radius arm vs 3link

[dbeverett]

My ifs surf just isnt cutting it anymore so im looking at SASing it, I've started collecting parts, front axle, longs etc and realised I have NFI what suspension to put under it.
I don't really do the most extreme stuff but I definitely want to be able to comp it in the future but its a daily at the moment so still needs to retain abit of streatability.
I'm going backwards andforwards between 3link front and dual-tri 4link in the back but im worried about onroad handling with this setup and how it would behave in off camber situations (they scare the shit out of me!)
Radius front and rear is about a thousand times easier to make everything, heaps less work on the actual truck and decent onroad handling but then im worried about offroad, heard they can be prone to unload in the front on hill climbs and I've seen some pretty nasty wheel hop from the radius setups.
So anyone have any opinions/advice/warnings/names to call me?
Would all be appreciated as im currently completly lost

[ISUZUROVER]

Well set up RA suspension will give good manners on and off road. Have a look at the Disco 2 which has RA + Panhard front and RA +Watts link rear.

HOWEVER - RAs really limit wheel travel offroad a LOT. This is because of binding at the axle end when the axle tries to rotate relative to the RAs. Having the axle end bushes closer together helps improve wheel travel (possibly at the expense of handling on-road).

[Mr DJ]

I find mine a very good compromise for wheeling and on road.
It's fairly well balanced, RA front end with the std Surf 4 link + panhard setup running longer rear coils. With 4" lift it still feels pretty stable and have not laid it over for a nap .... yet.
Did the Logan Challenge with it and didn't break anything, drove it home ... we won a couple stages too



If your concerned about on road handling, IMO go for a RA setup for a stable front end.

[SIMMO84]

If you space the plates 10mm wider on the diff end you reduce the binding. I'm considering radius arm front and rear for my hilux if I ever get around to finishing it. there was a build up on here a while ago I'll try and find it.

[TheBigBoy]

If you SHORTEN the space between the control arm mounts on the housing it reduces the binding.

[uninformed]

If you SHORTEN the space between the control arm mounts on the housing it reduces the binding.

now are you talking about the bush spacing on one arm? ... or the distance between both arms at the diff end?

[brooksy]

If you SHORTEN the space between the control arm mounts on the housing it reduces the binding.

now are you talking about the bush spacing on one arm? ... or the distance between both arms at the diff end?

My guess is the arm bolt separation on diff end.

& I agree with the other point on reducing mounting width at chassis slightly. I was given this tip a while ago & current build is going to be the guinea pig (so to speak)



brooksy

[uninformed]

Strangerover did it on a buggy he built ages ago, used stock LR arms and cranked them in....from what I can remember was the flex was good but a little funky handling???

[80's_delirious]

If you SHORTEN the space between the control arm mounts on the housing it reduces the binding.

now are you talking about the bush spacing on one arm? ... or the distance between both arms at the diff end?

My guess is the arm bolt separation on diff end.

& I agree with the other point on reducing mounting width at chassis slightly. I was given this tip a while ago & current build is going to be the guinea pig (so to speak)



brooksy

I'd love to know how this works out for you Brooksy, I started a thread about this idea ages ago, I'd love to try it on my own car someday.
I reckon it could work well if done cleverly.

[TheBigBoy]

Ive done it already.

It drives fine. But sadly you will have to wait for the results .

Ps. You cant make the control arm holes closer on each arm. You will need to make custom arms and it will suffer diff wrap bigtime. 25% seperation of tyre size to control diff wrap.

[80's_delirious]

bigboy, have you changed the mounting position at the chassis end? Hope it works for you.

from your pics, what you have done is not quite what I had in mind, I was thinking having radius arms triangulated, ie set up like so \ / narrowed spacing at the chassis, same spacing at the diff but angled back to the chassis. along with wider spacing inside the diff mounting plates to prevent binding between plates.

I believe this is along the lines of what strangerover did previously.

[TheBigBoy]

Yep, I understand what you meen. I didnt want to alter my chassi mounts though. Shortening the distance between the housing brackets was the next best thing for me. It was a last minute decision and if it didnt work. Id just build a new housing. It hasnt affected the handling at all. Drives better now than with caster correction arms. But you will have to wait and see about the travel.

[dbeverett]

That looks good with them tucked right on like that, I imagine itd get pretty decent flex.
If I was to move the bushes closer together on the arms id only do one side, one side would control axle wrap and the other would allow flex, similar to a 3 link

[TheBigBoy]

Why wouldnt you just buy superflex arms then. Thats what you just discribed.

[dbeverett]

They cost a gazillion dollars more than I want to spend and are designed for another car?

