[RideMooch]

Just thought I'd poll the audience to see what kind of aero everyone is using. I saw Greg's Race Parts is working on a chassis mounted wing solution which looks awesome...but is not SSM legal as it hangs off the back of the car. It got me thinking though. Share your setups!

Mine is very simple, just an APR GTC200 wing, which came on the car when I bought it and likely does nothing at AX speeds.

 

[cyow5]

On Rails Engineering has my favorite wing mount idea so far with Phil's gooseneck in 2nd place. If you haven't read it though, there is a Reverie/RaceCar Engineering article that pops up from time to time outlining some neat wind tunnel results.

Remember, all wings produce downforce at zero speed, haha

 

[TachItUp]

No aero here, but that GRP wing looks awesome.

 

[glagola1]

I got my wing form Ciro. It can be ordered in SSM legal configuration. I had to fab my own mounts in the trunk to attach it to the chassis. And then I made my own splitter and flares.

 

[RideMooch]

I got my wing form Ciro. It can be ordered in SSM legal configuration. I had to fab my own mounts in the trunk to attach it to the chassis. And then I made my own splitter and flares.

Matt, do your wing mounts pass through the clam and mount in the trunk/chassis? or does it bolt to the clam with supports in the trunk to the chassis? any close ups?

 

[RideMooch]

On Rails Engineering has my favorite wing mount idea so far with Phil's gooseneck in 2nd place. If you haven't read it though, there is a Reverie/RaceCar Engineering article that pops up from time to time outlining some neat wind tunnel results.

Remember, all wings produce downforce at zero speed, haha

You mean this ORE wing? can't tell how it's mounted but looks like its just on the trunk lid which doesnt seem very secure or effective. Also doesn't look like they're marketing this, but it's a one off.

 

[glagola1]

 

[acslater]

+1 for Phil's swan neck design. I'm running Reverie aero all around with their tallest stanchions, but I plan to eventually go frame-mounted.

So far, no issues with the wing overpowering the mounts or putting any cracks in the clam even at 135 mph

By the way, one comment about wings, and specifically the APR GTC200 (which really is a great deal): if you mount it high enough that it's in clean air, the compound design diminishes the effectiveness since the wing will have different stall speeds along its length.

 

[lotus90]

I recommend front air splitter. it helps with down force and protects front clam. I run front air splitter and difflow diffuser. I find the car feels more planted.

 

[RideMooch]

I recommend front air splitter. it helps with down force and protects front clam. I run front air splitter and difflow diffuser. I find the car feels more planted.

I'd love to fab a splitter for my car, but then I can't get in my driveway :crying: and I still street drive it a lot. And unfortunately in SSM an aftermarket diffuser is verboten.

 

[cyow5]

You mean this ORE wing? can't tell how it's mounted but looks like its just on the trunk lid which doesnt seem very secure or effective. Also doesn't look like they're marketing this, but it's a one off.

Right, it is just a one-off but still my favorite I've seen. I spoke with the owner of that car and it seems well-done. Also, think about the static physics and you'll find that you do not need to mount directly to the chassis as long as whatever you mount to can support it.

I always prefer efficient results over brute force, so I lean towards low/rear mounted wings. Clean air is great for a constant cross section wing, but remember our cars have underbody aero. Mounting low and rear pulls more air through the diffuser. The wing works less effectively since it does not have clean air, but you can get the same downforce with less drag. Again, see this paper for some really neat (and often counter-intuitive) insights

http://www.abendanio.com/Manuals/Auto/lotus-service-manuals/Racecar Engineering- Lotus Exige Aerodynamics.pdf

His book also goes into a little more detail on the results. Another interesting point, the Exige is not a true fastback design since it has the wire mesh back there, so the aero isn't nearly as clean as, say, Phil's true fastback.

 

[acslater]

I'd love to fab a splitter for my car, but then I can't get in my driveway :crying: and I still street drive it a lot. And unfortunately in SSM an aftermarket diffuser is verboten.

