WIP Beta released Backyard Kart

Yay, now I can make ridiculously fast drag configs without the tires causing instabilities lol

 

It's a little difficult to handle due to no wheelie bar, but you'll be able to make this with this update. 15x14 Dragger wheels on the rear and 15x4 on the front.

 

Update on update: I was trying to sneak in a new mesh before the end of the weekend, but aligning it with the bodykits has taken more time than I anticipated. I will be making that my task for the day and if it is not done, I will exclude it from this update. Although I may exclude it anyway since it is a fairly face-dense mesh at around 60k faces for one part and even though I don't see any performance hit using it, it may affect those with a slower system than I have.

The mesh in question is a new engine mesh for the 1000cc engine. I found a decent mesh for a Ducati v4 and started working on getting the scale right and reducing the face count. The image below is how it currently looks in blender. I also took the handlebars and the rear brake meshes to be used at a later time.


EDIT: I got it looking okay. I added a new engine labelled (New Model) if you want to see it. Below is how it looks in game on the lowered kart

 

Update is uploaded! The only issue I could not resolve and gave up on, for now, is the minor vibrations on the electric rear axle. It does not really affect handling, which is why I chose to leave it as it is for this update. The new engine mesh is WIP, so expect it to be significantly changed in upcoming updates.

 

With the new update in place. It appears that no major issues have cropped up for once! I am going to be spending the next bit of time working on various parts of the kart, but focusing on the tires. They feel really close to normal tires now, but I want to continue getting them closer. I also plan on adding another engine that is a middle ground between the 750 and 1000cc engines since the difference between the two is extreme. I was looking at various engines and found a CBR900RR that looks to be right about the middle of the two with a redline of 11k and 91 horsepower. Preliminary testing of the torque curve puts the performance of the short course config on par with the Dunekicker on Crandon while remaining relatively easy to handle.

This mod is getting a lot more content-dense than I had initially planned on, but it has been a great outlet for testing stupid or interesting ideas in a semi-realistic way and has been a great learning tool. I don't really see there being an end to the development of this kart due to how modular it is. Due to the simplicity of the construction, adding new parts is relatively easy, so almost any idea I have can be added with little effort. The new independent rear suspension setup is an excellent example of this since it was a completely new geometry and the hardest part was the mesh lol.

So to summarize:

Plans (Not necessarily to be included in the next update):

• Front Suspension:
  
  • Continue fine-tuning the geometry
    • At this point, it's just going to be minor tweaks to the precompression values
  • Work on coilovers
    • When they break, the helper nodes go crazy
  • Work on limiters and breakgroups
• Rear Suspension:
  • Continue fine-tuning the geometry
  • Work on coilovers
  • Work on limiters and breakgroups
• Frames:
  • Work on deformation
    • Currently, it only likes to deform front to back
• Dummy:
  • Center:
    • The right leg likes to flop around way too much
    • I want to find a way to better stabilize the head so the camera doesn't shake so much
  • Offset:
    • The right leg is limp
    • There are some vibrations that I cannot find the source for
• Engines:
  • Work on thermals
  • Work on the new mesh
• Tires:
  • Work on stability and handling
• General:
  • Revive wide config
    • The parts have not been updated with the new alignment tweaks since the values the wider arms will need will be significantly different from the standard.
    • I plan on having a unique mesh for the widened suspension instead of just extending the arms.
  • Fine-tune bodykits
  • Work out how to add a camera for configs that do not have a seat.
    • To prevent the camera from being placed inside the dummy, I based the camera on which seat was selected.
  • Other issues or ideas I come across

 

You know what would be the coolest thing ever? If I set the maximum steer angle to be actually full instead of 80%. With this change, the slower karts now turn significantly sharper. I was prompted to check how to improve the turning circle due to making an experimental map of an indoor kart track and finding that a few of the turns were way too sharp for this kart. I set the max steer angle in the jbeam to full and all of the sudden the kart can now turn significantly sharper.

 

I hit another breakthrough with the tires that allows me to use much higher values on the tires without them getting unstable or losing low speed performance! This is going to bump up the next update to as soon as I can get all of the kart tires edited since the changes are incredibly significant. The v10 config is now about as hard to drive as the HR Welded Front Race config used to be instead of being entirely undriveable.

Edit: The trick is the precompression. I didn't want to touch that before, due to not really understanding its purpose, but it suddenly hit me that these tires have sidewalls that are at best half the height of standard race tires. So essentially, even though I was using the same weight and wheel node counts, the tires were still unstable because the precompression distance set at 0.99 for a tire with 4 inch sidewalls should be set at most 0.98 for the kart tires. I set them even lower, though, and now the ultra tires have very little instability at normal speeds. The fish-tailing does not occur until 150 through to 160 mph and stops afterward.

