Thanks Daniel… as he said!
I am very interested, but I am graduating college soon, then I will have to find a job. Are you the ones I would purchase the wing from? Would it be possible to make a deposit?
-Zack
You will have to email Patrick at tnd2gen@yahoo.com for more information. These are limited release and I don’t know how many are already on the waiting list. My last understanding was they were in transit from Japan.
I am NOT in any way affiliated with or set to profit from these sales at all. I thought I would make that clear since I have been understandably associated with the importation and sale of the wing and lip spoiler. Patrick (tnd2gen) is very busy and has limited access to the internet and these forums, so I help him out by answering questions so they don’t go unanswered for days or weeks before Patrick logs on again. I’ll do my best to provide the information I have, but for the best up-to-date info just send Patrick an email at the address above, as I too have become quite busy and don’t frequent the web very often anymore.
-Daniel
All the items are in, although I will be a little tied up with work dealing with Nardi/Personal for the next week or so and wont have any time to deal with the DA aero parts.
Again, any inquiries should be sent to tnd2gen@yahoo.com. As soon as I have some spare time to get all the orders filled Ill post up and get this shipped out.
Pat
Our office at Axis Engineering, where all the DA aero parts got shipped to, is moving from Irvine to city of Industry and this will move my schedule at least 1 week back. So I wont be able to take pics and ship anything out until at least May 16.
Ill let everyone know the situation when I get a chance. Please be patient, as my computer will be down also for around 1 week.
Pat
On Monday May 29, I will post up pictures and will start accepting payments.
I mentioned things are getting busy at Axis, well this week the Big
boss from FET is down from Japan and I will not be able to ship
anything out.
Shipping to the continental US will be a flat $45.00 through UPS ground.
Shipping to Canada will be a little expensive, and will depend on the
location. Vancouver is around 140$ while Ontario will be around $160.00.
Anyone from Canada is welcome to look into a cheaper way to get these
shipped, and hopefully we can arrange something.
Those looking to pick-up can do so from either City of Industry or
Costa Mesa.
Pat
Heres some pics of the DA aero parts:
USRacing Front lip:
HIRO Rear Wing:
Ill post more pics when I can get Daniel over here with his very expensive camera gear. 
NOTE: These are unpainted Black FRP. Like any other aero body parts, pre-paint prep and slight imperfections may need to be smoothed over depending on your particular final finish expectations.
That is sooooooo nice. What side skirts are those?
Skirts are Honda Access I believe.
I’ll get over there as soon as I can, bear with me, life is busy and it might take a week or two to get some time together.
When you take more pictures, can you please take some of how the clips/brackets for the wing look like. Thanks.
Sure thing. :hi5:
cant wait to order one of those wings, they look awsome!
Hey pat i’ll give you a call about that wing
how do i order one of the wings?
omfg that front lip :jerkoff:
Great job Digital Horizon of explaining the basics of aerodynamics and downforce. I myself believe in rear downforce on FF platforms. I do have a few questions which I believe have gone unanswered in the past 7 pages of this thread.
Before I proceed with my inquires, I am not looking for a flame war, and but rather I’m curious as to how I can apply your research and findings to my DA. (I’m also currently trying to complete a Mechanical Engineering major, and have inherent mechanical curiosities.)
You stated,
“…we will be adding more downforce to both the front and rear of the car, and most of the first few months of the season will be spent tuning the car’s aerodynamic balance.”
A few months have elapsed, and I’m interested if you’ve come to any conclusions. What values have you found for the HIRO wing in question? (Values such as the Angle of attack, dynamic pressures, pressure drag, turbulent airflow characteristics, flow separation points—and so fourth, and at what airspeeds were these tests administered?)
You also stated,
“I have taken the lead in the aero while Patrick is going to focus on chassis and engine upgrades (looking for a 30 whp bump for next season as well). Next year should be a very good year and we’re looking forward to tuning our way toward an ultimate goal of being [one of] the fastest DAs in the world.
…for more downforce you add, more drag is created proportional to the shape and profile of the wing/airfoil. Different shapes and configurations produce different L/Ds.”
From the pictures of the HIRO wing, it looks to me that the wing does not have any airfoil or “teardrop” shape. The trailing portion of the wing does not appear to taper rearward. Or, perhaps it’s another type of aerodynamic shape?
The upper surface of the HIRO wing, creating the high pressure area appears concave, and wouldn’t this cause a greater pressure differential, causing the layers of air sheets of the boundary layer from the leading edges laminar flow, to create an unsteadily high pressure area? (As opposed to an airfoil, where the surface of the wing creating the high pressure area is convex, to keep the air sheets together longer, and “delaying” the separation point?)
You also stated,
“Traction is needed front AND rear on a road race car, which is why there is a wing on this car and more downforce will be added for next season. Corrections with weight balance, suspension setup, and brake bias, as well as aerodynamic balance and tuning are used to balance the car so that the driver feels as little understeer as possible, since that phenomenon is inherent to FF cars. Tuning the DA chassis in particular has been difficult. I myself have only been a small part of this project for only a short time, and I have learned much about FF aerodynamic tuning from Patrick himself, and added it to my own knowledge of fluid mechanics and computational fluid dynamics to produce a sound 3D fluid flow model around the race car.”
