Internal Body Aerodynamics

[rtj]

Wow, looking at the cost of carbon fiber splitters, side skirts, and wings, this seems to be a skill to develop.

3d printing saved this guy a lot of time.

 

[phantomjock]

Guess I should get the 48x32x18 CNC I build out of the attic. Too bad I pulled all the electronics and servo/steppers. It would be a project unto itself! Not what I need, I am updating a new tow vehicle.
If you go this route - use a ShopVac (he has one) with a check valve - no hand pump required.

His results look nice - It would be interesting to compare "shop-time" to market price. And if he were to become a fabricator - just make the mold sections, and cnc mounts. Let the purchaser do the messy work. There are a few out there that would go that route - especially when/if they could specify/request a foil section and span. SuperBuickGuy?

Cheers - Jim

 

[rtj]

Wings would be the most difficult, side skirts and splitters are a lot less complicated.

Second hand apr gtc 200 and 300 wings go used for about 50% of new (or even less).

 

[BBShark]

How much does a wing (like the DIY guy made) cost? He probably has a ton a money in the materials to make the DIY version.

 

[rtj]

How much does a wing (like the DIY guy made) cost? He probably has a ton a money in the materials to make the DIY version.

I think 3d printers start around $400. But, like every thing, you keep upgrading software and computers.

There was a used APR GTC-300 for sale a few weeks ago locally for $800. So, unless you want something special it probably isn’t a good idea. There has been a second one for $1200 for months.

Side skirts in CF for a C8 are pretty pricey, so something like that would probably be worth the effort. Plus, tolerances aren’t an issue.

I’d really like to get into the CF skinning, so bear with me for posting all these.

 

[BBShark]

I think 3d printers start around $400. But, like every thing, you keep upgrading software and computers.

There was a used APR GTC-300 for sale a few weeks ago locally for $800. So, unless you want something special it probably isn’t a good idea. There has been a second one for $1200 for months.

Side skirts in CF for a C8 are pretty pricey, so something like that would probably be worth the effort. Plus, tolerances aren’t an issue.

I’d really like to get into the CF skinning, so bear with me for posting all these.

I think the cost of materials (CF, Epoxy, etc.) is pretty expensive right?

 

[rtj]

I think the cost of materials (CF, Epoxy, etc.) is pretty expensive right?

Mfain would be the best person to answer that question.

 

[mfain]

Yeah, stuff has gone off the charts. I use a lot of high-strength vinyl-ester resin. It now runs $150 per gallon. Epoxy is a little higher ($180/gal + $60/qt hardener). On a lot of pieces I build, I put a thin layer of fiberglass mat on the outside of the CF piece if I intend to paint it - less bleed thru in the paint, BUT epoxy does not work with fiberglass mat because of the binders in the mat. Vinyl-ester works fine, but I haven't been able to get any from my local supplier for over 2 months. I just bought a quart of Evercoat Vettebond panel adhesive. It used to be $72.00 - now it is $122.95. I used to use it like it was water to finish out molds - not so much any more. A quart of DP Epoxy primer with hardener is over $200. Go to this site: [email protected] You can find all of the current prices for materials and tools. BTW, there is a link to several good construction videos including one on fiberglass skinning.

Also, I am number one on the order list at a local dealer for a new Z06, but I was bypassed on the last order cycle because I am holding out for the Z07 and exposed carbon fiber big aero options. Guess what - both are on full constraint and GM has not indicated when the carbon bits will be available. I can't tell if it is supplier or material supply issue - maybe both.

 

[rtj]

 

[phantomjock]

[quote} Epoxy is a little higher ($180/gal + $60/qt hardener).[/quote]

Pappy - Try US Composites http://www.uscomposites.com/epoxy.html Based here in Florida.
Their Vinyl Ester is listed at $75.50 a gallon. Can't say what shipping would do though.
In my last order, a gallon of (medium) epoxy resin including 3:1 hardener was less than a hundred bucks.
You can't say that Fiberglast is held hostage by the "left coast," as I think they are Midwest based.

I started using some TotalBoat products as left overs from the boat. Nice 2 part high build primer that sprays well too. Very similar (I think) to your DP.

When the weather improves for laminating, I'll be back on it.
I have made some bits that would "qualify" as Internal-Body-Aerodynamics parts.
I'll have to clean the garage before I take some pics.

Cheers - Jim

 

[rtj]

It has to be very high end cfd flow vis, real smoke would never last like this.

 

[rtj]

 

[phantomjock]

It has to be very high end cfd flow vis, real smoke would never last like this.

There is a lot of interesting "stuff" happening in the Ferrari 396 video. Interestingly you can get smoke to streamline - but it gets all "messed up downstream - your guess may be correct - CFD adapted to a very high end graphic.

