Hello folks,

I am currently a mechanical engineer senior at MIT and am taking an instrumentation class in my final semester. In this class, each student gets to choose a topic of interest to research, with a focus on quantifying something. I want to measure the increase in downforce from an adjustable GT style wing.

I plan on making custom standoffs for the airfoil that I can easily attach instrumentation to, and measure the deflection (strain) of the structure to find the downforce data. I will overlay this data with the speed of the car, taken from the ecu/vss.

I am posting in this forum because I am curious to see if anyone has taken this data already, for any kind of aftermarket gt wing.


Secondly, I would like to see if anyone has a spare trunk/GT wing that I can get locally to drill holes into, or if anyone has a s2000 trunk with a GT wing on it already to loan for two weekends or so in the name of science.

If anyone can help me out, I would be happy to document other performance parameters of interest to you like drag, lateral acceleration, etc. for your troubles.

Thanks for your consideration.

-L

 

Sucks to be you!

There are a lot of real-world uncontrollable variables that make it hard to gather this data on the car as well as can be done in a wind tunnel. If you can get wind tunnel time over in Bldg 17, I would go that route.

 

The wind tunnel is rarely used nowadays, and very hard to get time on. Most aftermarket exterior parts have no data to back them up, so it would be interesting to piece together real world, in-use data that gives some deeper understanding of our modifications.

GT wings in time attack/ road race tracks are pretty common, so maybe someone has done this already.

 

APR performance has some CFD data on their GT wings. You can find them on the APR website.

My recommendation is also the wind tunnel route if you have access. I am currently doing a study on downforce data generated by a GT wing, front splitter, rear diffusor, and canards for a 1:10th scale model in a miniature wind tunnel.

Hope it works out for you. Good luck.

 

If it's rarely used, why would it be hard to get time on? That doesn;t make sense.

But maybe there are other tunnels you could use? When I was there, I remember we had a smaller tunnel in the Aero Astro lab building too. Maybe Course 2 has a tunnel? I don't know.

Anyway, it's not going to be as easy to get clean data on the car as you may be thinking it will be.

As for whether any of us have such data, it's doubtful. Some of us have tried to get data for stuff like this, but mainly it's pro outfits who would be taking this sort of data, and that's not going to be given away for free.

 

I'm very interested to see what you come up with. APR has data on their wings, I have yet to see any data of a Voltex wing though.

Are you going to perform any studies in relation to lift and drag due to gurney? I've read that on single element low reynolds number wings, up to 2% chord gurney has no drag penalty, while increasing lift by as much as 25%.

Have you locked down what type of airfoil you want to study (single or multi element), or is it pretty much what ever you can get your hands on?

 

what application?

 

I have zero engineering education, and I don't drive an S2000. However, I did a fair amount of testing with a home-made wing I built for my old 911. I was never able to get my head (or my budget) around strain gauges, so I got a pair of 1995 Lincoln Continental ride-height sensors to feed into my data logger, and then tested a handful of aero components in both high-speed straight-line tests (out on a lonely stretch off freeway near Mojave) and also at my local track. I also did some wind-tunnelish tests with wool tufts and a handful of camera angles to study air flow characteristics of my car and what wing angles produced what separation under what conditions. I don't know if reading any of my stuff would be helpful, but I had a lot of fun doing it.

Sometimes, I'm sure I looked pretty clowny to anyone who happened to drive by. My idea for a front wing was patently ridiculous.



But the tuft tests were really useful, especially when they showed that my higher-than-roofline wing was still getting 11-degree airflow where most people would assume it would be parallel with the ground.





I was able to get repeatable and distinct ride height changes for 4-degree drifferences in my wing's angle of attack. It was also interesting to see some cantilever-effect front end lift as the result of using my big (home-made) rear wing.

 

Hi PBE,

I am extremely interested in your findings as many of the members here. I have a friend who used to be involved in racing and he has mentioned how rather flimsy some of the JDM aftermarket wings look.

Example being the wings used in racing are very robust and u could have people sitting on the wing and it wouldnt really flex at all....whereas if you put one hand on the midsection of a Voltex Type 2 Wing ( http://www.voltex.ne.jp/catalogue/2008_01.pdf ) u can actually see it flex up and down.

I would like to suggest a finding of wing flex under high windspeed if it falls into the area of information you would be exploring....

 

Listen to Mike...he has really been EXACTLY where you are.

But, if you can't get into the university windtunnel, it might actually be easier to build your own, calculate the Reynolds number of the actual GT wing and make a scale airfoil to match for testing in your windtunnel. I'm not sure that can all be done in a semester...but...

And Mike is right, live testing on the car has too many variables to create sufficient valid data to draw a conclusion.

But if you want to validate the data you collect, you might find the NACA number for the airfoil you are testing and use an app like JavaFoil to create the lift coefficient plots to calculate expected downforce for angle of attack.