I’m curious how downforce can be tuned, if on the HIRO wing it does not seem plausible to adjust the angle of attack? Is the mounting bolts adjustable, which allow these changes?
On the HIRO wing, there are also no tip plates, which would reduce the spilling of the high pressure area, off of the ends of the wing.
You also stated,
“I don’t understand your reasoning… how else are you supposed to attach a wing? Once again, are you saying that any trunk mounted spoiler wouldn’t be putting downforce on the rear of the car? In that case, why do all stock bodied racing series (even NASCAR, NHRA funny cars/pro stock, BTCC, JGTC, etc) ALL have wings attached to the trunk or body?”
Cantilevered wings are used in several bodies of racing. According to Carroll Smith, “Until 1973 our rear wings sat directly over the rear wheels. Then Colin Chapman figured out that, if he cantilevered the wing well behind the rear wheels it would operate through a lever arm, would push down harder on the tires, would be operating in much cleaner air, and would have a vastly greater amount of space beneath the all important lower surface. This means that we can produce more downforce at lower angles of attack and so significantly reduce drag.” (pg.91 Tune to Win, Smith)
In this sense, it seems a more advantageous position of a wing would be behind the car mounted to the rear of the chassis.
Also, with regards to Brian’s post about the rigidity of an effective wing, again according to Carroll Smith,
“Actual wing unit loadings are not excessively high—no more than 0.8 lb/square inch. If the wing and its mount are strong and ridged enough that the vehicle can be pushed by the corner of the rear wing, then it is strong enough. This means that you can make the wing really light—and you had damned well better, because it is just about the highest point of the car and is cantilevered out the back like a trailer.”
How heavy is the HIRO wing? Okay, that about sums up my inquiries. And any replies are appreciated.
-Andrew
Well I finally got around to packaging one of the wings, and it seems my shipping and handling numbers were a bit off. I had originally got a quote from UPS for arounf $45.00, but it seems the packaged wing will be oversized 1 (total dimensions are 120")
The shipping dimensions for the wing are 60x20x12 and weighs 6 Lbs. The cheapest shipping method I found is DHL, which is around 50-55$. Taking into account 20$ for shipping materials, It looks like it will be closer to $75.00 to ship these.
Anyone is welcome to look into an alternative shipping method but for now, the cheapest and safest is DHL.
Pat
Unfortunately I’m busy at work, so an immediate answer to all of your questions isn’t possible right now. I will get to all of the answers when i get more time, but apologies if it takes a few days.
In the past few months, Patrick and I have both undergone horribly busy personal lives. Patrick’s work was transferred twice in a 2 month period, as well as other personal issues that occupied some of his time. We did go to one track day and make some minor tweaks to the car to see some ass dyno effects, but nothing major. The rear chassis section of the car has been modified to accept the planned rear diffuser as well. As of today, that’s how the car sits, basically how it was at the end of last season with a few minor changes. Engine is still how it was as well.
Unfortunately, wind tunnel time is very expensive, and hard to come by. I am struggling to get a friend to somehow let me use the rolling chassis wind tunnel at his facility, but since its so expensive a time “donation” has been unattainable. The experiment test plan document is still unofficial, and will also be a part of my masters degree research if I choose to pursue it in this field. Since it may one day be published, I won’t go into too much detail, but here are the basics.
I plan on investigating the airflow characteristics of the entire body, from freestream to wake. I believe most of the work can be done under and below the rear of the car, with the wing forces adding a healthy but not the most important component of the aerodynamic force and balance. Being a relatively low powered car, there is only a certain amount of downforce that can be added before the inherent drag forces destroy its benefit… so most of the work we’re doing is to try and “clean up” the underneath and rear of the car. Not much physical work has been done admittedly… we’re just too busy. I have my work and other things to worry about, and when I’m free Patrick’s busy, the usual story. We are both driven to make it work, however, and as time goes on (and/or I start up with my masters program) we’ll get to it.
The wing and its effects are an interesting part of the aerodynamics of the car, and I’m going to rely mostly on test data as opposed to CFD models to determine benefits and any modifications we can make to improve its effectiveness. I plan on testing at several free stream velocities, 20-25 fps (low speed), 60-70 fps (moderate speeds), and 125-130 fps (high speed). With that data, I’ll be able to know which adjustments (angle of attack/incidence, possibly deck height) should be made according to which track.
All of the other tests you mentioned, though valid and very useful in an advanced analysis, are somewhat hard to test without a dedicated test model, complete with sensors and test data collection equipment embedded and/or attached to the test subject. This is the reason why aerodynamic models are so expensive, and are usually only made by manufacturers and higher budget race teams (it is also, consequently, the reason some Japanese aero parts are more expensive). I’d be happy with just aerodynamic force data and pressure distributions at those different airspeed and AOA/surface height configurations for the wing, and a basic pressure distribution on various other points on and under the body.
