SammyXp

I got tired of looking for a LMP (LeMans Prototype) or GTP style body for touring cars, so I decided to design one myself. I started another thread in the Paint/Body forum here:
http://rctech.net/forum/showthread.php?t=115485
But since I found someone to vacform the shell for me, I decided to start another thread here to discuss the design and hopefully get some suggestions on improving the aerodynamics.

Cliff notes are:

Here's the body (Audi R8):




I've got the opportunity to run the 3D model through some CFD (Computational Fluid Dynamics) software and had some interesting results. The validity of these simulations is in question, since the undertray in this model is smooth. I may try running one with the full chassis underneath it (I've got a TC3 modeled here), but the meshing itself will probably take 4 hours and I'm not sure my workstation can handle it.
For now, it's fun looking at the graphs:


Net drag is calculated to be:
0.62 lbf @30mph
1.72 lbf @50mph

Downforce is reported as:
0.52 lbf @30mph
1.45 lbf @50mph

Again, these numbers are approximated simulations, and not validated with testing as of yet.

The Lexan mold is currently being formed. Should be ready to pull the first few shells in a few weeks.

seaball

iTrader: (9)

i love you.

caveman

You are so cool

vtl1180ny

Can you say Gang bang???

That is excellent.... Kinda makes me wish I had of stuck to my ME degree and taked CAD more seriously....

I know there are a few Can am style bodies still floating around...

seaball

iTrader: (9)

i was just thinking one on one, really. unless this was a collaborative effort.

Anders Myrberg

Great work! I just don´t know if these numbers are good or bad.
The only thng that I like to comment is the position of the front body posts. Are you sure we can get the clips in between there?
This is where 1/12 should go, if you ask me.

SammyXp

Yeah, I really don't have any numbers to compare to. I had a lot of free time alst week when I modeled up the R8, but now I'm busy again. Else I'd be working on a model of a Stratus for comparison. I might have a guy here do a point cloud and just resolve some sheets from the data. Not totally accurate, but close enough to get some comparative numbers.
It took over 125 iterations for the solution to come even close to convergence, so I really do question how applicable these numbers would be in the real world. But one thing is certain - if I modeled up a Stratus, the comparison would be valid.

The front body posts bothered me, too. That's just where they end up, with the TC3 front bumper. Might be a problem with a few other TC's, possibly. The front shock tower is the biggest challenge with fitting the LMP to a TC. That's a steep rise, in comparison to the real R8. A Porsche Group C car might have made more sense. I just love the R8, though.

vtl1180ny, I'm a BSME, and it was five years of hell for sure, but I love my job now so it had to have been worth it. If you've got any Solid Modeling experience at all, model up a touring car and IGES the file to me so we can compare the drag/lift numbers! Shoot, if ANYONE has an IGES, STEP or parasolid of ANY car, let me know and we'll see how the LMP matches against a regular car.

CypressMidWest

iTrader: (1)

Oh my Lord, Anders and I actually agree on something!

Drew_Cat

iTrader: (1)

SammyXp keep up the good work.. You got a fan here

SammyXp

Thanks for the good words, guys. Really not necessary, but confirms my suspicions that there really is a demand for this thing. I guess I wasn't the only one that wanted peak performance, regardless of the rules.

speedxl

omg Where have you been all my life! dude you need to make that fit 12 scale asap!!! aswell as the Porsche. I'm also curious how it would turn out for tourer aswell. I am tired of taxi cabs!!

vtl1180ny

Sammy, I only know how to draw the old fashioned way. When I learned CAD it was on a 286 and it was horrible. There definitely is a market for LMP bodies. I'm tired of seing the same old shells over and over again... I never finished my degree, I was leaning towards aerospace and then I took a total change in professions... My wife is on me to go back and get my degree in ME.

XrayFK

iTrader: (1)

That looks great, I would love to run something other than a touring car body. Maybe you can look into some GT style bodies as well.

ford_racing

iTrader: (6)

What if you were to rotate the posts 90 degrees, so the holes are pointing forward, surely the clips would then be able to fit

SammyXp

Taxi cabs, haha. I love it. That's exactly how I see them. I thought they had an R8 for 12th scale, though? We'll see how this one goes and then I'll see where the demand is for other LMP or Group C cars.

XrayFK, what GT class are you thinking about?

vtl1180ny, if you're retired, you definitely ought to go back for your BSME. There is a major shortage of engineers. People just aren't interested in the sciences when there are so many easy ways to make money. I could so be making more money doing something else, but I probably wouldn't be having this much fun! Whenever I interview an RC guy for an engineering position, they get major points. Creativity and the willingness to embrace a challenge.

On the body posts, I was thinking of twisting them sideways so the clip would go in front to back.