[WIP MOD] Sunniva (open-wheeler)

[Knut Omdal Tveito]

I've been working on a new mod for about a month now. This time it's an open-wheeler with a straight 4 engine.

I have made the engine architecture flexible so that a displacement of 1.2-2.0 l is possible. The gearbox is a transverse layout and the drivetrain is designed to cope with just over 450 hp so that I can use it in other applications. The final drive and gears 2-5 is positioned for easier access when changing ratios in the garage. Reverse and 1st will be a fixed ratio.

The engine, transaxle and some of the suspension is final, although I wish to make a new gearbox casing that is more integrated with the suspension.








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[Knut Omdal Tveito]

Thanks Hans and Tom.

I've finished the brakes now. The wear rate I used is taken from a scientific paper and I have chosen to keep the disc temps somewhat low (~275 deg C) to increase the disc life. I chose the Tarox Corsa brake pads for good brake feel and good performance in the relevant temperature range. Finally all the GTL brake parameters are based on calculations and experimental data.

I also made a steering rack and radiator. The radiator model is simplified but has the same mass as a C&R radiator that is suitable for this car.

There is also a Varley Red Top 15 dry cell battery in place.

The car weighs in at 397 kg at this point and the center of gravity has moved 90 mm forwards, resulting in 42.3 % front weight distribution.

Next up is a the dash, steering wheel, gear shifter and finally i will replace the mock-up spaceframe with a final version. Not much left now

I've made a GTL version as well (only physics, no model). I tried it with the 2l engine and the suapension and mass of the CAD model. This thing is seriously quick! You really have to watch the throttle, even in third gear. I think I'll go for the 1.5l for the first release




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[Stuart Thomson]

Niceness! :good:

Gonna be a monster

 

[Knut Omdal Tveito]

The body is coming along nicely. Next up is steeringwheel, dash, seat and replace the mockup fueltank. This car will have a small fuel tank of 50-70l behind the driver, but if more fuel is needed later I'll make two slim tanks either side of the drivers legs.



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[Stuart Thomson]

Looking very good mate :good:

 

[Niels Pedersen]

That is so cool! I think I'll dedicate the next 40 years of my life learning 3ds!

 

[Ondrej Kapal]

I am saying it all the time but top work! I am so much looking forward to drive it

 

[Hans Sneep]

What a beauty Knut ,can't wait to hear an feel !!!

 

[Knut Omdal Tveito]

Thanks guys!

Made some GTL models tonight, mostly to test and see how it looks. Some of the models (uprights, calipers, suspension, wheels) are final, but the textures are very much WIP However the rear wheels will be a little bigger, but same design. Something happened to the suspension on one side but I think I know the reason.

I must inform you guys that I am colorblind (mostly red-green-brown). So if you see some weird colors in this thread, please tell me!!!






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[Knut Omdal Tveito]

Made some progress with the suspension today. Suspension arms are now final. Will revise the uprights next to suit the new suspension model. Next up is gearbox and engine.

I got a lot of spare time the next few days so hopefully the models will be completed faster than the last week.




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[Knut Omdal Tveito]

More models ingame now. Still some work needed with textures and material properties. The suspension will also look better when I start working on the tire physics.





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[Ross McGregor]

Looks good so far, looking forward to trying it out!

 

[Bob Hutchins]

Keep it up Knut, nice to see it taking shape.

 

[Knut Omdal Tveito]

Made a new dash, cockpit and body this morning. The modeling is pretty much finished now, but I need to make some better textures. As you can see from the picture of the cockpit the suspension doesn't match and isn't moving. But I don't feel its that important now. In fact it is pretty hard to finish this car because it's so much fun to drive now





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[Ondrej Kapal]

dont let me say that again.. just...

amazing work Knut !!!!!

 

[Hans Sneep]

Great to see it coming along Knut,one comment I miss a Rollbar lol

 

[Knut Omdal Tveito]

Haven't posted in over a week but thats because I've been running simulations. The aerodynamic model is almost complete now. I've simulated 15 scenarios (pitch/rideheight-sensitivity, sideways/reverse/vertical motion). Only 4 simulations left now:
-two more yaw angles
-2 cases of slipstreaming

When the aero is done there is only one thing left - tires. I will try to model the tire with the Finite Element method, taking into account all the different plies, bands, rubber compounds etc. With this method scientists have obtained good correlation with experimental data (only 5 % deviation). Hopefully I will get good results and we are all done and ready for some betatesting

Here's an example from the CFD simulations where the yaw angle is at an extreme 30 degrees:


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[Carlos Diaz]

Holy crap Knut, are you a modder or a scientist? lol

That stuff there looks complicated man.

It looks like we might be bringing a little bit of GPL into GTL, sweet!

 

[Knut Omdal Tveito]

Lol Carlos. I just have a passion for cars - both driving and engineering.

Would be great if it could capture the GPL action. At the moment the car feels very close to the iRacing Skip Barber, but that might change when the new tires are on the car.

I've been looking for 65' laptimes lately and i stumbled across some weight figures. My car weights 451 kg which compares very well with the lighter cars of 65':
Honda RA 272 - 497 kg
Lotus 33 - 451 kg
Brabham BT17 - 460 kg
As for lap times the car does 1:25 around Kyalami, but that is with some temporary tires with a little too much grip. Jim Clark set a 1:27.2 in 1965 and I think the final car will be closer to that time.

Aero is finished now as well. Hopefully I will start working on the tires later next week.

 

[Carlos Diaz]

I wish I had 10% of your skill and knowledge, really.

But maybe it's good that I don't know what you know, because it would probably cause my wife to leave me lol.

 

[Knut Omdal Tveito]

Couldn't resist trying out the tyre model before I went to sleep. Here is the results of a simplified simulation (only ~5 min to solve). Looks pretty sweet





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