That image would be dope on a t-shirt.

Yo, every now and then I remember your videos during the day while thinking about my car. I love the logic and research behind it! Keep 'em up, great content

Maybe I missed it but the actual location of the various vents you mention is crucial and that is dictated by where the low pressure areas are. There is plenty of info around as to how to find the location of such low pressure areas. Of course the vent design is relevant to flow as well.

Finally, a chad who knows about the JACCS accord

Interesting. Very surprising results without ducted flow to the vent. I imagined a vent in the low pressure zone near the leading edge of the hood would be a hungry little vacuum cleaner pulling huge volumes of air out. The WRC engineers have been ducting to their vents for decades. Now we see why.

Thank you for including side ducting! I've been searching everywhere for research on them. On the topic of super touring cars, would you be able to do a video on the super touring wing profile, with its short chord length and massive gurney? Dimensioned cross sectional drawings of all the wings used can be found in the FIA database of ST cars. I would love to see the cfd results of that wing style on sedan/hatchback!!

As always I love your videos and the way you iterate adding more and more to the same model each time. It's a really wonderful way for someone like myself to learn a little bit more abouty aerdynamics as it pertains to vehicles and racing.

I had a friend who back in the 90's drilled 6 2" holes across the back of the bonnet of their Falcon ute and he claimed it made it a bunch faster. As we were traveling back and forth about 280km at the start and end of the week for work I asked how much difference there was to the speed/time over that difference. His answer was none. I actually wondered if a non destructive option would have been simply to put some spacers in the bonnet mounts and raise the back edge 1/2".

Love the aerodynamics breakdown, great work!

Love your content mate! front downforce is what I'm been trying to case in my GR Yaris.

Oh my god, dude. Literally the Video I need, right when I habe my morning coffee. I‘m restoring a 968 atm, and the race version had a vented hood, and also the engine bay gets hot as hell. Thanks for that one!

That’s very interesting how the front impacts the back. On my Mk1, I have the vent just on the edge of the low pressure zone on the hood and I have it raised with a gurney in front. This significantly increases extraction, and actually lowered drag a bit. I want to try like Audi did in DTM and venting a lot of the coolers into the low pressure areas in the wheel wells. What are your thoughts on aero balance for these FWD cars? I’ve been targeting about 60/40 downforce for the 65/35 weight distribution. The hope being that it understeers at high speed. The rear aero is also much less pitch/ride height sensitive.

Very cool how you took the time to break it all down with demonstrated models. Thanks for a cool vid

Great vid, I'll have to rewatch it a few times to understand it properly.

Always wondered how those corner vents worked!

Once again thank you very much for your videos.

all i learned from this was aero is incredibly complex on cars and applying them with regard to proper vent placement would be so difficult

What about pushing and tilting the radiator forward so you can try and get the bonnet vents into the low pressure

A while back I read an article about this topic that pointed out that it was easy to put a hood vent in a position where air would actually be forced into the vent instead of coming out of it

The model reminds of the Pinderwagen Greatly shown and explained. Interesting results

Educational. Thank you.

Bonnet vents can reduce the amount of pressure "pushing the front splitter down" as now the air can more easily escape which reduces downforce.

Lovw the video and the info. Have you thought about how hood venting affects something like the Stanceworks Ferrari? Huge bonnet vent for the rad but the engine is in the rear. Id love to see the airflow of a car like that

thanks, this information matters

The side vents was very smart, also tilting the hood like on some fwd won't work with the pressure there, now I see why they call it rice.

I note this is Open FOAM but what post processor did you use I like the way you made the car transparent to see the flow lines

usually the central vent is closer to the radiator and not in the middle of the bonnet, will it inpact anything?

Hello, great video! I was wondering if you are able to CFD with the hood raised up at the back like a Cowl hood. I've installed hood risers on my 92 Honda Civic and found that crusing highway speeds (80km/h and over) my engine revs drops 500rpm from ~4500 to ~4000 rpm with just the hood risers. But the previous owner removed the undertray and AC block off panel (beside the radiator). With all this information, I've concluded that without those panels I'm getting a lot of drag and lift in the front and under the car. With the hood risers, I'm assuming it's going up and over the body completely and the corner edge of the hood is creating a vortex to cancel out drag from my mirrors. I also have Spoon "style" duck bill wing I would like to add but I'm unsure how it's going to react with the hood raised. I can take pictures, if you're interested. Thanks for the awesome video!!

The late 90s Trans-Am has a tilted radiator. It takes hella space being tilted like that, space that some turbo piping would like to be in. Want to do a CFD on the tilted radiator vs upright?

How about a Naca type duct in reverse on the belly pan? That should create a vacuum in the engine bay by using the laminar flow from under the car

Is cowl induction a good system? I've never seen a touring car with this system, only a few drag cars. When you show "average pressure", do higher numbers mean greater efficiency? or am I mistaken?