[brooksy]

Mmmmm, I don't think closing up the arms at diff is going to help flex.
I am closing in at chassis with a max of 30mm overall (15/side). As the arc at X flex has the diff rotate under (in towards chassis) when at droop. I am only going to have 3 1/2" up travel but 11+" droop so having the chassis point in marginally should in theory help twist binding. I have lengthened the arms mounting point at chassis back 125mm & have chosen a separation bush distance at axle of 175mm which is inbetween L Rover (165) & 80 series (185). I have the front/upper bush located at 12 o'clock & the lower bush is roughly between 7-8 o'clock. My arms are also 25mm wide Bisalloy 360 & I will be running GU bushes at axle & 80 series at chassis mount.
As everyone probably has seen I am doing a complete custom RA set-up on the front of Shortman's Lux so I have the ability to build without limitation.


brooksy

[TheBigBoy]

Mmmmm, I don't think closing up the arms at diff is going to help flex.
I am closing in at chassis with a max of 30mm overall (15/side). As the arc at X flex has the diff rotate under (in towards chassis) when at droop. I am only going to have 3 1/2" up travel but 11+" droop so having the chassis point in marginally should in theory help twist binding. I have lengthened the arms mounting point at chassis back 125mm & have chosen a separation bush distance at axle of 175mm which is inbetween L Rover (165) & 80 series (185). I have the front/upper bush located at 12 o'clock & the lower bush is roughly between 7-8 o'clock. My arms are also 25mm wide Bisalloy 360 & I will be running GU bushes at axle & 80 series at chassis mount.
As everyone probably has seen I am doing a complete custom RA set-up on the front of Shortman's Lux so I have the ability to build without limitation.


brooksy

I think everyone will have to do the old reliable arm trick. Arms in front of you, elbows into body and thumbs up. Rotate 1 arm up and the other down in an arc replicating control arms. Keeping elbows locked into body. Stop when you think binding will accure. Now move hands closer together and do it again. Stopping it at same binding possition.

Helps the travel bigtime. The fact that their closer together allows for more tuck and drop, even when binding at same possition. And no, the arms dont touch the chassi.

[uninformed]

im still not seeing it....so with your example, would that make narrowing the chassis end limit artciulation more than keeping them parrallel? I would like to see your results, but unless you do it with the only difference being inboarding the axle end the results could be scewed...I think you would need to cycle it without springs or shocks either

[TheBigBoy]

I would think moving the chassi mounts further back will do more than going inwards.

But yeah your right. I did the flipped arms at the same time. So its hard to tell how much affect it had alone.

[uninformed]

flipped arms does not change anything except for clearance

[TheBigBoy]

Wrong...

[uninformed]

Wrong...

what does it do then?

[1MadEngineer]

Wrong...

i see your wrong and raise you a wrong!

[Struth]

Wrong...

i see your wrong and raise you a wrong!

I will throw another wrong in the ring too, flipped arms only increase clearence..

[TheBigBoy]

Ha ha, Ive seen this debate. I know your right greg. With the points of force in regards to contact patch, centre axle point and chassi point. But now after I have done this mode. The front end drives atleast 50% better on road than the superflex arms. Suspension travel is definately better aswell. Its much more free to flex. So clearance isnt the only thing.

I never commented before on this subject, just read. Mostly because I didnt know. Im just giving my results. And they matched what everyone else has said who has done this mod. Have you guys done this? Or just playing on calc's?

[gu town]

The way I see it, flipping arms would do two things. 1) improve crlearance, as mentioned. 2) Improve the arc in which the wheel travels when hitting a bump by flattening the RA's out.

Apart from spacing the diff mounts apart (NOT the distance between the bushes on the RA) when you change them around I dont see any other way it would help with flex.

[Struth]

The way I see it, flipping arms would do two things. 1) improve crlearance, as mentioned. 2) Improve the arc in which the wheel travels when hitting a bump by flattening the RA's out.

Apart from spacing the diff mounts apart (NOT the distance between the bushes on the RA) when you change them around I dont see any other way it would help with flex.

The only thing that improves/changes the arc of the axle is the relationship between the RAs mounting point at the chassis and the centre line of the axle.

So either drop boxes or suspension height change will alter this relationship, flipping the arms alone does nothing.

As for flipped arms giving better artic' possibly.

[TheBigBoy]

Its very hard to discribe. Its more the deflective angle it takes when it hits a bump. Unless youve ridin in 1, its hard to discribe. But its kinda the same a going from 31" tyres to 35" tyres. How the bumps feel different. You dont feel the small ones anymore, but still do the big ones.

[1MadEngineer]

Its very hard to discribe. Its more the deflective angle it takes when it hits a bump. Unless youve ridin in 1, its hard to discribe. But its kinda the same a going from 31" tyres to 35" tyres. How the bumps feel different. You dont feel the small ones anymore, but still do the big ones.

sometimes referred to as diff regretion...

[TheBigBoy]

The way I see it, flipping arms would do two things. 1) improve crlearance, as mentioned. 2) Improve the arc in which the wheel travels when hitting a bump by flattening the RA's out.

Apart from spacing the diff mounts apart (NOT the distance between the bushes on the RA) when you change them around I dont see any other way it would help with flex.

The only thing that improves/changes the arc of the axle is the relationship between the RAs mounting point at the chassis and the centre line of the axle.

So either drop boxes or suspension height change will alter this relationship, flipping the arms alone does nothing.

As for flipped arms giving better artic' possibly.

Not shit stiring. But flipping the arms alone does give more travel than stock. Everyone who has done this has said it. And from what I have seen of my own. Its true.