Introducing Affinity Aerodynamics the source for Hardcore NSX Aerodynamic Performance

[Affinity Aero]

Affinity Aero modeled, molded, and produced.

 

[jones83]

Cody, is the front diffuser completely flat like in the one picture? I was under the assumption that you needed a dimple in diffuser to reduce the high pressure. I know that aero is ever evolving, but I believed this was a universal thought.

 

[stuntman]

^I think that ~1" 'void'/'dimple' was created by sanctioning bodies to disrupt the airflow under the car to limit downforce. That picture would cause the air to expand slightly (to create downforce) but then it angles back to the same plane and height as the splitter, eliminating any downforce created and possibly disrupting the flow behind it.

A front 'diffuser' would create more downforce by expanding the air in it and accelerating the air in the 'throat' (flat section in front of the diffuser) to create a fast moving, low pressure area = downforce.

 

[Affinity Aero]

The splitters as of now are meant to be a budget option for the track day enthusiast. A more comprehensive splitter, or "diffuser" as stuntman put it, is basically shaped like the underside of a wing, using the venturi effect to produce downforce. We can build such a thing, but without significant interest we won't bother with the tool up. It would be 3D in shape and would require molds and composite parts. Aka, "not cheap". We are designing our shop cars entire underbody based on this principal, so we are familiar with the concept.

 

[Affinity Aero]

We still have to build the throat(entrance)of the underbody, but the exit is fairly simple. It'll be converted to Carbon after initial chassis testing....

 

[stuntman]

What's the angle of the tunnel? The vertical wall makes a pretty sharp turn, I would be interested in (keep an eye on) to see if there is flow separation when the air tries to make such a sharp turn.

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[TURBO2GO]

Cool logo Cody

 

[Affinity Aero]

Fan testing shows full attachment on every surface stuntman.

 

[Affinity Aero]

Cool logo Cody

Thanks to my customer Jeff Melnychuk! He offered to assist, threw a few ideas my way, and that one stuck out.

 

[jaja]

Have you guys performed any testing with only one device installed at a time? i.e. If I wanted to only get the splitter, would I have any balance and in-tern stability issues at high speeds with so much front heavy aero?

 

[Affinity Aero]

Have you guys performed any testing with only one device installed at a time? i.e. If I wanted to only get the splitter, would I have any balance and in-tern stability issues at high speeds with so much front heavy aero?

The concepts have been tested over the years, yes. The effects are immediate and pronounced. Depending on what your car needs and/or what the driver prefers, you could dial the package accordingly. Aka, if your car pushes and you prefer more front grip, install the splitter. If the car is loose, look at the diffuser and/or wing combo. If it's balanced and you want more overall grip, look at the entire package(splitter, underbody, diffuser, rear wing). We are moving toward carbon fiber production on all of the parts, as the weight savings are worth the extra cost, however, this takes time.

We are in the dead of winter with snow falling daily, so we won't have dry roads until April by the looks of things. Regardless, we are pressing on based on knowledge gained over the past 8 years, and skills(carbon fiber) being honed as we speak.

 

[stuntman]

Fan testing shows full attachment on every surface stuntman.

As speed increases, the rearward boundary layer becomes thicker and separation creeps forward. If its fine with a 40mph fan, you may have issues at 60mph and likely at higher speeds. Might be something to keep an eye on.

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[shawn110975]

what a lot of owners are looking for is a complete underbody cover, with ribs.

from front of car to back but the engine area is cut open and the 4 wheels are cut

 

[Affinity Aero]

Thanks. It'll be monitored when we get the car rolling, though the rear wing(triple element) we are building for the car will pump it pretty well. We may have CFD results by then as well, which will help us with direction ahead of testing.

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what a lot of owners are looking for is a complete underbody cover, with ribs.

from front of car to back but the engine area is cut open and the 4 wheels are cut

This is on our list. The splitter will meet the underbody panel with a slight diffuse- shape, and the underbody panels will have vertical skirts to replace the heavy factory side skirts. It will be heavy(and cheap) or light(carbon fiber, and NOT cheap).