 

Lets get the changelog together:

Front suspension:

• Welded Front:
  • Further refined precompression values
  • Made the wheel height adjustment more precise
• Added new suspension geometry
  • Referred to as "Alt"
• Wide:
  • Updated wide suspension

Rear suspension:

• Raised Rear:
  • Changed the beam spring of the connection to the frame
• Wide:
  • Updated Wide suspension

Tires:

• Kart tires (4x4 and 4x6 rims):
  • Refined the tires
    • Now there is a significant difference between the Hard and Soft tires. Soft tires have much more traction, but the Hard tires allow for a higher top speed. This is accomplished without changing the friction settings.
      • Soft tires can get up to 2Gs with the 250cc welded front
      • Hard tires get up to around 1.7
    • The ultra tires are now significantly more responsive at low speeds and still stable up to 150mph
      • Also done without changing the friction settings or using friction values greater than those found in vanilla tires.
      • It is possible to reach up to 5Gs around a corner with these tires on the HR welded race config.

Engines:

• Fuel:
  • Added new fuel tank parts
  • Separated twin tanks into left and right.
  • Can mix and match lower and upper configurations and choose to only have a fuel tank on the right or only on the left
• Raised Rear:
  • Changed engine mount beams
• Exhaust:
  • Updated weathered exhaust texture

Seats:

• Changed beam connections to the frame

Dummy:

• Fixed instability of the offset dummy

 

Post weekend update:

Mesh progress is coming along a lot more slowly than I anticipated, although I think this will be worth it since now there will be an engine model for each type of engine in this mod (I1 kart, I1 moto, I1 scooter, I2 moto, I4 moto, V4 moto, and Electric Motor). I am still tweaking tires as well and have started on two new projects while I unwind from the constant mesh adjustments. Those projects are an indoor kart track map I am working on importing from an Assetto Corsa mod as well as a dedicated race kart frame. The new frame might end up being an entirely separate vehicle, but for now I am going to be using this dedicated frame to test the tires since it will have a very different and more standard jbeam.

Currently, the kart's welded front end is essentially what it says on the tin. I took the jbeam from the standard suspension and added support beams to keep the arms from moving with the only real node changes being that I removed the suspension mounts and the front subframe is also really narrow compared to the rest of it, so it is really easy to twist and is naturally floppy. Using this new frame will help to reduce or eliminate that variable as well as allow me to use a significantly lighter vehicle (90lb frame vs 200).

Having more than two dedicated kart courses (currently Elvadalen and Motorsports Playground) will also give me a more diverse set of track types to test the handling. Elvadalen has a mix of banked and flat corners, but is relatively flat, Motorsports Playground's course is very dynamic, but all corners except for the first can be taken full throttle in the 250 and 350cc variants. This new course has a bunch of elevation variance and many tight corners while still retaining a lot of speed. Since I found a ton of cool looking courses, IRL and through models online, I might make a map with a bunch of kart tracks since they are really compact for the most part.

Although I want this next update to come as soon as possible, there is a lot of testing and tweaking that I need to do before I can happily release this one. The previous post will still act as the changelog for the existing kart frame and this post will include images for the new projects as they become more polished.

Edit: I just saw on reddit that someone is making a standard race kart. I think I will still work on this one for testing purposes, but I will be keeping an eye on that one

The kart in blender:

 

I spent the day yesterday tweaking the standard kart frame and came to the conclusion that it doesn't do anything that the backyard kart doesn't. Due to this. I have put the new frame to the side for now and may make it into its own mod someday. I have been making good progress with the tires, though. The new top speed for the HR race welded front config is 160mph and it's getting really close to formula 1 speeds with a 1:47 on suzuka whereas the slowest F1 record is 1:34.

I am still going to be working on the kart track map, which won't be anything super detailed, but it will have several tracks that can be driven to. So far I have three indoor and two outdoor courses being worked on with only one of the indoor courses being not based on a real course. This map mod will not delay the release of the new update and in fact, it has been helping me fine-tune the tires and the chassis of the low-end race configs.

