3 link or 4 link?

[Warthog]

Been looking at Jeep front ends and their liking to use 4 link rather that 3. Seen a few ramp tests this year and the Jeeps with there 4 link set-ups can get some serious twist. The LR fraternity seem to like the 3 Link set-up, why is this?

3.4 link set-ups, whats ya opinion and thoughts on set-ups?

Cheers Mark

[filthy boy]

Been looking at Jeep front ends and their liking to use 4 link rather that 3. Seen a few ramp tests this year and the Jeeps with there 4 link set-ups can get some serious twist. The LR fraternity seem to like the 3 Link set-up, why is this?

3.4 link set-ups, whats ya opinion and thoughts on set-ups?

Cheers Mark

4 links in the front are difficult to package with the correct triangulation and geometry around the engine / sump. 4 link rears are quite straightforward, Standard LR is geometrically a 4 link with the uppers coming to a single mounting point on the axle.

3 link is easier although still hard to get the geometry right in the front and you get a single link taking a load of stresses / forces.

Biggest difference in performance is that 3 link still needs a Panhard rod to locate the axle laterally. With lots of travel in the suspension this will make the axle swing in an arc and thus affects handling as the front moves out of line with the rear. However, loads of comp buggies in the US run this setup even when not required by class rules so it works.

4 links are more adjustable for roll centres, roll axis etc assuming they are the right geometry to start with and not just mounted any old how that fits. A properly built 4 link should give you much less roll steer and better toporsional control of the axle.

If you run crossover steering then you get bump steer issue with both. Unless you run full hydro (or something else we are working on at the moment ).

FB

PS I have double triangulated 4 link front and rear but the engine is way way back!

PPS both can be built to flex like mad on an RTI ramp but that does not translate necessarily to real world performance.

[Bush65]

...3 link...you get a single link taking a load of stresses / forces...

Yes when the single link is the lower link, but not when it is the upper.

...4 links are more adjustable for roll centres, roll axis etc assuming they are the right geometry to start with and not just mounted any old how that fits. A properly built 4 link should give you much less roll steer and better toporsional control of the axle...

A 3 link can be built to give the same roll centre, roll axis and roll steer as a 4 link. Generally the constraints on how the geometry can be set-up are the same.