Anyway here are my observations:



The Yellow Streamline movement shows there is a lot of interesting things happening either under the bonnet (hood) or on top. At first glance looks like some louver action - but those are surface "stripes." [See the Orange Ellipse] I''d bet they are used for exactly what we see in the yellow stripe. Either surface heating differential or other clever means - or what the heck - just 'pretty stripes?' I remain suspicious. The Blue Highlighted Smoke flowing over the "Yellow Submarine" shows also very interesting entrained of the flow. Something could be happening with the engine cooling under the nose. Fan directing, radiator ducting. Note the slats located inside the exit. Clever. Are they Active Aero? Are there steering vanes underneath? Super-Buick-Guy - we've talked about this some I recall.

The shape and flow along the side in the areas highlighted in turquoise would be really nice to see. I'm naturally interested as you'll see in my sig, where I've been headed - and I think they copied me! (LOL).



All reasonable and clearly a good advantage - look at the flow over the roof and to the rear wing.
As a side note - I'd like to see what is going on with the front fender exit, the mirror stalk, the "ramp" and the rear fender entrance. There has been some efforts to use mirror stalks as a flow directing device.



For the front fender exits - the video gives a better look at the shaping of the side panel and the fender. Some clever ducting there to focus what we see down the side of the vehicle. The "Tailored Notch" looks a bit diffuser-like, wouldn't you say? I'll bet there is some significant area-rule work they've done just in that section.



The front view shows the wide overhang for the mirrors. Not only the stalk could be used to influence the flow, but the size and shape of the mirror. I have previously posted some work that had been done on mirrors to reduce their drag. This location is clearly intentional, and I bet plays a part in the overall flow.

At the rear - Deck. A subjkect of interest to all Notch -Back C-3s. The rear louvers are quite large in comparison to the early C-3s. Take a lesson Super-Buick-Guy! Here is a modern competition- level/street-wise car that has worked the issues associated with flying buttress, rear deck flow and wing.

What I'd like to see; the same smoke streamlines at 20 degrees off center. Now we see some real secrets!

That's all I've got for now. Man you gotta let me catch up!

Cheers - Jim

 

[rtj]

I heard one thing in this video that was new. That tire squirt vortices could upset the diffuser flow and strakes in the diffuser might help.

 

[rtj]

 

[phantomjock]

What this team has used is "Intuitive Aero Development."
When you "go with the flow" there is a lot you can see and improve.
Each of these improvements are readily applied to the C-3s.
This is a good video introduction to anyone that thinks it is all "Black Magic" and requires a huge investment.
Good find. A Great one!

Thanks for sharing it.

Cheers - Jim

 

[phantomjock]

Just caught up - the Body Roll/Aero has some similarly good info.
It lays out many of the transitions that occur in a corner and the impact on body/internal aero and handling.

I was reminded of the quick quote:
If it can't roll it won't turn.
It can only skate sideways,
Until tires reach the limit...

Cheers - Jim

 

[rtj]

Recent GM promo video. “Body in white,” I wonder if they will sell them like that. Just curious, I could not afford one.

 

[rtj]

This one actually has internal aero.

 

[BBShark]

Animagraffs has a lot of "how stuff works" 3D videos. How a F1 car works to how a P51 Mustang works.

Another Youtube channel that is similar is Real Engineering.

 

[rtj]

Yeah, I think I’ve seen the F1 vid.


Amazing how they keep upping the 911.

 

[rtj]

 

[rtj]

 

[rtj]

I picked up a GTC-200 a while ago. It was a bit scuffed up, but priced pretty low. And, it was structurally sound.

This one popped up a month ago, he dropped his price last week so I picked it up today.



Not sure if I’ll install either of them, but will have that option. The swan neck might even look okay on a c8.

Yeah, I know this started as the internal aero thread, but has kind wandered since then.

 

[rtj]

C8 with apr carbon aero.

 

[rtj]

I liked the look of the GTC 300 on the C8, so when this popped up cheap I grabbed it.



From what I picked up, he got it pretty oxidized and then clear coated it. He thendecided to sell it as he had others. I keep looking it over and can’t find any issues. I’ve leaned if some stuff pops up cheap, you grab it for future projects.

 

[rtj]

 

[rtj]

This c8 looks good with a straight wing.

 

[BBShark]

25HP over factory headers? I'm a bit surprised that GM went to all the trouble of designing a new engine for a new Corvette and saved a couple of bucks on the headers.

 

[rtj]

25HP over factory headers? I'm a bit surprised that GM went to all the trouble of designing a new engine for a new Corvette and saved a couple of bucks on the headers.

Pretty normal result I think. I was thinking the stock ones were pretty good.


The improvement was bigger in the old days.