A flat plate is the most basic aerodynamic shape, implying that all surfaces and shapes have aerodynamic properties. The airfoil or “teardrop” shape you refer to is what yields the most efficient generation of lift vs. drag created ratio. There is also the importance of stagnation and flow separation points, leading to an investigation of stall angles and spanwise Cl generation due to pressure distribution.
The HIRO wing does in fact have an airfoil shape. Not a typical airfoil you’d see on a plane or race car, but one that appears from inspection to give a fair amount of downforce at moderate speeds with moderate AOA. This is all by inspection of certain properties of the airfoil profile, which is something you learn in airfoil selection design. This explains why the wing, when mounted (which is unadjustable) is at a relatively low AOA/incidence and appears flat at the bottom (top). At the flow conditions that this is intended to operate at (low Re), leading edge separation is not enough of a problem that a thick airfoil or large leading edge radius is needed to counteract its effects… basically meaning laminar flow at the leading edge will not separate prematurely and cause loss of lift force. At the low AOA that it is at (and therefore designed for), trailing edge separation isn’t a big factor either. Observation: HIRO engineers were designing the airfoil shape to yield moderate downforce yet minimize separation effects at anticipated operating flow conditions. Had they wanted a more agressive wing that produced more lift, you would see a more cambered profile. Had they wanted a more laminar and drag-efficient type wing, you would see a more symmetrical profile. They got a set of characteristics they wanted, and designed the shape that would give them that. “Back engineering.”
Downforce can be tuned by adding devices (front canards or rear diffusers) or by increasing the angle of incidence of the rear wing. We have tried to come up with ideas during brainstorm sessions about how to increase AOA or incidence, some of the ideas are to cut the center section out of the wing and make swivel mounts for it, change the height in which the rear of the wing is mounted, etc. Not an easy task with the HIRO wing.
Which is why we are considering a GT style wing… end plates will add to the efficiency in the generation of lift (as you stated) and also reduce the generation of drag through tip vortices. More downforce can also be had due to a more agressive aerodynamic profile, and angle of attack can be adjusted, as can surface height in order to ensure the air coming off of the roofline isn’t interfering in the wing’s freestream. As it stands, I would assume the reason the wing is at the height it is at is because they tested it and saw that it was in clean air. The fact that the DA is a hatch (and therefore the turning angle from roofline to rear window isn’t as great as in a coupe or sedan) that flow remains attached pretty well at that point and clean air isn’t too far above the trunk surface. Test results will show if this is true or not.
You must also realize that the HIRO wing was designed for moderate speed racing and/or part time street driving, not high speeds or full on professional race teams (since it was designed for a car anticipated to have about 200 hp or less), so the tradeoff between a wing that was aesthetically pleasing and 100% aerodynamically efficient MAY have been a factor in design. Not saying I agree with it, but its possible. They did have to sell these, so I’m sure marketing and target market analysis was considered. It is one of the few spoilers that actually had aerodynamic benefits at all for the DA, which is why it is on the car now and we are trying to improve on the design to maximize its effects in a semi-dedicated race car (vs. a weekend racer street car, which is what I believe it to have been designed for, thus sacrificing some aerodynamic performance in the name of “looks” or ease of install, etc.).
This is true, basic vector statics. What we are trying to do is maximize the potential of the HIRO wing to see how fast we can be with it before ditching it for a more radical wing design. Having a wing hanging off the back of Patrick’s car is not a bad idea, but having a body-mounted wing is somewhat of a technical challenge that we have taken on and want to stick with.
Not sure, I’ve never weighed it. Fairly light.
Good questions, hope I answered them in some form. I’m in a hurry and don’t have time to proofread, so if I repeated or rambled or didn’t make sense, don’t hold it against me. :salute:
Thank you for your in-depth response DH. Your efforts to explain are much appreciated. I was wondering, if you may have come up with any rough calculations of Drag HP loss, or parasitic drag vs. lift for the HIRO? Or perhaps any basic graphs or charts indicating the relationship between Cl and vehicle velocity?
When you did the track testing with the HIRO wing, did you initially drive the DA without the rear wing, recording the understeer and oversteer characteristics at varying speeds, and then drive the DA with the rear wing and record that data? Were there any noticable changes? (I.e., lateral acceleration of G-meter data vs. AOA)
From what I’ve seen at Leguna Seca Raceway, Virginia International Speedway, and Bonneville Speedway, the amature racing bodies within SCCA and NASA, i.e., ITA, HC, H1, and even Autocross solo 1, more often than not, competitors employ “GT” shaped wings.
I completely understand that wind tunnel testing is not a very cost effective way of gathering data for the HIRO wing. Although have you taken any dimensional data of the wing, and plugged it into any aerodynamic computer program? (I.e., something similar to Finite Element Analysis by Autodesk, but with fluid pressures, etc…) And if you have, what have you found?
Once again, thanks for answering the questions–I just hope you won’t get in trouble at work for spending company time a car club site.
-Andrew