Making a more efficient, aerodynamic soapbox gravity race car

[iamnotahippee]

Another thought....what about adapting bobsled design? They are a gravity vehicle, handling is important, and on team bobsleds the position occupants is mostly upright.

[orengomotors]

Originally Posted by euromodder

Tyres seem to be a very much outdated design offering less than optimal lateral grip and stability
There's just about nothing between the thread blocks to keep them stable and the pattern will make them follow ridges in the road .

I'd think you may be better off with something like this



Reifenwerk Heidenau


What size are they ?
8" by 4" wide (size I got from the googling mitas super B5) ?
If so, that seems to be limiting the choice a lot .


Dual compound scooter or motorcycle tyres could offer a lot of grip on their sides.
Front compound is softer as it doesn't have to lay down power, but the harder part of the rear tyre is narrower - so you'd need to take into account the camber to see if you'd really be running on the softest compound of the front tyres.



Cool video

That 3 wheeler was passing you in the hairpins where I'd think you could go faster
Three-wheeler seems to have bigger wheels, is that right ?

But your kart is faster
With a shell, it'll go faster still (aero + a bit extra weight) so it needs to turn better as well.



The driver is laying down - so it's very low.
That kind of design won't work with your upright seating position
You'd still stick out like a sore thumb

ChazinMT's design is more suited for what you've got, but enclose the rear wheels as well ; and make the headrest fairing narrower or round off the front some more.

I use the mitas super b5 tires, they are the wining tyre every year in the europeans championship.
another tire can be better, but i haven't tested a better tire yet.
i used a ruben slick, but those tires where so small and nervous.

it will be great to hear some tire advice, regulations say that has to be 450mm or less, and my rim is 8"

[orengomotors]

Originally Posted by iamnotahippee

Another thought....what about adapting bobsled design? They are a gravity vehicle, handling is important, and on team bobsleds the position occupants is mostly upright.

that's a good idea!

[orengomotors]

well, after my towns race the season is off.
in my town race i finished in the thirds place.

https://www.youtube.com/watch?v=40TJ2ofQDEE

Now i will center my efforts on improving the soapbox, and studying for school
i will be updating this post.

[iamnotahippee]

Very cool!

[orengomotors]

The soapbox is now 3cm lower, the ride height now is 9 cm.
Now I'm working on the front, to make some 30cm more of leg room to lean more and reduce frontal area.

[orengomotors]

Also, i'm very interested in the regenerative braking system, how can it be done?
thank you

[freebeard]

I'm not sure why you need KERS (Kinetic Energy Recovery System on a gravity racer, but your choices generally would be electric, hydraulic, flywheel or a great big coil spring.

What is allowed by the rules?

[orengomotors]

Originally Posted by freebeard

I'm not sure why you need KERS (Kinetic Energy Recovery System on a gravity racer, but your choices generally would be electric, hydraulic, flywheel or a great big coil spring.

What is allowed by the rules?

well, the races are not in straight line, and in some curves i will brake, if this energy can be recovered and used in a flatter zone i will be perfect!

the rules limit the battery capacity.

[botsapper]

10 years ago, I was able to see the Xtreme Gravity Racing Series (a charitable event) that had huge corporate support and allowed the use the world's top car designers and automotive engineers (Art Center, Pininfarina, Volvo, Bentley,Audi, VW, Nissan, Chrysler. Mazda,etc). International design studios located in Southern California were well represented, they were allowed to have fun and showoff their creativity, very slick aero concepts and unique suspension technologies. They had a short straightaway in Irvine and longer road course Tuna Canyon hill in Malibu. Check out their advanced ideas and designs (2005-2007).

Xtreme Gravity Racing: Soapbox Derby meets Formula 1

https://vimeo.com/1997214

World-record gravity racer uber design.

https://www.youtube.com/watch?v=j6Ygh0YyREA

Goodwood Festival of Speed; more for fun, shorter wheelbases and handling more important.

https://www.youtube.com/watch?v=Wi7UUPrQ7_A