What do we think of this rear wing?

My long term project is a rebuild of my '70 Firebird which includes a bunch of aerodynamic changes. My hope is that the changes I've been working on will increase front down force enough to require a rear wing to balance the car. In my dreams, I envisioned a swan neck dual element wing that met specs determined by a race car aerodynamisist with CFD programs, and much better math skills than I have hahaha. However, that's probably not in my extremely limited budget and this used wing sort of fell in my lap within my budget so even if it isn't optimal for my car it's a learning tool and I'm not trying to "win" anything with the car anyway so nothing to lose so to speak. I used the car before the rebuild for HPDE track days and will do the same once it's back together with a slim possibility of time trials at some point once I get the car sorted.

This is a carbon fiber single element airfoil made by Reverie in England. 10" chord, approximately 1 1/2" thickness, and 68" span. I'll need to fabricate brackets for it as the ones on it from a previous installation (Noble M400) won't work for my application. Here's a few pics so you can see the profile etc. Anyone see any real problem with trying this? Determining placement is my biggest question if it's a decent airfoil design.

[URL=http://s240.photobucket.com/user/NOTATA/media/Carbon%20fiber%20wing/20190912_165252_zpsuwl6dwro.jpg.html][/URL]

[URL=http://s240.photobucket.com/user/NOTATA/media/Carbon%20fiber%20wing/20190912_163910_zpsp4pkgpmi.jpg.html][/URL]

[URL=http://s240.photobucket.com/user/NOTATA/media/Carbon%20fiber%20wing/20190912_163215_zpsgn7nci99.jpg.html][/URL]

Wait, a Reverie-made wing fell into your lap? A straight profile single element Reverie costs almost $1000 US new. How on earth did that happen?

As far as the profile, that clearly looks like it was built for a low-drag application. The upper surface of the wing looks flatter than any of Reverie's current designs and flatter than most aftermarket wings I've seen. I can't imagine it would hurt to use it, but I also suspect that you might not feel it much unless you run a few degrees of AoA or are running at over 80 mph.

NOT A TA said:

My long term project is a rebuild of my '70 Firebird which includes a bunch of aerodynamic changes. My hope is that the changes I've been working on will increase front down force enough to require a rear wing to balance the car. 

This is a carbon fiber single element airfoil made by Reverie in England. 10" chord, approximately 1 1/2" thickness, and 68" span. Anyone see any real problem with trying this? Determining placement is my biggest question if it's a decent airfoil design.

 

The placement is going to depend on the front downforce. The further aft you can put it the better with the low camber (curvature) of this profile. You will need some angle to get it working but that can mostly be accomplished with your custom pylons. If you are trying to mount it high, then as far back as you dare. If you are mounting it low, then mount the leading edge just overhanging the trunk edge ~1".

This profile would be good in the future as the first of your two element assembly, so room to grow.

Question for Stafford1500 - why the overhang when mounting it low? I get that there's probably some ground effect interaction with the trunklid, but wouldn't the distance from the surface of the trunk be more critical? Or is the transition from a surface to a vaccuum that you're trying to take advantage of?

Cool wing, nice score! How much does it weigh?

Keith Tanner said:

Question for Stafford1500 - why the overhang when mounting it low? I get that there's probably some ground effect interaction with the trunklid, but wouldn't the distance from the surface of the trunk be more critical? Or is the transition from a surface to a vaccuum that you're trying to take advantage of?

You’re trying to make the wing into ‘effectively’ a second-element acting device to the car-body.  Because the car ‘first element’ is so big, your vertical distance from the trunk has a bit more wiggle room, than say a multi-element wing.

The reason to get it 1” over the trunk is to use the first part of the low pressure zone from the wing over the trunk to keep the flow over the rear window & trunk attached.  But you want the majority of the low pressure zone from the wing (in the 10 to ~40% of the wing, conveniently in the case the 1-4” chord range) out over the back of the car so that the low from wing helps draw more air out from the bottom of the car.

doing this helps both rear downforce, *and* front downforce assuming you have a front under-tray/splitter

ymmv, iirc, etc caveats

boxedfox said:

Wait, a Reverie-made wing fell into your lap? A straight profile single element Reverie costs almost $1000 US new. How on earth did that happen?

As far as the profile, that clearly looks like it was built for a low-drag application. The upper surface of the wing looks flatter than any of Reverie's current designs and flatter than most aftermarket wings I've seen. I can't imagine it would hurt to use it, but I also suspect that you might not feel it much unless you run a few degrees of AoA or are running at over 80 mph.

Sometimes it's really bad to be me, sometimes it's good! I will trade some of my labor for the wing, so no out of pocket expense.

Your observations were the same as mine. I believe the wing was a custom design for the Noble M400 and as such was more "decorative". Will see if I can dig up more info. No provision for a gurney flap that might be useful?

stafford1500 said:

The placement is going to depend on the front downforce. The further aft you can put it the better with the low camber (curvature) of this profile. You will need some angle to get it working but that can mostly be accomplished with your custom pylons. If you are trying to mount it high, then as far back as you dare. If you are mounting it low, then mount the leading edge just overhanging the trunk edge ~1".

This profile would be good in the future as the first of your two element assembly, so room to grow.

I've been telling myself I need to start a thread here on all the aerodynamic modifications now that we have an "Aero" section. I do plan on putting it way back and will need to figure out how high. That would be a great topic for posts as part of a thread on all the mods.

I hadn't even thought of this as the lower section of a two element, EXCELLENT ADVICE!

Robbie said:

Cool wing, nice score! How much does it weigh?

About 9-10 lbs including the stanchions.Will get an exact weight of airfoil alone with digital scale when I take it apart. For quickness I just weighed myself and then holding wing on cheap bathroom scale yesterday.

This is the car but will have a splitter/under tray/rear diffuser. A lot of it's already made.

[URL=http://s240.photobucket.com/user/NOTATA/media/Sebring%2009/Sebring10309020.jpg.html][/URL]

NOT A TA said:

Sometimes it's really bad to be me, sometimes it's good! I will trade some of my labor for the wing, so no out of pocket expense.

Your observations were the same as mine. I believe the wing was a custom design for the Noble M400 and as such was more "decorative". Will see if I can dig up more info. No provision for a gurney flap that might be useful?

That's awesome. The good news is that adding a gurney flap to a composite wing is really a matter of gluing one on with resin. A wing like that would definitely benefit from a good bit of wicker. Since we're talking a 10" chord and a relatively flat top profile, maybe something in the order of 3/8" - 1/2" tall?

Nice wing!  

James May's definition of a wing

NOT A TA said:

Robbie said:

Cool wing, nice score! How much does it weigh?

About 9-10 lbs including the stanchions.Will get an exact weight of airfoil alone with digital scale when I take it apart. For quickness I just weighed myself and then holding wing on cheap bathroom scale yesterday.

Thats how I weigh all my stuff nowadays, although I did get a digital baby scale for free recently.

10lbs is awesome.