Castor Angles...

Spent the last couple of hours googling and reading about castor angles and castor correction...

Thinking about my own Jimny's front end, where I've got approximately 5"s of lift attained with JimnyBits +4" diesel springs with a set of my 1.5" spring spacers on top... I reckon with the extra weight in/on my Jimny that this should give me about 5" of lift...

Now, carrying on thinking, I've got the ORA / OffRoad Armoury's front castor corrected radius arms (the later square ones like they've been made from Girders) which are, I believe, from memory corrected for +4" of lift (indeed Martin's listing which appears to be a copy and paste from the ORA's original description would back that thought up - www.bigjimny.com/store/castor-corrected-...adius-arms-p189.html )

Sooo... I was just wondering whether my Jimny would benefit from a bit more castor correction?

Reading Rhinoman's Spec page - www.rhinoman.org/suzukistuff/info/tech/jimny_tech.html - says the factory caster angle is 1 degree 55 mins, but how can I measure castor angle with my tyres on the ground?

With the new Maxxis Trepador 31"s on, I feel the steering has gone a little 'vague' (a bit like steering a bouncy castle?!) and I'm in the process of trying to correct this with Zanfi's +80mm front drop pitman bracket and a similar sized drop pitman arm (with the addition of a Rockwatt custom made front stainless panhard rod with a kink in it so that the two Zanfi components will sit together without the panhard fouling on the drop pitman arm). All these components should get the drag link on the steering and the panhard rod to sit more closer to parallel with the axle and therefore restore the working angles of the suspension geometry...

But I can't help feeling a bit more castor correction with some offset bushes may also help?


Any ideas / comments appreciated...?

Or am I over-thinking this?

Other areas to consider? Upping the tyre pressures due to the bigger sidewalls? Which are possibly giving the Jimny more 'bounce'? Winding up the AVO adjustable shock absorbers valving a bit?

Dave

Put caster correction bushes in your caster correction arms.

supergaz wrote: Put caster correction bushes in your caster correction arms.

How high is yours Gaz? Looks high in your Avatar...

What have you done on the front of yours?

Cheers
Dave

Weight wise I've winch/ ora bumper/ 6 point cage/ big aux battery so its heavy. Sitting on 5yr old +3 Jimnybits springs, ORA +4 correction arms and a +2 bodylift. I did have your orange 1.5 b4v spacers years ago but decided it drives better sitting lower on suspension and 31's with more virtual lift with zuki Andy arches to Finnish.

Increase in tire diameter = lower rolling resistance and reduced scrub radius = lower caster to diameter ratio,

Calculate the difference in percentage from standard diameter tires to the new size tires and increase the stock caster by that percentage. And that's over and above any correction thats added for ride hight , keeping in mind you are under castered at the moment.

Also with wide contact tread design like on the treps and other width consistent tread patterns it pays to slightly over caster to avoid tram lining.

So im doing the right thing having 4' correction arms on 3' springs with my 31' tyres. I defiantly wouldn't go higher than +3 on suspension again and if I was to build my Jimny again I wouldn't do a bodylift either to keep COG as low as possible.