I know the sport package (offered on the 86-88 cars) will affect the aero of the car very good (CoD=.29 vs .31 and CLf=.08, CLr=.07 vs .14), but does anyone have the numbers for the wing on the newer cars? Is it actually functional (besides adding downforce, how does it help drag?) or just pretty? I'm pretty sure it's functional, but I would like to see some numbers if possible...

 

I have a book on rx7's and they say that the smaller on works better than the larger one. I don't know if they meant that it lowers drag, or helps in down force. I would gues that just it lowers drag.

 

i dont think ive seen any info on the s5 cars, but i would bet the large wing is both more drag and less down force

mike

 

i'd say more drag and more downforce. if you notice they actually designed it to overhang the rearend a bit. probably trying to pick up cleaner air due to the dead zone over the hatch.

 

i dont think the wings on the Rx-7 do anything. they just look nice.

its to low, and not very agressive to do anyting, other then making a very small amount of drag. just look where its at. totally not functional. I would guesstamate that if it where functional and it had that profile, it wouldnt be effective untill 150+mph....

come on, theres very few cars today that have functional wings that cost less then $100,000

 

OC, I know that the wing does something, all of the wings do. They need not be aggressive to work, I hardly call the sport kit for the S4 cars aggressive, BUT they do affect the aero VERY MUCH. Everything is functional, it's just not always gonna do what you want. I'm pretty sure that the S5 wing does increase downforce, but I'm guessing it also increases drag unlike the S4 wing which increases downforce AND lowers drag. If you guys find anything though let me know (specifics).

 

Chances are it's not the S4 spoiler that decreases drag. It is PART of the sport kit, which includes side skirts and a front air dam. THIS is what decreases drag (by reducing underbody turbulence and airflow). The sum total of drag is lower, but if JUST the spoiler were installed, drag would increase.

 

I don't think so, the small wings that the manufautures put on hatchbacks will drop the cd. a few points at 70mph. you would be very suprised how a very small thing will make such a big change in the arow of a vehicle.

 

Why would Mazda add a more weight to a car they spent such a great amount of time trying to lower the weight, just for looks... Thats just doesn't sound like Mazda RX7 I own.

 

Oops...that's what I meant to say. I was in a hurry. I meant to ask also if anyone knew what the CoD was w/out the rear wing (not that it would be smart to remove it since you lose df)? I'm sure the wing affects the CoD, but not nearly as much as the other add on pieces (it smooths the airflow over the body instead of it "dropping" off the back of the car creating more turbulence).

 

small wings help CD, i think i read the lil spoilers on saturns reduce it by .01. I'm guessing both the s4, and s5 wings help CD, and reduce rear lift somewhat, which is better, who knows? i have an s4 with aero and i like it,.. but uhh,.. i cant really tell the differance,.. i get really good gas highway milage compared to most people i guess,..

 

Lip spoilers and wings are different things. I know that lip spoilers help the CoD because they allow less air to get under the car, AND the air that does get under the car moves faster because of a smaller area (better velocity) to move through. I'm just looking to find out how the CLr is effected with the newer wing. I eventually would much rather just take some time to study the underside (currently hurting my brain I study so much) of the car to see where I could place flat panels (underbody panels) to smooth the airflow W/OUT increasing the lift factor on the car (like the Ferrari underbodies). If you were to smooth over the bottom of the car it would make GREAT CoD, but it would also increase the CLf and CLr which is the opposite of what I want. I'm looking for spots to have openings (similar to the way you would use a vent on the hood to add downforce to a car, look at the front of the 911 GT2 and the RX7 type 15th A-Spec) on the undercarriage to allow suction on the bottom of the car and still have a great CoD factor. Anythought feel free to post them.

 

you are trying to to get what is known as the venturi effect. take a good look at gt1 lemans cars of the early 90's or the r34 skyline's cf undertrays. the trick is to let the least amount of air in, give it room to expand (pressure drop), and keep it as smooth as possible to reduce drag. thus front and rear diffusers as seen on many race cars.