Building the FASTEST Formula 1 RC Car

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FIND - A - TUNNEL (with a flat ceiling)

If anyone is interested in fan cars, the McMurtry Spéirling recently broke track records, proving that ground effect is very effective under the right circumstances.

James you MUST do a part 2 and see if you can get it to drive upside down! 🏎

the long awaited sequel is here

Some suggestions: How about a skirt made from a brush? How about putting the ground effect tray on a separate set of suspensions from the main chassis? One irl example is the Lotus88 One I've been asking myself watching the video is what lead to the choice of a propeller instead of an impeller to evacuate the ground effect tray, as the latter is way better at producing a pressure difference?

There is a BBC documentary called "Gentlemen, Raise Your Skirts". About the ground effect cars Williams had back then. No fan but shaped underfloor and the skirts were spring loaded carbon strips that could retract up and down into a slot so they could touch the track surface and follow the imperfections in the track. Check it out if you can, it's awesome if you like those old BBC doc's.

The Chaparral did this long before the F1 car you cited. The concept is valid but was outlawed because the fan throws stuff all over the following cars.

The original Lotus car had sideboards mounted on slots so they would always adjust themselves to be touching the ground. Your front skirt-board doesn't need to create a perfect seal to the ground. If it's bouncing on the ground it will be slowing your car down. Some of the F1 cars used broom bristles to create a seal.

High pressure flexible 'tubular' perimeter skirt, low pressure chamber: Forget the walls, replace the skirting with something akin to a hovercraft skirt, but with the skirting pressurized to keep it inflated. I also suggest a tough material, as it will be in contact with the ground at high speeds.

The issue was you locked the suspension out. You effectively cancelled out the mechanical grip of the car. In turn, you also proved the effectiveness of the design. Double edged sword so to speak. You must have heard of the McMurty special right? If not....bro.... where have you been?

If my memory is correct the seal was made in more than 1 over lapping section so the road contact area could be worn away then slide down to replace it. Eg had a total loss section that lowers as it's warn away.

You found what brabham found - it is really hard to get a good seal on a road surface. Passive underfloor ground effect ended up quite quickly outpacing the active design. Fun tho! And you didn't have an actual human driver experiencing the rapid fluctuations in the effect; the drivers were terrified by it.

Fun fact. Gordon Murray (the designer of the BT46B fitted an aeroplanes altimeter in the cars so that it would show whether the underfloor was sealed. The drivers had a problem that the skirt would be damaged and they wouldn't know and suddenly find themselves going through a corner about 40mph quicker than they could without the ground effect and having a colossal crash. So if the altimeter was in the green they could push. If it wasn't they had to back off.

This is extremely sick, and you pulled it off so well! I have been thinking about doing something like this since seeing the Formula Student car from ETH Zürich use a similar approach for reaching 0-100km/h in under a second. IMO it's impressive how much extra downforce you ended up getting in a straight line on this. To improve the seal on bumpy roads, maybe you could try a 3d printed flexible TPU base with a sort of skirt around it from thin PTFE that is too long and just bends out when the car is further to the ground, but then extends once it goes more above it or over a bump?

I believe the Chaparral 2J had its skirt mounted to the suspension, not the chassis. This way the skirt stays flat with the wheels, and doesn't move with the body. Try mounting the skirt to the ends of the suspension near the ball joints, and I bet you'll have more consistent suction and longer lasting skirts.

The part you missed, or couldn’t replicate from the original fan car, was the skirts moved up and down inside a channel in the sidepods so that they maintained the perfect hight to the road all the time, the last time I saw one it was effectively a draft excluder bolted to a piece of plastic that sat in the channel. I’m also fairly sure they didn’t completely enclose the skirts at the front (and probably the back) of the car as that was how they drew the air in to create the vacuum. There’s no way this is practical to do on that size of car but maybe a bigger one?

its always good to see him upload and it makes my day

This is epic, ur an awesome creator, don’t stop being awesome!

Love to see this run on a basketball court where the floor was perfectly smooth. That would let it really corner. Seems like for the skirt, some thing pliable but durable like silicone sheet would be good. Great vid as usual!