Are the two current wing-planes too close to eachother? Is the gap big enough to feed the underside of the upper wingplane?

The longitud offset of the planes wrong?

With the pressure dropping so fast towards the back of the upper plane, there must be severe separation? It is starting to stall?

And/or the wrong angle of attack relative eachother?

Compare with this...

Another example would be to look at the wing of the old 993 GT2. Obviously, the two planes help eachother.

If these two examples (i.e speculations) are valid, the conclusion must be your upper wingplane must be placed further forward?

Looking at the radiator inlet. It seems to act like a big snow-plow pushing the air infront of it?

1) With a more rounded inlet shape, what happens?
2) With a faster increase of the duct-area from inlet to the radiator (i.e. smaller inlet area), should we not see a static pressure increase directly in front of the radiator?

The current inlet size is significantly larger than those on a F1... Is the current inlet area really necessary?

Lots of great suggestions, thank you

Let me start by pointing out a couple things about the picture:
- This is not the actual position of the wing in the car. This is one of over 100 simulations I ran, I just picked whatever I had open on my CFD machine to picture the pressure differential around the radiator.
- The pressure plot is clipped at a relatively low pressure, again to illustrate the pressure differential around the radiator, so it's not a great representation of the overall aerodynamics of the car.
- The wing was now moved to the rearmost position allowed by the regulations and a little bit upward to try and minimize the suction on the fastback. That didn't completely fix the problem, which also bothers me, but this is the centerline of the car, and that interaction only occurs in the middle 40 or 50cm of the wing, which has a 1.9m span, so while it's definitely not ideal, it's also not as bad as it looks.
- The model in the picture does have a diffuser, you can see the (fairly small) low pressure zone at the throat, it's just very thin. I don't remember if this was the latest version of the diffuser though but even that needs more work. And obviously the flow also changed when I changed wing placement.

Just for reference, here's a picture of the same run, just clipping at a slightly higher pressure, and you can see the difference. The low pressure zones above the windshield is orders of magnitude smaller than the low pressure zone under the wing:


The triple element image you posted is plotting total pressure, while I'm plotting static pressure, so the two images will never look the same. It's also unclear if the wing is in freestream, which changes a lot of things. Here's a total pressure plot for reference:


One thing worth noting is that the fastback was designed and printed before I decided to go down this rabbit hole, so if I had to do it again I'd definitely change a couple things. For one, when I tested with more aggressive triple element wings the effect of the fastback spoiler on the wing was positive, keeping the flow attached, but it wasn't wide enough, so flow separation still occurred about 30cm out from the centerline of the car, then it was attached again on the portion of the wing that was in freestream. So not only it could be lower, the spoiler also needs to be wider.

As for the front opening, it's rough to compare F1 with a production car... everything is so different. But in this particular scenario, F1 has several small inlets for all the heat exchangers, engine intake, etc. while I'm working with a single inlet for the radiator + intercooler which are over 4" thick when stacked together. The curved inlet is an interesting idea, and might be more efficient, but you are also creating a surface with an angle in the opposite direction of what you'd like, so it could create more lift than it'd reduce drag. I tried something similar with the side inlets and it backfired, so I rolled back to the flat design.

All in all, it's been a balancing act between building something that is 1) efficient, 2) looks good and 3) I can actually build in <6 months with my complete lack of experience. I have started learning 3d modeling and CFD just before I started this project a little over 4 months ago, and I have never even touched carbon fiber yet, so I'm trying to manage my expectations. I'm looking at this as a learning experience and if all goes well I'll resume the development soon.

Oh wow, it's been a month already... I've been meaning to update for a while now. The test/media day is getting closer and there's a lot that needs to be done before the car is presentable, let alone ready for the actual competition, but there's been a fair amount of progress too.

There's been some big changes/news, the biggest one is the new title sponsor for 2024: Link ECU. This was just surreal, I wrote a bit more about it on instagram, but the tl;dr was that I had to make the tough decision of selling my other ECU, and then this happened... I feel incredibly lucky and grateful, really can't put into words.



Besides that it's a lot of smaller progress updates:
- The fastback is out of the car, only missing now the internal reinforcements.
- The cooling system is done
- The plumbing between the intercooler and throttle body, including the Nuke blow-off valve is done. The turbo manifold should be here very soon and then I can finish the other side as well.
- The wiring diagram is finalized and the mock harness is done. Everything is ready to start the wiring, just prioritizing the bodywork for now
- All the fuel components are in place, just need to make the hoses now
- All the wing components are ready for assembly
- 99% of the carbon work is still left, but most things are prepped for the carbon, the only missing parts are the hood and quarter panels. The first quarter panel just finished printing, I'll assemble it this week, and I just finished modifying the hood so it no longer hits the engine, but it will require a little bodywork before it's ready for the carbon.
- The tires are here, just mounted the 2 wheels I have. The other 2 wheels are stuck in transit, but hopefully should be here soon.
- The steering wheel prototype is printed, just needs the hardware and soldering the wires



I'm sure I'm missing something, but I think that's the gist of it. It's been super intense to try and get the car done in such a short time, but it's also been a ton of fun and I already met a bunch of amazing people, so I wouldn't take any of it back. I hope that once the initial thrash is over and the car has turned some laps I can have more regular and detailed posts here.

Oh, somewhere in there I also printed this little miniature of the car, maybe someone here saw it at Speeding's booth at the Custom Motor Show.

Good progress