how well your Active Aero Performs

[MR2]

Taken from another thread, pictures re-linked and fixed etc.


Guys, remember the wind tunnel tests of a 2nd gen 3000GT VR4 with Active Aero a board member did way back?

Well, I was trolling around evolutionm.net and found out a magazine tested an euro spec EVO and a STI on the wind tunnel. Compared to the results of the 2nd gen VR4, I found it very interesting and decided to combine these.

Both the VR4 and EVO/STI wind tunnel tests were done at the same airflow speed. SO THE RESULTS FROM BOTH TESTS ARE COMPARABLE!


Before posting the results, here are some testing pics:

Airflow over EVO front end:
http://3000gt.com.au/car/Active%20Aero%20Performance/6506-Active-Aero_files/evofrontflow.jpg

Airflow over STI front end:
http://3000gt.com.au/car/Active%20Aero%20Performance/6506-Active-Aero_files/stifrontflow.jpg

Airflow Around 1st Gen Front bar AA Off
http://3000gt.com.au/car/Active%20Aero%20Performance/aaofffront.jpg

Airflow Around 1st Gen Front Bar AA On
http://3000gt.com.au/car/Active%20Aero%20Performance/aaonfront.jpg





Airflow around EVO rear wing:
http://3000gt.com.au/car/Active%20Aero%20Performance/6506-Active-Aero_files/evorearflow.jpg

Airflow around STI rear wing:
http://3000gt.com.au/car/Active%20Aero%20Performance/6506-Active-Aero_files/stirearflow.jpg

Airflow around VR4 rear wing, Active Aero OFF:
http://3000gt.com.au/car/Active%20Aero%20Performance/aaoffrear.jpg

Airflow around VR4 rear wing, Active Aero ON:
http://3000gt.com.au/car/Active%20Aero%20Performance/aaonrear.jpg



and, here are the results :


http://3000gt.com.au/car/Active%20Aero%20Performance/6506-Active-Aero_files/evostidownforce.jpg

Compared the numbers to the VR4's:
The left cars are with Active Aero OFF. The cars in the right are with Active Aero ON.
http://3000gt.com.au/car/Active%20Aero%20Performance/kkk.jpg





EVO/STI numbers:

Red arrows represent lift/downforce at air flow of 144km/h
Blue arrows represent lift/downforce at air flow of 200km/h
This image has been resized. Click this bar to view the full image.


So, both cars have HUGE amount of front lift at 200km/h, and EVO has small amount of lift on the back as well while the STI has good amount of downforce on the back.

Before you compare the results to the VR4's...
THE COLORS HAVE NO CORRELATION BETWEEN THESE PICS. COMPARED THE RED ARROWS OF THE EVO/STI PIC TO THE VR4 PIC LABELED 144KM/H, AND THE BLUE ARROWS OF THE EVO/STI PIC TO THE VR4 PIC LABELED 200KM/H.


With the AA ON at 200km/h, the VR4 has 4 times less front end lift than an EVO, and almost 5 times less than that of a STI!

On the back, the VR4 has SAME amount of force it had on the front end, downwards. (Downforce). EVO still has LIFT on the back, and the STI has huge amount of downforce on the back. (Over 3 times of that of a VR4). But what would you rather be driving at 125mph, a car with HUGE amount of LIFT on the front while having HUGE amount of DOWNFORCE on the back, or a car that is statically stable by having zero lift?
Notice how our cars still have only half the amount of lift EVO/STI has on the front end with AA OFF (That rearend lift does look scary though )


My Conclusions:

1. Active Aero is not a gimmick. PERIOD.
2. There is a reason our cars don't resemble econoboxes


Plus, it hurts to think that my 97 VR4 with hoop spoiler and no AA is probably the least aero-friendly model of the 3s family


By the way, the numbers are in newtons. (1N = 0.22lbs). Plus. these pictures are NOT MINE. I only combined and interpreted the results in my own ways.

[GTOJOE]

Makes me want to fix my rear wing LOL.

[MR2]

interesting how bad the EVO and STI are aye...you'd think with those MASSIVE rear wings that they'd do something, I was at a car meet today and took a look at alot of the wings floating around, 99% of the stock ones don't really appear to offer much downforce at all.

[GTOJOE]

yeah didn't expect that. I wonder how much difference a front splitter would make on both of these. The EVO spoiler would prob work better if it was angled down a bit at the front. Interesting how much better the STI is over the EVO.

[DocWalt]

Was this the translated Russian article?

There's a reason that Mitsu went with the Vortex Generators on the Evo's :p. The X wing is designed to not need one, but now it takes up even more of the rear view mirror, lol. I have an article about the X's aero stuff if anyone wants to nerd out with that.

[green-lantern]

Makes me want to install AA on mine. I don't think the evo and sti weren't really designed with aero in mind, I'm sure it's not as important as other things on a rally car.

I don't think I've driven a car that feels so good as ours at high speeds.

[MR2]

Was this the translated Russian article?

There's a reason that Mitsu went with the Vortex Generators on the Evo's :p. The X wing is designed to not need one, but now it takes up even more of the rear view mirror, lol. I have an article about the X's aero stuff if anyone wants to nerd out with that.

yep, from the russian one (I had to dig it up to relink the images)

if you have evo x data post it up!

[DocWalt]

http://img801.imageshack.us/img801/7278/page0001n.jpg

http://img251.imageshack.us/img251/2042/page0002o.jpg

http://img21.imageshack.us/img21/1561/page0003t.jpg

http://img863.imageshack.us/img863/4513/page0004o.jpg

[Markingtime]

Looking at the air flow over the rear wing on all of them I can see why the STI does so well. The wing seems to attack the air flow dead center on the STI, air flow looks like it is going under the Evo wing, and I think the VR4 wing would do better if it was mounted a little higher or if the wing was a little longer so the tip would get higher into the airflow when deployed like the Bozz Speed design. BOZZ SPEED ---ƒp�[ƒcLineUp--- (http://www.bozz.co.jp/parts-english/aero/gto-rearwingsupport.html)

[J. Fast]

I remember reading about the aero study when they added vortex generators to the evo a few years back. Here's the entire series. It was amazing to see how much more stability the car picked up when vanes were added to the undercarrage.

Auto Speed Aero 1 (http://www.autospeed.com/A_3058/cms/article.html)
Auto Speed Aero 2 (http://www.autospeed.com/A_3059/cms/article.html)
Auto Speed Areo 3 (http://autospeed.com/A_3060/cms/article.html)
Auto Speed Aero 4 (http://autospeed.com/cms/title_Blowing-the-Vortex-Part-4/A_3061/article.html)

[reallyxxxxxxloud]

I've pulled my Active areo off for the looks but in reality I dont brake the speed limit that often (by much lol) so I dont really care.