position. It's not centered, as it is offset toward the driver's side, but it is not located so far off that it enters the region of escaping flow. I think it's more or less in the best position feasible if I plan on keeping it low and against the hood. It is possible, however, that if I extended the scoop so that it's sort of mounted on an aerodynamically-shaped pylon that pops above the hood a few inches, (more like a snorkel now) then it would be able to grab some air from the freestream that's unimpeded altogether.

If you've got any ideas, please PM me or post them. I'm probably going to work up one or two more versions, so I have some room to experiment!
 

·
Registered
Joined
·
6,238 Posts
Intriguing use of an all natural substance! I commend you on your ingenuity.

I was just outside taping String to the hood. I'm using painters tape, not duct tape.:) I will test the flow characteristics this afternoon. Interesting that you found an air leak in the stream. I will add some string to the area you described, just for the fun of it. I'll try to take some Photo's of the string, at differing speeds. I'll post them so you can see what I found first hand.


Dom
 

·
Registered
Joined
·
108 Posts
Discussion Starter · #5 ·
Hood airflow

I'm sorry if I made a misleading statement- There's not really any weird air leak going on... I was just trying to explain that the flow has a transverse component as you get closer to the fender edge.

Have fun with your tufting!
 
1 - 5 of 5 Posts
Top