Questions on splitter side plates / end plates / end fence design and theory
 

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Working on my splitter side plates / end plates / end fence or whatever name they are today?

Normal aero theory would just have a rectangle with a 4" height on top, although extending down or fwd would have more benefit yet get ripped off immediately.

Had a question on the pictured splitter side plate. I am thinking the jagged cut tall in front decreasing in steps to the rear is to encourage multiple smaller vortexes to evacuate the wheel well? Lost my race car aero book and CFD isn't my skillset.

Any input or photos on design and theory?

Something delicate that a aero engineer spent many hours developing only for it to be knocked off during a race and the driver never noticed and ended up going faster. In reality, it probably something unique to that design. As with most intriguing designs, its likely only work with a certain aero package. It also could be something rules driven and is a compromise to get the most of what square in is allowed.

+1 ^^

Need to know the context and back story, with an intimate understanding of the ruleset. Almost nothing in tightly regulated production car racing is an "ideal" design worth copying 100%.

You can understand "best practices" and generally good design, but exact size/dimensions need to be taken with heavy salt.

Air hitting center of nose is redirected in all directions. The air mass deflected to the sides is travelling laterally and lose pressure as it accelerate around the bumper and towards the wheel. In a straight line, it's all just drag as few production cars need more front downforce then.
When turning, the inside winglets do nothing, just add drag. The outside winglets (right winglets when turning left) are good L/D ratio, but only then. Trapping any air mass flowing across right edge of splitter when turning left, before it spills off the end raises its pressure, thus provide downforce.
This is the basis of AMB aero's infinity wing and most F1 front wings.

The image you linked is a pretty draggy front end overall. When drag is of no concern with massive power to weight ratios, time attack cars will often have huge fences on the ends of the splitters to trap air there. We have experimented with this a lot over the years. The difference in drag (Delta-V at end of straight) by making even small changes to splitter end plates is huge. WEC cars use canards more for vortice creation and overall airflow management than pure downforce. If you're above say, 8lbs/hp, I'd leave canards and bug end plates as a last resort. Lots of splitter area first. Then add low, removeable end plates that extend the entire side of the splitter. Only 1-3" high will slow the air mass enough to create useful downforce.

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Had extra material, some time and a bit more imagination than education.

BLKBRD any more info on how you sealed your lip to your splitter?

Not really sealed. Just a piece of foam filling the gap. Hasn't blown out at 150.

Is there a general rule to follow in terms of the vertical profile slope? Linear x/y decrease to a min y of 1" for example?

Emilio's post is enough guidance for me, otherwise follow the people who spend money on aero design, starting with the top tier TA cars. Or do some experiments on yours, see what works for you.

Of course, but nothing wrong with starting from a formula/rule of thumb if there is one instead of the "shot in the dark" approach.

Here's a good video of anyone wants to get started down this rabbit hole...