how to help my matrix part 2 (front end)

[Cd]

Originally Posted by Weather Spotter

My 14yr old sister calls it the platypus car .

That is exactly the first thing that I thought when I saw the car.
I didn't mention it out of courtesy .
( I was even going to post a picture )

I'm really surprised that the opening wasn't large enough. Bassjoos gets by with only the gap opening from his hood.
Is there a blockage somewhere, because I personally have run my Civic blocked with less air than that.

[basjoos]

Originally Posted by Cd

I'm really surprised that the opening wasn't large enough. Bassjoos gets by with only the gap opening from his hood.
Is there a blockage somewhere, because I personally have run my Civic blocked with less air than that.

I longer use the gap opening in front of the hood. That was before I installed the adjustable grill block in the bottom of the nose. These are two 10" x 3" openings, but I rarely need to have them fully open.

When designing modified cooling systems, you need to lay it out so there is a pressure differential across the radiator when the car is moving. You need a higher pressure at the inlet combined with a lower pressure at the exhaust so air will move across the radiator when the inlet is open. In the aerocivic, there is the ram air pressure of the oncoming air at the inlet and the lower pressure is created by the squirrel cage blower effect of the rotating front wheels in the wheel wells (the underside of my engine compartment is completely paneled so nothing is exhausted there).

If you are having problems moving the air across your radiator and you have the typical open bottomed engine compartment, you could add a small thin air dam strip just ahead of the engine compartment opening like the early 90's Chevrolet Camaro used to create a pressure differential across their radiator.

[Weather Spotter]

Thanks Basjoos, the added hole worked just fine today, and I left the closeable half shut all day. When I was under the car yesterday I noticed that my furnace grate still had all its louvers in place and angled to both edges. I think I was just adding to much resistance to get enough air through it. I cut off the fins and just kept the open and closing parts

Also I have an belly pan under the engine (some air can get out the back but not much) so the air is forced out into the back half of the wheel wells.

The first opening is 4x13" and the furnace grate is 3x13" the second hole I made is 4x 10.5". this gives me 42sq in always open (except in winter I plan on covering this hole) and another 40 or so that are operable. all in all its the same as I had before with my two grates in my lower grill.

I am planning on making a metal cover for the second hole and using that once the summer heat is gone say mid sept-may. this will give me control of airflow for most of the year and only when I need more then one open I will take off the cover.

[Sven7]

Nice progress real fast! If you're going to 'glass it you might be better off creating a new mold out of styrofoam insulation or something, just to make it smoother. You could make a fishbone model and sandwich insulation between the "bones". Sculpt the extra until it resembles the shape, fill it and sand to a paintable surface, then glass it.

I'm getting ahead of myself. Anyway, what kind of MPG do you see going 50-55mph?

[Weather Spotter]

[QUOTE=
I'm getting ahead of myself. Anyway, what kind of MPG do you see going 50-55mph?[/QUOTE]

With or without tail wind

Steady state driving:
With a light tail wind I can get 54-58.
No wind 52-56
light head wind 50-54

Adding the coasting I do from the given speed:
light tail wind 1-1.3 miles of coasting (depending on wind speed)
no wind 1-1.1
light head wind .8-1.0

my normal commute is made up of 19 miles of back roads (55MPH speed limit) and 3 miles of city (4 lane 40 MPH speed limit). On the way to work the city roads are empty and It only slightly hurts MPG. on the way home its busy and the traffic lights suck (three or 4 are blinking yellow on the way to work) but on the way home you are going to get 2 red no mater what you do and 3 or 4 is not uncommon. Half are sensor operated and no or short crosswalk signals, the rest are timed but the timing is a forced stop. After 18 months I have the cycle down and its a nasty section to do.

[Weather Spotter]

here is the front pic with both holes as promised:


My sister made a tong piece but it is only for one hole, so its out of proportions, I need her to make a right size one then I will post a pic for comments

[Weather Spotter]

I still have the modding bug, I am thinking about front wheel covers. I like the roller idea, might see if we have some surplus ones at work.

Two issues:
rubbing, what have others found over time?
Snow, has anyone done this mod and used it through several snowy up north winters?

Whats the expected MPG gain from it with and without smooth wheel covers?

Second idea/ question is side skirts, what do they do for you? I am unsure as to the aero gain verse snow drag/ build up. Ideas?

[sheepdog 44]

I've been really thinking about that too. Possibly even before a boatail, i was gonna grill block, windshield wiper deflector and front wheel skirt.

I like the idea of a front hinged design. My biggest issue with top hinged is air getting in the front and not being completely sealed. Maybe it's a non issue? No air getting in the front, and the air moving past sealing the trailing edge to the car. The problem is clearance in a sharp turn. Top hinged is fine, but front hinged has the angle between hinge and wheel to sharp. Been designing several double hinged solutions.

These are my ideas for the frame to be skinned in coroplast in a way that allows it to bend and curve around the frame.

One is double hinged at the front like this:
so it pushes the fairing at a parrelel angle outwards, while the front still deflects air around it.

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Second is hinged at the front double hinged at the middle:
The middle section folds completely flat when the wheel is not turned, and when turned the middle section allows complete clearance of the rim.

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[HydroJim]

When I build my Front Bumper, I'm going to increase the width of the bumper wide enough to cover the front wheel skirts to ease the transition of the air to the skirts because they inevitably stick out of the vehicle and if air can reach them more smoothly, I figured a higher benefit will be found. Maybe it's something you can integrate into your design since you're in the modding spirit.

[Tango Charlie]

You're gonna have to re-name your car "Perry".



For front wheel skirts, you could use the white plastic cutting board material instead of rollers. It's tough, slick, and I bet it wouldn't abrade your tires much at all.