webby459

iTrader: (8)

Still thinking out loud. What if you thin out the canard a little in the direction lateral to the car. Then bring the leading edge either close to or touching the deck of the splitter. Then slope or rake the canard to try to blend it's trailing edge with the flare as much as possible within the rules.

Still fixated on trying to smooth the flow around that big meaty tire, especially below the flare. Anyone have a wind tunnel?

Chris Swearingen

iTrader: (1)

I like the idea but .....

Is eliminating the tire drag a worthwhile trade off at autocross speeds? I spend a lot of a run with the tire turned anyway, so there is likely a lot of the tire that will be "out in the wind" even if I could effectively shield it in a straight line.

Next year when I cage the car and go faster and straighter for longer it may be more of an issue.

Keep the ideas coming

bellwilliam

iTrader: (1)

it is not tire drag (at autocross speed) as much as the lift generated by tires. it is true that tires are turned away. but with tire spat, instead of 100% of tire treads not shielded, you have may be 50% of tires shielded.

as you know, at autocross speed, it has to be a BIG wing, and BIG splitter for it to matter, even then, very little. canard really does nothing at these speed imo. it doesn't do much at higher speed either (100mph). they are used for tuning.

Chris Swearingen

iTrader: (1)

How do we use them for tuning? The appear to me to be fixed. I would have assumed that they and the splitter were both "set" to produce the most downforce available and that the angle of attack on the rear wing was used for tuning the balance. My "top speed" in second is going from 69 to 74 mph with the gearing change. So we don't see 100, usually closer to 45 but on occasion the forces do build.

bellwilliam

iTrader: (1)

tuning as bigger or smaller canard. some race car use fender size as a tuning device, but it is for 100MPH+ adjustment. I doubt anybody can feel a canard adjustment at 60mph.
Imo, canard adds down force in a Miata, not by the force generated by the device, but from acting as a tire spat, that blocks out air hitting bottom of tires, creating tire lift (which is worse than body lift).

in your case, I would design the canards to block out as much of front tires as possible. both to the side and bottom if possible.

turotufas

iTrader: (7)

One of my favorite images from SCC. Aint picked up modified yet, maybe next year. GRM is #1 right now I think.

I like the way you think. I never considered the effect that the tires have on the aerodynamics of the car due to them sticking out behind the bumper.

Midtenn

iTrader: (15)

You've also got to remember that there needs to be support behind the canard. If not, all the force on it is just going to translate to flexing the bumper cover.

j_man

Modified is not SCC. SCC went online - here is their new web site:
www.motoiq.com

thagr81 us

iTrader: (5)

Thanks for the above link... Didn't know they moved to that site (well quite a few of the writers/editors).

turotufas

iTrader: (7)

SCC was totally liquidated. Modified got a few contributors and things like the USCC. So its not quite as gay as it used to be. I still refuse to read it do!

That website is cool as **** though. Reminds me of my Nissan days. Eric Hsu, Dave Coleman, and Mike Kojima. Awesome!

bellwilliam

iTrader: (1)

not just from sticking out behind bumper. but air hitting tires from underneath, and lifting tires off the ground.

here are some ugly canards, but idea is to use it as a tire spats.

front tire is 13.1% of total drag:
http://autospeed.com/cms/A_2455/article.html

an article on dive plane
http://www.reverie.ltd.uk/Downloads/Aerobytes-Oct08.pdf

albumleaf

iTrader: (7)

Yes, flow at the surface of the canard is effectively zero, but at that speed the transition between zero and the "free stream" is going to be tiny. I don't buy that bit.