AERODYNAMICS!!!

Typrus · Post by **Typrus** » Thu May 05, 2005 9:00 am

Ok, I have no idea what the wriggity thing is for.... Ummmm.... Yeah..

Those are just a few of the photos I took of stock HORRIBLE aerodynamic places. I have many more, just have yet to host them.

Now the mods (In Styro-Vision!!) That could be done to remove the air "scoops" that are all-too-common in the design.

If we could make less flat spots and "scoops" for the air, we could get much better fuel economy and top speeds!

GTSSportCoupe · Post by **GTSSportCoupe** » Thu May 05, 2005 9:28 am

I would say that the best things a person could do is lower the car by about 3", put in a nice big front air dam, and convert to the late tercel front grill/head lights. Would make a huge difference on the highway, but would suck for 4wding

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Typrus · Post by **Typrus** » Thu May 05, 2005 6:59 pm

I don't want to screw with the 4wd capability. Well, not on one of them at least.
On the one I am dreaming of doing a TDI conversion for, I might get it running as low as I can w/o having to take speed bumps at special angles.

How could we execute something like these? FiberGlass? Molded plastic? Wood??

clbolt · Post by **clbolt** » Thu May 05, 2005 8:46 pm

GTSSportCoupe wrote: I would say that the best things a person could do is lower the car by about 3", put in a nice big front air dam, and convert to the late tercel front grill/head lights. Would make a huge difference on the highway, but would suck for 4wding .

Lowering the car would be fairly easy, although 3" would be a bit extreme. I wouldn't swap to the later headlights, simply because of the decreased light potential (US-spec composite headlights suck, pattern-wise). A set of headlight covers is fairly easy to cut from lexan sheet, at a cost of a couple of bucks.

As for the air dam, the biggest obstacle to one on the Gen2 Tercel is the lack of a front valence panel. It can be done, but it has to be mounted to the bumper cover, and it's generally ugly.

As for the aerodynamics of the mirror, the one on the right side can be easily eliminated altogether with the use of a block-off plate from a base Tercel hatchback. As upright as the windshield is, I'm not sure the mirrors are all that much an addition to the Cd at the speeds a Tercel is capable of.

At stock ride height, a more useful aerodynamic mod would be as full a belly pan as could be fitted around the suspension and driveshaft. Of course, that'd be murder on the offroad capabilities.

Typrus · Post by **Typrus** » Thu May 05, 2005 9:50 pm

Well.. What of quick-release systems? Something you could go pull 3-5 hidden pins out of to take off and throw in the back?

Right now I wish I had AutoCAD....

Lexan or PlexiGlass? How much interference would be had with either? In terms of projection.

Typrus · Post by **Typrus** » Thu May 05, 2005 10:40 pm

What thickness is good? Look here.
<a href='https://secure11.nexternal.com/shared/S ... =386207222' target='_blank'>https://secure11.nexternal.com/shared/S ... 6207222</a>

I wonder if it would distort the beam? Would it work with an H4?
If you put a few breath hole in the lexan, the light would be colled, keeping bugs and mud off it, extending bulb life?

What can be used for a windshield wiper cowl, or a filler for the blank spot where the air rushes up over the windshield? Pics should be up for those.

clbolt · Post by **clbolt** » Fri May 06, 2005 12:00 am

Typrus wrote: Well.. What of quick-release systems? Something you could go pull 3-5 hidden pins out of to take off and throw in the back?

Right now I wish I had AutoCAD....

Lexan or PlexiGlass? How much interference would be had with either? In terms of projection.

Quick release for the headlight covers, or for a belly pan? Dzus fasteners would work for the belly pan, Velcro works well for the headlight covers.

Plexi is too brittle to use for headlight covers. Lexan works well, but any type of plastic covers will distort the light somewhat. I used Lexan covers on my 81 GLC Sport in high school, with Hella H4s. I generally tried to remove them at night, but the covers didn't melt when I didn't. I also had a smoked pair I used only in the daytime. I pinstriped the grille bars in red, and striped the covers to match. I think the thickness was 3/16".

Now to open another can of worms. A real obstacle to the Tercel's aerodynamics (and there are many) is the turbulence caused by the air coming off the back of the roof. What the wagon really needs to correct this is a wing, fairly flat in profile, that would continue the line of the roof (slightly elevated) far enough past the back of the car that the turbulence wouldn't create drag on the back of the car. This isn't an issue in the real world. The wing would end up looking like something on one of those nightmare custom Japanese vans.

Alright, here would be my plan for the world's most aerodynamic Terk wagon... 2WD, lowered 2 to 3", e-code bumpers, custom front air dam, full belly pan, blanked grille, headlight covers, shaved side mirrors, remove windshield trim and replace with smooth low-profile rubber bead, shaved rear wiper, flush-mounted side windows (would require extensive engineering or hard-mounted Lexan windows), no side moldings, no drip rails, and the aforementioned roof spoiler. If the Terk had smoother airflow over the windshield, I'd shave the front wipers and go with Rain-X (My Merkur XR4Ti would completely clear it's windshield at any speed over about 12mph). Shaving the door handles and hatch handle would also help. You'd want to run the narrowest possible tires for less drag and lower rolling resistance.

Of course, most of this would be ridiculous for a street car, but great for a land speed record car. Anybody up for a 200MPH Terk wagon?

clbolt · Post by **clbolt** » Fri May 06, 2005 12:02 am

BTW, you could also fabricate Lexan covers to smooth out the front bumper lights.

Typrus · Post by **Typrus** » Fri May 06, 2005 6:45 pm

I know any plastic will distort, just to what extent? The hope would be to angle them to the side to channel air off to the exterior flow.

Drag is caused by a lower pressure zone, pulling back. If we could fill said empty zone, drag would be reduced? Something like a downward air scoop, meant for filling the void, and minimal uplift? How about side-mounting channeling vents?

I'm not worried about the windows. Yes, they do drag it up with the current indentation, but its nothing horrible. Nothing worse than a lot of cars out there. Though I could come up with something to help with that.

Rear fender-skirts?

Quick-release for the belly. Though the plastic might need it too.

How to cowl the wipers?

clbolt · Post by **clbolt** » Fri May 06, 2005 7:56 pm

Cowling the wipers would be fairly easy, just make a cover like those plastic bug guards a lot of people put on the hood of their pickups.

Mac · Post by **Mac** » Fri May 06, 2005 8:20 pm

buy those new low profile wipers they have at canadian tire now, those would do wonders for aerodynamics, and as for mirrors, the mounting holes are the same for a mid 90's celica with the M3 style mirrors, i measured them at a J-yard, only thing is the celica mirrors (the ones i saw anyways) were power.

Typrus · Post by **Typrus** » Fri May 06, 2005 10:45 pm

I'm in Colorado, USA?

Can Lexan be formed that easily, or would something else suit better?

takza · Post by **takza** » Sat May 07, 2005 5:43 am

I know you can put a sheet of plexiglas in a home oven and if you get the temp just right...it can be formed anyway you want. I forget the temp needed...do need to worry about the surface getting marked while it is hot.

Any large city will have a plastics place that sells it in sheets..tubes...etc...and will have the technical info.