Nocones $2020 challenge build thread

So, I dig it.

I'm a little torn about whether going to a central fin/wing mount and end supports tied to the diffuser would work/look... but I can see how fabrication of the current side supports will be easier... and probably make getting in to the engine easier.

i think the rear would benefit, both aerodynamically and visually, from the edition of a 'deck spoiler' along the back, just behind the 360's venting... maybe tying in to the rear wing support?

but, that's all imho... ymmv, caveats abound, etc. 

I tried your suggestions.  It does look a little more "LMP".  I like it.

I was also talking to a friend about the car and he suggested that I modify my plan to use 25" OD tires.  The original rendering is 22".  That was a big change.  The fenders had to come up almost 3.5".  It works and now that I see it finished it looks better and will have better future wheel availability.  Also I will be able to run SCCA Spec Coupe Subaru Rim sizes (17x8 w/ 245/40R17) which will be nice again for the future.  

Here is the comparison new to old.

This. Is. Awesome.

Thanks everyone.  I promise eventually I will move from digital to physical.  Its been a while since I used SketchUp, I forgot how powerful it can be.  I made a video of a walk around of the car.  I also added random License free music to give that a go.  

As I look at it, I’m not seeing where the suspension will go??

just pesky details to work out later I guess. Haha

Holy crap!  How have I missed this??

I’ve known this car was hanging from your ceiling since I sold it to you- I am super excited to see progress!!

You have a PM

In reply to jfryjfry :

Do you mean like suspension travel?  The model has about 1" of bump available and generally I render stuff 1" Bellow actual.  For some reason a car with 3" of ground clearance looks like a monster truck so I will render it closer to 2".  The MG was the same way.  

As for suspension arms and shocks there is space under the body for them.  I was going to run pullrods on this build which makes the suspension really short vertically.  For the rear I may run a DeDion  rear so I don't have  a lower arm which saves space also.

Even a DeDion needs lateral location. so a lower arm on one side at least, unless you want the roll center to be above the transaxle..I am a big fan of DeDion, and want to see you pull (rod) it off. I would contemplate a triangular lower arm ala Alfetta to accomplish low roll center, possibly with the chassis point behind the transaxle. Or, perhaps, a fixed length half shaft on one side, if the Subaru trans can handle it.

It's not real clear to me... but, is that a 2 or 3 surface wing?  What's the overall chord (leading edge to trailing edge, following the angle of attack {I.e. not the dimensions taken from directly above}), and the wing span?

I realize you kinda just slammed the fin/uprights in there... but, if you give me the wing dimensions, we can probably ballpark the force numbers, which will lead to some follow-on discussion of structures.

In reply to sleepyhead the buffalo :

Hey Robbie - do you have a spreadsheet for that?

why, yes, yes I do:

If you want me to plug in your chord and width numbers let me know. 

Also, I have this one:

NoCones:  

A bit of encouragement for you here. 

https://youtu.be/-AC4Gl2gdCU

Based on the 991 GT3

I think you'll want to add rows to 150mph, imho.  Might be ambitious... but maybe possible.
 

There's a couple concerns with the endplates/fin... one of which is that we'll want to WAG a number in for their side force due to Beta.  Primarily, the fin and endplates will need to resist the column bending vertical load from over 1000#s of downforce, but also single clamped beam bending from the side-load due cross-path wind.

This side-load is (seemingly) frequently overlooked; and it's possible that the structure to support the required column strength is enough to also handle this... but better to put a ballpark on it, than just assume it's okay and then have the thing fall off at 120mph.

Is the Subaru out of the rafters yet?

Stocked up on cutting wheels for the grinder?

Looking forward to some "Car" nage.

Pete

Would center driving position be possible? Seems like there isn't much room anyway for passenger, but if it makes shifter linkage a beast I could see that being a possible issue.

In reply to captainawesome :

It would be possible but I would like to avoid it.  If I keep the driver hips to left or right it is a 2 seater and has different classing.  

I am actually holding out some hope that I could offset the passenger seat slightly and potentially keep it an actual 2 seater.  Kinda like a smart car.  The car somewhat comfortably held 2 1960s humans.

In reply to captainawesome :

You are reading my mind!

nocones said:

In reply to captainawesome :

It would be possible but I would like to avoid it.  If I keep the driver hips to left or right it is a 2 seater and has different classing.  

I am actually holding out some hope that I could offset the passenger seat slightly and potentially keep it an actual 2 seater.  Kinda like a smart car.  The car somewhat comfortably held 2 1960s humans.

I didn't even consider classing when suggesting that. Where does this fall in Mod?

I will definitely look for input in aero.  Everything is just kinda for looks right now.  It's more Aero themed then legit aero of any specific size.  

I could use some help on general underbody air control theory and wing size for a balanced performance with the front aero.  

Not sure when I will get into that.  I'm going to size the rear for as large of a diffuser as possible.  The front I was planning to do a large splitter with vented rear before a flat floor (possibly with skirts) starts at the front axle.  If I run skirts I would have the elevated Chanel to have it have an inlet.  For now I have it rendered that way because it looks nice.  If it makes more sense to just do a full width flat splitter I will do that.

Aero development will come over time as the Sparks start to fly.

For now I am trying to figure out roll bar sizing and sourcing a tube bender and chassis steel.

Here I am waiting for a part to cool, browsing GRM and I think. Wonder whats going on in the challenge forum. I rarely check in here for some reason.

Then this

Need a little help from the experienced drag racers.

I'm trying to ensure that I build a sufficient cage for NHRA legality.    NHRA cage for tube frame is a bit strange.

My conclusion is:

tube size is 1-5/8 *.118 min wal for DOM for basically all tubes

geometry is fairly standard

the "tube frame" requirement is a piece of Min 2"x2" box section on both sides of the driver that the cage ties to.  

There are standards for welding plates which I will use beneath any roll bar attachement.

Does this chassis look essentially legal (realize it's missing rear braces and a main hoop cross brace.  The floor perimeter is 2x2 .058 MS

Good Lord!!!! Amazing project!

Can you put a human in the seat with helmet for scale?

Can you also run a quick class on how to put amazing things like this in to SketchUp because jfc idc if it ever gets built, I just wanna keep looking at these drawings.

You sure you need a full cage? A roll bar is sufficient down into the 10's, and the diagonal side supports can really stiffen the car. 

I built Datsaniti's roll bar out of 1-3/4 x .120 ERW tube, because it was so damn cheap. And you can buy pre-bent main hoops from Amazon for ~$40 shipped... just search this P/N in Amazon.

https://www.summitracing.com/ga/parts/cee-3126/overview/