E30M3

It's EZ to get the drag information for given installed parts. Just do a coastdown test. Over high and low speed ranges. (Note that this is not the same as downforce). Try this out:

http://www.race-technology.com/WebPage/Uti...tDownCalcs.html

You do this on a dead flat straight road on a nonwindy day with the shifter in neutral. You wind up with your CdA and rolling resistance values. Low speed rolling resistance won't change with a wing but CdA will. CdA is "Cd" or coef of drag, times "A" or frontal area. You can use other formulas to get the actual drag force at various speeds. You can try different wing angles to see how much drag changes. Again we are not measuring downforce, but drag.

Note that it's important to keep the car balanced. You wouldn't want to have a lot of antilift effect at only one end of the car. Often you wind up with a situation where the speed increase on the straights may drop due to drag but so do your lap times, since the cornering is improved. I'd like to see the values for top up/down on the s2000. Sometimes wings can be tuned a bit...adding a Gurney flap, adding a small spoiler to the trunk lid under the wing, end plates, etc. Besides angle/height... Most street type cars never achieve true downforce, rather they experience less lift.

There is also a Palm version:

http://www.race-technology.com/WebPage/Uti...astdownPalm.zip

Stan

TeCKis300

[QUOTE]Originally posted by jzr
Everything I've read suggests locating the wing at least one, but ideally two, chord lengths away from the nearest part of the body to minimize this effect.

sfphinkterMC

jzr,

i 've picked up the JSP wing as well....test fitting to the trunklid so far good...can't send pics for now since my laptop crashed at Buttonwillow (but i didn't). BUT its a near perfect fit for
the trunk straps of classic carriers trunk rack. i will fabricate side
plates to adapt. This will give me complete adjustment fore-aft, height, as well as fine angle(the included plates have a 3 hole angle adjustment affair)....... if it can hold a Kuhmo V700 mounted
Mugen MF-10 at 142mph it should hold the wing, just don't follow to close on initial testing....safety wire please.
also, as suggested i will try to do measurement testing with the race-tech GPS data logger and their performance meter.
after all that, you can build me the cockpit adustable remote servo "dynamic aero-inclinometrol"

docofmind

[QUOTE]Originally posted by jzr
[B]
Not too bad looking a piece, I guess...I'd like to see it a bit higher than 10" off the deck, with larger end plates.

sfphinkterMC

55"w, 10" h
what do you think? ......nearly flawless?! those taiwanese can sure mold
carbon fiber, yep.
can you recommend a fabricator or shop in the valley that can make me some aluminum side mounting plates to go on the bottom of the strut mounts....

Mike Schuster

jzr, on the RM Racing dam. I would expect by itself it would make things looser at speed: less lift -> more grip at front. And the amount of additional looseness might be a gauge to its effectiveness. What did you feel when you tried it? I agree a lowered car would make it more effective, but did you feel anything at all?

jzr

That's a toughie, as I have taught myself to ignore as much as possible the infamous "butt dyno". Buuuuuutt....having said that, the car did feel pretty loose at Big Willow. At Thunderhill with the same tires and splitter on it felt okay. I seem to recall we were running about the same lap times...putting aside my sloppy driving, how did the car look to you? I did go through turn 8 a couple times with the steering wheel pointed the wrong way, but overall it still seemed reasonable. Handling balance felt about the same as my previous two track days in Pahrump, with the same suspension setup, but no splitter and 225/245 A032Rs.

At Big Willow it stepped out on me in turn 8 in a big way. It could have been my shocks wearing out, or the picky tires getting too hot, (or - - driver error!) but it did seem like I was fighting oversteer the whole day, including the triple tankslapper coming out of turn 9 at about 95. Could it have been the higher speeds at Willow causing the splitter to have more of an effect? I want to believe...

I'm used to racing the car with a larger front sway bar than I had those days. I think I would've been faster at both tracks with the bigger front bar - the front never seemed lacking for grip. But with the 225/245 tire stagger and stock suspension it's something I've come to expect.

Should have done one session on one of the days without the splitter, to see if there was any difference - that's the only way to really tell. Perhaps if the opportunity presents itself in one of the upcoming track days. Still have the splitter here in my living room, sitting next to the extra trunk lid, and swaybar, and exhaust system, and...

sfphinkter, are you coming to 12/13 SOW event? I want to see this winged creature of yours.

Any board sponsors/companies reading this want to lend me their biggest, baddest wing for one day of on-track testing? Promise, I'll return it as soon as I'm done...

vapors2k

[QUOTE]Originally posted by jzr
[B]That's a toughie, as I have taught myself to ignore as much as possible the infamous "butt dyno".

jzr

Even less so without a rollbar. 120 is pretty fast, what kind of times do you turn there?

And why is turn 8 always the nasty one (THill, Big Willow, Laguna...)? If I ever build a track, I'm going to skip turn 8 and keep turn 13.

S2kRob

Have you thought of running a rear diffuser instead of a big-ass wing?