sc1 aero mods

[Sporty Modder]

Have you noticed a Fe differance since the wheel strakes?

[arcosine]

Not yet, I just put them on yesterday. I haven't been keeping track of the gas mileage, since the odometer doesn't work with the engine off and coasting and it takes a mile for the GPS to start working. It seemed to accelerate faster down the slope into my road, I had to brake, but it was just repaved and now super smooth. 10% of the drag on a car is from the front tires.


I don't know what rectifying effect is, but it might have to to with the body on the Probe IV is so low to the ground that the angle of the tread to the pavement is quite acute. My car rides quite a bit higher than stock due to the over size tires (2050 rpm at 65 mph).

The air flow forward of the front wheel is flowing outward somewhat because it is deflected around the body of the car. This can be seen by the streamline streaks left by dirty water drops on the belly pan underside. Also by this:



it's also interesting to watch the spray from tires during a rain on the freeway

[arcosine]

Working on the right front skirt. It's 1/16 HDPE sheet from Mc Master Carr. Note the spacer block at the center of the wheel, it's made from packing polyfoam. Needs more work before the first test drive. . It's just so hot outside, I thought Id take a break.





I think I'll paint a wheel on it...too many rubber neckers on the interstate.



There's about 3/4 inch clearance before the tire rubs.

I drove 29 miles yesterday in the tollway, 65 mph max and the skirt is still attached and no unusual rubbing sounds! There seems to be more buffeting, sensitivity to wind. Which is an indication that the flow is more attached on the side of the car. I also made left and right lock to lock turns.

[Weather Spotter]

looking good !

[arcosine]

I put the other front skirt on, painted a circle on it and filled the tank and zeroed the trip odometer. It will take a month to empty the tank.

The first time I test drove it, I ran over a curb and the skirt got under the tire and curb and ripped off the tie straps. I raised up the front an inch.

I used a heat gun to shape it.




Right trailing:


Left leading:


Right leading:

[JethroBodine]

Looking good. Love the painted tire idea.

[arcosine]

By cutting the latch I was able to lower the training edge of the rear deck by 1/2 inch and also moved it back 1/2 inch. I bent the lid corners so they fit closer the rear glass:



I am thinking of mounting the spoiler as shown in the picture. I want a 15 degree angle. One problem is it blocks part of the tail light. Do you think it would reduce drag much? It looks kind of futuristic in a 1980s sense.

[Cd]

My guess is that you will get better gas mileage if you leave the spoiler at its factory installed position.
It grabs a bit of the air that is detached and gives it a clean break.
Personally, I would just add to the length of the spoiler to meet the template line .
It's my opinion that there is not going to be that much air flowing down the spoiler in the position you have it at. I would guess that the air will be too turbulent to do much good.

BTW, I think a large amount of the 'rubbernecking' with the front wheel covers is simply due to the color.
If you painted them matte black they would not stand out as much.
You have a really ingenious design going there. It seems people are making you feel ashamed of it, but I think the fake wheel idea will just amplify this effect.
Why not just paint the front and wheel covers matte black ?

At first glance it could simply look like a car without its hubcaps .

[arcosine]

Thanks but the spoiler is not going back where it was. The template is hogwash. Half a tear drop on a plane has over twice the cd of a full tear drop in free stream. There is faith and there is science and I have no faith in the template.

[Cd]

Look at this car and blur your eyes . Does he have wheel covers on ?
Same idea.