 

I feel like I am spamming this a bit with not a whole lot of progress, but I am finally getting to the point to where I can get the wheel and tire weights to where they need to be. Currently, the wheel assembly for the 8x6 rim and 22x11 tire weighs somewhere around 40-50 lbs where IRL it'd weigh closer to 20. The key to this change is the ray count. Previously, I tried to keep the ray count as high as possible since the tires are small, which resulted in forcing higher spring values in the wheels AND tires, which necessitated a higher weight. The higher spring was necessary due to the extremely small distances between the nodes, which meant the smallest amount of compression could lead to the wheel folding in on itself. I reduced the ray count from 16 to 10 on the 8x6 rims and from 16 to 8 on the kart rims and as of now I have the 8x6 rims and 22x11 tires at their realistic weights. What this means for the next update is that lower tier config performance should be improving significantly due to a drastic weight reduction to the order of 80-100lbs, all configs will be a bit more stable, and the wheels shouldn't fold in on themselves at the smallest bump. The downside is that since I no longer have the huge weights damping the powertrain, the vibrations due to my bad torque reaction setup are much more noticeable.

 

good luck with the progress , i am sorry if this seemed like a lazy response after you typing paragraphs of text but i don't really know what else to say

 

Thank you! It is really appreciated. I tend to ramble because I kind of suck at writing succinctly and I want to include as much detail as possible lol

 

I am making progress on getting the new tire weights stable. There is a lot of tweaking I am needing to do to keep the tires and wheels stable during a crash, so there is a ton of time I am spending testing tweaks. In order to test the tires in a variety of courses, I am throwing together a collection of kart tracks that I alluded to earlier. The four indoor courses are ports from Assetto Corsa mods and the three outdoor courses are from satellite data with some props from the related Assetto Corsa map mods. I am awaiting approval from the original modders before I release the map, but I am working on putting it together nicely and am currently working on the layout of the courses. As soon as I can confirm permission from the original authors, I will begin putting this together in earnest.

This is the (WIP) layout for the outdoor courses.


This is the layout for the indoor courses (No texture on the upper left due to experimenting with export methods):

 

seeing how close that driveshaft is makes me think this should have direct drive now for the lolz, apparently a lot of early karts were setup that way (no clutch or neutral)

 

The engines I chose all had internal transmissions, but that would be pretty cool to try. Gotta push-start the kart lol.

Here is an updated image of the new 1000cc engine mesh. It was the first one that I was able to find the exact location of the output shaft because for some reason, it seems people dislike taking pictures of the left side of bikes lol. I still need to realign the exhaust, but I am still working on simplifying the engine mesh.

 

Status Update:

I have the tires mostly stable now, but there are some edge cases during particularly hard hits that cause the tires to end reality. I cannot provide a time for that to be resolved as I am still in the investigation stage of figuring out the problem.

I have also made some strides with texturing the engines. I started working on a new technique to hopefully add more definition to the engines without relying too much on high-res textures or adding too many unique textures. Texturing the engines has been hard since I do not want to bloat the file with too many textures and I still want the engines to look as good as possible. I have chosen the route of using generic textures (all made by myself) that each of the parts pulls from, which so far has worked out okay, but I am getting close to a real 1.0 version of this kart and want to take it to the next level.

Below is a new new version of the new 1000cc mesh It is starting to look a lot more like the engine it is based on, but I need to change out the random circles for proper bolts and motor mounts. Please ignore the carbs as they are leftover from the part selector and will not be present in the final version :



On the other hand, I am making progress on the new map and so far have gotten permission from 3 out of the 7 creators of the original mods. I am working on optimizing the ones I have permission for so far and it has been a lot more difficult than I anticipated for the indoor courses. This is due to how they set up the elevation changes. The method they used involved an infinitely thin road mesh on top of a support mesh. This worked okay for a while, but with the kart tires being really sensitive, any unusual or non-closed edges anywhere near the road mesh resulted in the tires being shredded. To fix this, I am making a custom collision mesh that will remove this problem altogether without sacrificing the detail of the courses.

 

So I almost have the tires ready. They are still a bit bouncy, but they are stable at most any speed this kart is capable of reaching. I am also almost done with the engine meshes and have just a few face-dense areas to clean up on the i4 engine.

I was doing a bit of research on racing kart tires and stumbled upon the formula student racing series. They use a variety of engines, but it looks like the most commonly used is the engine from a Suzuki GSX R600, which I have added to the kart. It uses the I4 engine mesh, but it uses an edited B4 sound, which sounds fairly close to the Suzuki. New engines going forward will have to fit into the category of either, 1 cyl, I2, I4, or V4 as I do not have the desire to work on any more engine meshes lol.

I also have made some progress with the map. I have finished two of the indoor courses and have started on one of the outdoor courses. The indoor courses are very tight and only suited for this and similar karts.

 

I figured I'd make a quick video to show the new tires in action as well as the layout of one of the courses in the new map. The video is fairly low quality, but it does show the handling characteristics.

The tire meshes are edited versions of those found on the FR17. For now, they will match the color of the frame so I don't need too many textures for it. The wheel meshes are custom made racing kart wheels. I still need to model a hub for them, but they look good for now.