Creating and developing a 2wd buggy
 

Really happy to start this project. This will entail everything,from getting know-how to design it to getting the design to fruition. Most of the concepts are done by yours truly so I will start sharing them in this thread now that I've done fixing the mercedes F1 car suspension design*. Also here will be shared my testing logs so everyone can read and give input. Right now I will contact in hopes of creating a CAD group to design the parts I need and then off to the test mule.

The test mule will be a TLR22 with some 2.0 parts and parts I and the community come up with. Yes I want your input to create a car.

*Might dreamed that :lol:

First let's present the car and the ideas behind it.

This car is meant to be cheap and simple (minimal parts, 3d printed and cnc or router made) yet stand shoulder to shoulder against offerings from the big brands. Aimed to be completely legal and use standard electronics of course.

It will use transmission and damper parts readily available. The only thing it will be different from the norm is the suspension, it will be a multi-link arrangement front and rear, with minimal suspension set up adjustments (wheel alignment, camber gain and ride height compensation) to make it simpler and less compromised than current designs. A similar example is theoriginal Losi JRX2 rear end, https://www.youtube.com/watch?v=WhS_gx71XWw.

Depending on price I'm aiming to produce one kit variation max (high and low grip variants).

best of luck and with all of your in depth knowledge I'm sure it'll be great!!! Following the thread!!

Thanks! Can't wait to produce a prototype.

I have a JRX2. Actually, I have many of them. I got my first one in 1988 and have had every variation of the JRX. I've got tons of spare parts. I also have a 22 2.0. I've looked into doing a custom 22 2.0 chassis with the 5 link rear end. It actually wouldn't be that difficult. You'd only need a couple of custom parts. I even have a carbon fiber chassis blank with a 20° nose kick. I've just never gotten around to actually doing it.

I will say that the 5 link is the ultimate low grip rear suspension. On low grip, nothing can touch it. On high grip, it has so much rear grip that you can't get the car to turn well during on power corner exit. You'll just lift the inside front tire. Most tracks today are high grip and the 5 link won't work well.

Hello 30Tooth,

Would it be possible to implement the Losi JRX2 Rear Suspension assembly to 1/8th scale Buggy?

Cheers.. :)

I've got that covered and you can tune it better if you think about it, even without using a roll bar :)

Hello Professor,

Yes you can, the SH Z car had something similar but not as advanced ;)

The JRX multi-link was adjustable with RPM aftermarket parts. You could adjust toe and antisquat and of course the camber link.

That would be no issue as stock it will include turnbuckles to take care of that.

Also, the JRX2 rear end rolling to much in high grip is in my perspective a non-issue, as one wouldn't run a rear motor in high grip tracks. I'm not designing a rear motor car :)

P.S.: If someone has TL XXX parts and ship to EU let me know (BK2 parts mainly).

With a balanced suspension, it doesn't matter if its mid or rear motor. Roll amount is a function of geometry, not where the motor is.

Exactly, I kept everything the same when wheel rate had to be balanced again.

That means I have to consider putting a roll bar on my design...

Hello Guru,

The first outing of the Z-Car was using an asymmetric Rear Arm pivot points. I heard the impression from racers who were running the car at that time was how good the rear traction was.

But.. If it is good, then why the designer opting back to regular A-arm configuration for the next model?

Cheers.. :)

The rear grip was indeed abundant, the problem is when it becomes too much. You have to balance front and rear grip, it's all that the car needed. Looking at the rear upper link configuration it could be further refined as it has a small issue. Speaking only of suspension geometry that car is still good.

The biggest thing to overcome on a 5 link setup for current tracks is the variable anti-squat affect you get from the drag links. The longer you make them, the smaller the change in the anti-squat affect would be. Sway bars would only help with the roll aspect, but wouldn't help with the car squatting in a straight line.

On a 5 link setup, it's the forward links, or drag links as you call them, that determine the anti-squat. You can move them up or down to affect the level or longer and shorter to affect the rate of change. However, you can also move them in relation to each other. On one of my JRX2's, I have the RPM mounts. They have different locations for the forward links. If you move the ends towards each other, rather than trying to keep them parallel, that will also affect the rate of change. Anti-squat is far more tuneable on a 5 link system than on an a-arm system. A problem with the JRX2 was that Losi didn't allow for any way to tune them. They also had limited camber link locations, and they were short, so the amount of camber gain was quite high. Later on, as they updated the series with H-arms, additional camber link holes were added on the rear bulkhead. RPM also came out with the side mounts that allowed roll center changes and there was also a shorter link that allowed for a small amount of toe adjustment. The original car had none of that. With the exception of the camber link locations, you had no control over rear toe or anti-squat.