 

[Affinity Aero]

Nearly have the first wing completed. Once we figure out the mounting method, we will likely launch an introductory Group Buy.

 

[Affinity Aero]

End plates for the Affinity Aero TA Series wings fresh out of the bag, prior to trimming.

 

[Affinity Aero]

We've had an awesome request from our customer. Study these pictures, and stay tuned....

 

[jones83]

Looks like you will be making a DTM style wing for the nsx?

 

[Affinity Aero]

Chassis mounted, easily removable, lightweight, which will also double as a diffuser mount.

 

[Affinity Aero]

A great start on the attachment points last night. Integrated into an all-new, bolt-in lightweight rear bumper beam.

 

[Affinity Aero]

After completing the prototype TA Series Chassis Mount mounting system, we found that the NSX chassis itself is nowhere near rigid enough to support the kinds of loads this wing is capable of generating. The rear bumper beam mounting locations are sufficient for lateral and longitudinal stresses, but not torsional, which is unfortunately what this wing mount introduces with substantial loading.

So, we are starting over, working with a swan-neck mounting style, mounting to the trunk via cnc brackets and risers. This also means a new wing element, but we have a use planned for this one.

We'll update when those are out of machining.

 

[jones83]

^I think that ~1" 'void'/'dimple' was created by sanctioning bodies to disrupt the airflow under the car to limit downforce. That picture would cause the air to expand slightly (to create downforce) but then it angles back to the same plane and height as the splitter, eliminating any downforce created and possibly disrupting the flow behind it.

A front 'diffuser' would create more downforce by expanding the air in it and accelerating the air in the 'throat' (flat section in front of the diffuser) to create a fast moving, low pressure area = downforce.

From what I have gathered what you just said isn't accurate. The air initially comes in and should be angled like cody said similar to a wing, but then it is accelerated to the rear due to the dimple in the diffuser. Other diffusers use this such as Voltex, Varis, etc.

 

[stuntman]

From what I have gathered what you just said isn't accurate. The air initially comes in and should be angled like cody said similar to a wing, but then it is accelerated to the rear due to the dimple in the diffuser. Other diffusers use this such as Voltex, Varis, etc.

No diffsuer used in motorsports angles back down to the original plane, that defeats the inherent goal of expanding the air to accelerate the air in the 'throat' of the diffuser. What you posted is pretty much identical to what was used in the JGTC NSXs to limit the downforce of the car by the governing bodies:

 

[jones83]

That's not a JGTC diffuser and I wouldn't say no diffuser as you haven't seen every diffuser from everyone. The typical diffuser is flat and so are the typical under belly panels. The people who are trying to be faster than the rest add channels and different angles to expedite the air to the rear faster. This is an underbody that was used on one of the fastest time attack cars in the last few years.

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No diffsuer used in motorsports angles back down to the original plane, that defeats the inherent goal of expanding the air to accelerate the air in the 'throat' of the diffuser. What you posted is pretty much identical to what was used in the JGTC NSXs to limit the downforce of the car by the governing bodies:

View attachment 121683
View attachment 121685

or 2003, a ruling that has been enforced for a number of years in the Le Mans and FIA regulations makes it way into the JGTC. Between the centerlines of the front and rear wheels of the car, the underbody must be fitted with a flat bottom. As a result, the down force of the car is affected remarkably. "My first impression of the car during the shakedown was... 'My goodness. What's that feeling? There's a bit less down force, I wonder?'" commented Daisuke Ito after driving the No.16 NSX entered by Mugen. "If we set the rear wing-angle to that of last year, there is entirely too little grip. There has been a tremendous reduction in down force."

They weren't forced to have that dimple between the wheels like you are saying.

 

[stuntman]

^Those longitudinal "channels" are often referred to as "tunnels" which create vorticies and act like very large diffusers. You're original picture had a transverse section (like the JGTC which you referred to as a 'dimple', which does not add downforce to the car. Those 'tunnels' in the picture above, if properly designed can make a lot of downforce. Completely different from your original photo.