I'm garbage at developing cars pls send help

Long story short: I made a car in automation that handles questionably despite my best efforts not to. The one characteristic I'm talking about is its' tendency to oversteer dramatically under heavy trail braking. And I have no clue why that happens. Rear brakes are significantly smaller than front ones, braking distribution is waaaay up front, rear sway bar is relatively soft and this little mofo still decides to play tricks on me. I attach zipped .car file, if anyone has some spare time please take a look at it, or drop some suggestions under this post.

 

This belongs in Content Creation does it not?

 

I'm at work without access to checking out the car, so my advice will be a bit generic.

Put a big wing on it. Automation's aerodynamics section doesn't do anything for BeamNG since BeamNG uses the shape of the body and parts to simulate aerodynamics. That will make high speed trail braking much more stable.

Also, increase the size of rear tires. This will make slow speed trail braking more stable.

Another consideration is simply the fact that trail braking is a very precise skill and if you're using a controller or cheaper wheel, it'll be very hard to get the inputs right for trail braking.

 

Decrease your rear anti roll bar stiffness and increase your front a bit as well as the advice from above...

 

This should help to get started with aerodynamics part:
https://www.beamng.com/threads/is-y...ecially-at-speed-intro-to-aerodynamics.56379/

 

I don't really know tbh, never made any mods before.

Well, rear tires are already quite wide for the spec I'm going for, and wing is not really an option for this car, it's modelled after first porsche sports car, so wing is just not alright there. I guess I'll have to go for downforce undertray (or whatever it's called) if I haven't already. And I've been using controller for past 600+ hours of gameplay, so I can handle myself sometimes.

Been there, done that

Well, thanks, but I already know a thing or two about aerodynamics and it's not what I want to be using for this particular car, since it's modelled after the first porsche that wasn't a beetle or WW2 tank.

 

Don't except that you will have what you input in Automation in BeamNG, verify, test, check.

Is current aero of car what you designed in Automation or is there difference? What about spring frequencies?

 

Ohhhh.... that explains it. Its rear engined isn't it? If that's the case... you probably aren't doing anything wrong... you just have to change your driving style. Rear engined cars are actually notorious for doing stuff like this. You have to be conscious of weight transfer and keep in mind that you can't just sling the car into a corner while braking as the large weight of the rear end will just push it around on you. Try driving it like a motorcycle... roll onto the throttle a little bit through the corner to load the rear suspension. The front will stay gripped up because the suspension is so soft from no engine, so just start pushing the gas further and further... if you keep that rear end loaded, you should be able to clear the corner.

Try cranking up your rear camber and suspension stiffness/damping... That should help keep the rear under control a bit better. I would tell you to increase your deceleration differential lock but I don't know if you can do that.

 

So far I haven't made any changes, now I'm kinda struggling to get repository to cooperate, I deleted some mods and now it wants to download them all, yay /s. When I sort that mess out I'll get back to developing that car of mine
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Well, I made it to be rr layout, but switched to fr. It was even worse then.

 

Did you change damping after the switch?

If not, then that would explain why it would be worse.

I have also one vehicle that has problem with rear suspension, it bugs out so that it is kinda super stiff, hence my suggestion to check out these things.

 

Well, I simply chose Sport suspension preset after layout change and worked my way from there, so I guess it shouldn't be from that

 

Could you upload the Beam.NG car folder? I don't have Automation to export the .car file.

 

I don't trust values calculated by that quick setting.

I did look and on braking I saw 50-60kg on rear wheels, only, that is 100-120kg weight at rear.

Remove rear ARB, set front springs and damping bit stiffer, increase front ARB to at least double of current, set tire pressure in BeamNG LOT lower. Then try to increase or lower rear damping by one and testing each damper change. Ride height might need lowering too.

I got it to work somewhat good, but still edgy as hell, it is quite light and I don't know if my controlling and beamNG likes light so well.

Also aero does play part in there, imagine you have 30kg lift and only 50kg weight per rear tire, that is quite big percentage something like 30% I guess.

 

Hmm, something is wrong with forums' servers or my internet and I can't seem to get it uploaded. I'll try to send it again tomorrow. I'm back to setting it up tho, so final product should be quite a lot better I hope.
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Well, that was somewhat my point, getting it as light as possible. I guess I don't even need to get back to it since you say even after some more tuning it's still edgy af. I don't know, maybe I will revise the car completely.

 

It worked today. Anyways, I somewhat scrapped this car, have really no hopes for it. But if you still want to try it out then have fun.

 

Some of my cars have been really poorly working too, most with solid axles, but some with double A rear has been nasty too, not sure if it is in geometry, but some might not be possible to make handle.

Try multilink rear, even that is quite unrealistic for your vehicle, maybe it can reveal something, never had problem with that suspension type.

 

Well, honestly we can't be expecting much from those cars. They are after all an import from different game and we can't reasonably expect them to perform as well as vanilla cars or one of them nice mods that get featured. Also, I'm kinda lacking the proper tuning of suspension, just like in rally or race coilovers from beamng. Spring values, slow and fast bump damping, thresholds, all that good stuff. Either way, I played around with automation some further and made myself a very promising car, from year 1950, on those funny cross ply tires that bend to the point it looks like they are about to slip from the rims.
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BTW, you seem to know a lot about automation. Do you perhaps know if there is a way to port setups from old Kee engine to unreal4 to export them to beam? I've got some sweet cars there from a few years back and I wouldn't mind trying them out.

 

I have no idea really, only thing that comes to my mind would be exporting / save as in kee and put file to import folder of UE4, if Kee even has export function. You might need to search from their forums, if there is a way, I'm sure they have it figured out.

Update: For suspension tuning options, you would need to add variables to Jbeam, check out rally pessima jbeam files for idea how to do it.

 

I built little evil thing, 170hp rear engine, it seems that even with small spoiler thing, there is still enough lift to make car unstable when speed goes over 130kph:


That is made lot worse by the fact that front end get downforce, which makes steering very sensitive.

 

You may want this.