Suspension questions

[dearthvader]

I'll try to keep this post as short as possible.

I have an ez-go RXV on which I originally installed a 6 inch MadJax lift kit. I hated how stiff the ride was so I installed a Jake's double a-arm kit for the front and then several months later built a 4-link rear suspension setup. The coilovers I used for the rear are from a Polaris sportsman 500.

The setup works great in that the suspension absorbs bumps significantly better than the prior setup and both the front and rear suspensions articulate quite nicely. The problem lies in the amount of body roll when cornering which is causing significant understeer and of course an unsteady feeling to the passengers that comes with leaning. Most of my riding is on pavement but I occasionally ride off road.

I've been scratching my head trying to figure out this problem. I thought maybe the spring rate is not adequate. On the front suspension, however, the coilovers are adjustable and I've put quite a bit of pre-load on the spring, enough so that when the cart is empty the shock only compresses about an inch of the ~ 6 inch travel. If I tried a spring with a higher rate the suspension likely wouldn't sag enough to get the base ride height at ~ 40% of the shock travel.

On the rear suspension I noticed the spring rate for the coilovers was too much as the shock had zero compression from the weight of the cart therefore I had to trim the spring by about 1 inch to get the stock ride height to 40% of the shock travel. I mounted the rear coilovers as far to the side as possible to help alleviate body roll. So, I have a cart that absorbs bumps like a Cadillac but leans like a monster truck.

Someone suggested I need better performing shocks that allow me to adjust rebound and compression rates. While that may be true I can't imagine that would fully fix my body roll problem.

I thought about fabricating front and rear sway bars and I'm willing to do so if necessary but I wanted to reach out for advice first to see if I should make changes in the coilover springs first. example: should I buy longer coilover springs with less spring rate so that I can attain the 40% sag but the spring gets stiffer quickly since it is compressed at a higher percentage of its length than a spring w/ a higher rate that is shorter? Should I look at progressive rate springs?

The universal problem golf carts have that most vehicles don't is that the suspension has to be setup for a larger envelope of weight than most. As an example my Rxv empty weight is probably only about 750 lbs as I have a lithium battery. When 4 adults get on the cart the weight doubles.

Any advice is appreciated.

[slonomo]

Did you fabricate a panhard bar with your 4 link? Pics?

The upside to a good 4 link is articulation.

The downside to a good 4 link is articulation.

You need an "anti-roll bar" or "anti-sway bar" to keep it from leaning. For rock crawling, you don't need one. But for high speed cornering you do.

[dearthvader]

Thanks for the reply.

I did not fabricate a panhard bar - it is a triangulated 4-link so the lateral stability is good.

As far as a sway bar is concerned I decided I'll build one from 1/2" schedule 80
pipe as a proof of concept and if it is inadequate I'll later fabricate one from more expensive tubing. I'll likely be building a sway bar for both the front and rear. Any advice on fabricating the sway bar? I intend to buy a pipe bender so that I don't have to weld anywhere on the pipe except maybe the ends for link attachments.

For some reason two of the images keep appearing upside down - I believe this is a buggiesgonewild problem.

[slonomo]

Nice setup! I think you'll find the anti roll bar to be the ticket, almost every vehicle on the road has one. You could use some quick disconnect links just in case you want some extra articulation?

I have a 3 and 4 link suspension thread, as I am also considering this type of suspension setup. Seems most off road vehicles are equipped with some type of a 3 or 4 link, so I figured why not. I bought all the ends already, just need to decide on what tubing to use. What tubing did you use for your links?

https://www.buggiesgonewild.com/showthread.php?t=153805

[dearthvader]

I learned the hard way and bought 1.5 inch DOM. Don't make that mistake, it is much easier if you by 1.25 inch as the availability of bungs is much better. Most off-roaders use 1.25 which is overkill in terms of strength for a golf cart.

[Shepard]

With what you've built sway bars would be the answer, getting the whole weight of your vehicle working for you.

[jhnmflr]

Nice job! i really need to get the 4 link rear done sometime.