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Re: Open Source Racecar
Posted: 09 Nov 2019, 14:54
by Tim.Wright
maunde wrote: ↑09 Nov 2019, 14:12
Hey Tim, that all seems to make sense to me, however, given that you will already be having a large proportion of understeer due to your COG, would you not want to reduce this at low speeds?
All valid points as far as road-car practicality from what I understand.
May I ask what your experience has been like working in Europe and moving there from Aussie?
The rearward CG creates (dynamic)
oversteer tendencies not understeer. With such a large rearward bias, the compromise is always between dynamic stability and mid-corner understeer. In this battle stability always wins because it's simply more important (for a human driver at least. Robot drivers are another story) and that's why rear-heavy cars often have a reputation for mid corner understeer. Not because of the weight distribution directly, but because of the actions you need to take to keep the car dynamically stable (roll balance, roll steer, camber recovery) all induce steady state understeer.
Additionally, a reaward weight bias will also introduce delays into the reponse of the lateral acceleration and yawrate build-up which drivers interpretate in many different ways but understeer is one of them. My guess is that this is the reason why front tyres appear to be typically "oversized" for vehicles with large rear weight distributions - to increase front tyre cornering stiffness to try to mitigate these delays.
Regarding moving from Aus - it was pretty much the only option if I wanted to work in the automotive industry. I had zero contacts in Europe so it was a slow process to build up experience and contacts but it all seems to have worked out ok for me.
Re: Open Source Racecar
Posted: 09 Nov 2019, 22:41
by maunde
Tim.Wright wrote: ↑09 Nov 2019, 14:54
maunde wrote: ↑09 Nov 2019, 14:12
Hey Tim, that all seems to make sense to me, however, given that you will already be having a large proportion of understeer due to your COG, would you not want to reduce this at low speeds?
All valid points as far as road-car practicality from what I understand.
May I ask what your experience has been like working in Europe and moving there from Aussie?
The rearward CG creates (dynamic)
oversteer tendencies not understeer. With such a large rearward bias, the compromise is always between dynamic stability and mid-corner understeer. In this battle stability always wins because it's simply more important (for a human driver at least. Robot drivers are another story) and that's why rear-heavy cars often have a reputation for mid corner understeer. Not because of the weight distribution directly, but because of the actions you need to take to keep the car dynamically stable (roll balance, roll steer, camber recovery) all induce steady state understeer.
Additionally, a reaward weight bias will also introduce delays into the reponse of the lateral acceleration and yawrate build-up which drivers interpretate in many different ways but understeer is one of them. My guess is that this is the reason why front tyres appear to be typically "oversized" for vehicles with large rear weight distributions - to increase front tyre cornering stiffness to try to mitigate these delays.
Regarding moving from Aus - it was pretty much the only option if I wanted to work in the automotive industry. I had zero contacts in Europe so it was a slow process to build up experience and contacts but it all seems to have worked out ok for me.
Thank you for enlightening me in regards to oversteer vs understeer, I was always of the impression that more highly loaded rear tyres tends to result in more understeer and vice-versa. Would you suggest any good resources for further learning VD?
Cheers!
Re: Open Source Racecar
Posted: 09 Nov 2019, 22:45
by Tim.Wright
maunde wrote: ↑09 Nov 2019, 22:41
Would you suggest any good resources for further learning VD?
Milliken or Guiggiani are the best by a long way.
Avoid any motorsport based stuff if you want to learn VD stuff properly.
Re: Open Source Racecar
Posted: 20 Jan 2020, 21:41
by marslo911
Little off top guys: Is anyone here from Birmingham or Tamworht ? i've got some ideas to work around with somone local.
Many thanks!
Re: Open Source Racecar
Posted: 03 Nov 2022, 09:35
by deepred
I've only very recently discovered this forum, and I can't thank you enough for the Busso V6 CAD files. I'm a hobbyist 3D artist/modeller using mostly Blender & DAZ Studio, and when I render pictures of cars, I like to depict a high degree of engine & interior detail. In this case, I have a number of Alfa Romeo 3D models this engine could easily slot into.
Re: Open Source Racecar
Posted: 03 Nov 2022, 22:04
by johnny comelately
deepred wrote: ↑03 Nov 2022, 09:35
I've only very recently discovered this forum, and I can't thank you enough for the Busso V6 CAD files. I'm a hobbyist 3D artist/modeller using mostly Blender & DAZ Studio, and when I render pictures of cars, I like to depict a high degree of engine & interior detail. In this case, I have a number of Alfa Romeo 3D models this engine could easily slot into.
A very good ambition and I hope you get a job at ChronosGP
Re: Open Source Racecar
Posted: 24 Apr 2024, 03:23
by XSR buggy
just came across this thread as I was doing research for my project which is similar save for the fact mine wont have a full body. not sure anyone is still active on this but has there been any progress?