As far as diffuser, you should be able to at least run an above-exit exhaust and close the exhaust hole, right? From what I understand, the oem exhaust tips coming through the diffuser have been shown to render it effectively useless. (You may have already done this, can't tell from your picture)

 

[RideMooch]

As far as diffuser, you should be able to at least run an above-exit exhaust and close the exhaust hole, right? From what I understand, the oem exhaust tips coming through the diffuser have been shown to render it effectively useless. (You may have already done this, can't tell from your picture)

Haven't done that yet, but it's high on the list (PPE header, catless test pipe, BOE QS); however, I seem to recall the way the rules are written you still cant close off the OEM hole in the diffuser. Maybe glagola knows the answer to that.

 

[acslater]

@cyow5, seems to me this paper makes an argument for a higher-mounted wing, up to a certain point. But higher was MORE efficient than lower-mounted wings. The caveat to that was that the exhaust was running THROUGH the diffuser and stalling it out, meaning that there wasn't interaction between the wing and diffuser. That's not the same as saying that a low-mounted wing with an effective diffuser is more efficient than a high-mounted wing with an effective diffuser.

 

[acslater]

FWIW, ReVerie generally says that as high and far back as possible (under given rules) is the rule of thumb for mounting a wing, and that compound wings are only effective if their twist has been designed specifically to suit the airflow over the vehicle it's being installed on.

 

[cyow5]

@cyow5, seems to me this paper makes an argument for a higher-mounted wing, up to a certain point. But higher was MORE efficient than lower-mounted wings. The caveat to that was that the exhaust was running THROUGH the diffuser and stalling it out, meaning that there wasn't interaction between the wing and diffuser. That's not the same as saying that a low-mounted wing with an effective diffuser is more efficient than a high-mounted wing with an effective diffuser.

Right, the diffuser in this case was heavily underutilized. Aero is all about package and not components, so you just have to try and see (or run a proper sim on a supercomputer). Catching something like ride height, wing type (OE exige style in their case), etc, and you can achieve weird results. I am building my entire package around the diffuser, so that's why it is important to me. Look at the downforce of the wingless 458 and you'll see the virtues of underbody aero. I am also adding vertical extensions to my side skirts (just got the UPS notification they arrived!), extensions to the diffuser strakes, and cut inlets in the front splitter (recall that splitters consequently reduce underbody airflow). I also am going to add oil cooler block-offs and a contoured underbody which is will work great with the vertical skirt extensions.

 

[acslater]

Right, the diffuser in this case was heavily underutilized. Aero is all about package and not components, so you just have to try and see (or run a proper sim on a supercomputer). Catching something like ride height, wing type (OE exige style in their case), etc, and you can achieve weird results. I am building my entire package around the diffuser, so that's why it is important to me. Look at the downforce of the wingless 458 and you'll see the virtues of underbody aero. I am also adding vertical extensions to my side skirts (just got the UPS notification they arrived!), extensions to the diffuser strakes, and cut inlets in the front splitter (recall that splitters consequently reduce underbody airflow). I also am going to add oil cooler block-offs and a contoured underbody which is will work great with the vertical skirt extensions.

Very cool, I get where you're coming from now. My next project is going to be to extend the fences on the diffuser too - crazy that it yielded such an awesome improvement in that piece, even with the center section stalled out!

 

[kfennell]

I'd love to fab a splitter for my car, but then I can't get in my driveway :crying: and I still street drive it a lot. And unfortunately in SSM an aftermarket diffuser is verboten.

Diffusers are banned in SSM? Did not know that, I guess XP for me then? I don't even have the OEM anymore.

 

[cyow5]

Very cool, I get where you're coming from now. My next project is going to be to extend the fences on the diffuser too - crazy that it yielded such an awesome improvement in that piece, even with the center section stalled out!

Yeah, I am looking at using something consumable like a heavy rubber or polycabonate since they'll scrape on everything. Another option I am looking at is hinging it at the front of the extension so it can deflect upwards. That's the trickest, but the others are easier.

 

[kfennell]

Diffusers are banned in SSM? Did not know that, I guess XP for me then? I don't even have the OEM anymore.

My reading shows a 25" diffuser with strakes a minimum of 6" apart is allowed, my diffuser meets these rules (difflow railer I think), can anyone show me I am wrong?
It does look like the GRP wing above would NOT be AX legal in any class?