Might be good to use side vents back over the tire where the air has a time to normalize and the flow toward the rear of the car. Closer to the car door.

What air speed are the simulations done at? I imagine a bonnet vent would have a more significant benefit at lower speeds and when stopped in traffic, so may be more useful on a road vehicle?

just did this in NFS U2 searching the same thing with the formula style vents

what about the rear of the front wing, like an r34 gtr z tune, or out of the wheels?

Im interested alot by how race cars pull heat out of the radiators. Nascar's next gen system is pretty cool and im sure other categories use it. Basically tho man I'd love to design my own intercooler configuration that surpasses the yobo standard I see with coyote falcons where they just plonk a heat exchanger in front of the radiator and condenser with no real ducting. Also those side exit vents must be why the EB2 v8supercar had its front end forcefully changed for EF spec. Better cooling and downforce which were more attributed to the vents than the dives planes by the looks of this ha

its a model on a computer... but wow that last one is cooling and functional 😌

I'm curious what the result would be of adding a gurney flap to the leading edge of vents.

What if we had corner outlets behind the front tyres ? Im not sure if it could work but ....

Do the corner vents on the bumper rob some of the high pressure at the leading edge of the tires?

Great video!! What is the CFD software you use ?

Missing a bit of detail here. Are the sidevents only "open" to the engine bay or are they also open to the underfloor and wheel-well? Meaning if they only pull air from the engine bay or also extract from the underfloor. Could you go into it's setup in a bit more detail? Perhaps in a bit more detailed video about BTCC aero and sidevents?

I couldn't quite understand the ending, I didn't understand exactly what "sealing the radiator" meant. Is it proposed to build a duct for the side outlet? Or just the side vent is already okay?

Did you rerun the baseline after extending the front undertray, as it seems in the video you haven't? 6:20

Any chance you can get a model of the Aptera? I would love to see the results!

What components does your Pc have ?

the engine bay vented? thats kinda sus

Move the engine further back and duct the radiator inlet and outlet 🤓

you talk like chef john from food wishes

Interesting how you slowed the audio own just enough to pass the magic 10minute youtube monetising mark

What about venting it under the car?

Why is there nothing under the car model? A lot of air will go in and under not over.

Apreciate effort you put in your videos, but many of them, forgets to include 1 or more crucial Part or design on a car, and you go chasing your tail about a problem, which will not be there in a real car. hence why you cant wrap your mind around it, in a real car that chaos of air flowing into the engine bay does not happen. if it did, even going straight cars at over 80km will be so dificult to handle, consumption will be out the door, add so much extra noise, that does not happen and all stock cars will have vents on the bonnet sides etc. your flow theory and diagrams could be true if there was no radiator fitted witout any plastic and rubber shrouding around it to completly seal air going into the enginebay. and your diagrams show that, the flow is only going thru your grills and straight thru the gaos and bumper. what youve completly missed is car radiators dont let air to flow thru like that. believe it or not, by the time its out the other side, it has lost 90% or more of its flow. most cars these days, have an aircon condenser, after that intercooler, after that the radiator. im not even talkig performance cars. have you seen the thins on these radiator/exchangers? never thought why so tigh, and even in the gaps they are very finely staggerd thins, if you shine a light thru it, you can't see the other side, literally to restrict straight thru air, 3 sandwiches of tightly packed thins. air just doesnt flow thru like how you've shown, and so much effort goes into the shroud design, so nothing gets in under, top and aroud the radiators aswell, what it does is, the air that needs to go thru, does, and its flow speed almost non existent by the time its gone thru, no chaotic deaf spirals left. and infront of the radiator you get a pocket of fair, infront of the radiator, which literally deflects any air hitting it over and to the sides of the car. if you have a look at grill designs even a big looking audi grills, only has a gap on the top section and a slightly bigger gap at the bottom going to the radiator, the rest isnt open, that much air just isnt needed for the radiators. it cant flow.and ive personally done these test, when the cars moving enginebay temps ar around 35 to 40c, at 80 plus km, outside air 20c measured at air filter box location in the engine bay. mostly due to the hot air getting sucked out from the bottom. as soon as you stop gets upto 65 - 70. when you turn it off heat soaks and can climb upto 95c the newest 2010ish onwards specially Eros cars run normally at 110c, even tough it will show you on your gauge at 90 right in the middle. can be checked with the simplest of diag tools. they now need to run hotter, all for emissions and better thermo dynamics. and they need to get the CATs to get hotter and faster I know this sounds like the opposite of what it we think should be. but thats the truth

False information about internal combustion engines here : 0:12 you say that ices are 35% efficient. That is not true. Toyota dynamic force engines are 40% efficient and 41% in hybrid state.

interresting......... but, that voice............

As someone who's been studying CFD at the highest level for the past 23 years, I can assure you you have absolutely no idea what you're talking about. This is just pure nonsense from start to finish.

I'm curious what the result would be of adding a gurney flap to the leading edge of vents.