Can you have too much caster?

[drohweder]

So I am putting a lift on the truck. can I go with the castor plates and not the bushings with 850/863 combo as I anticipate more height in a couple of years---like slees 4 inch kit?

 

[Jay Johnson]

Yes,
Too much castor will cause castor wobble a vibration in the steering wheel at speed. Sometimes it can get pretty bad. The steering effort will go up also but with power steering that shouldn't be a problem.

On the plus if no wobble is present the extra castor will give it better high speed stability.

I assume you mean too much Positive castor negative castor is bad.

Jay Johnson

 

[Pin_Head]

You can run into problems with too much caster, but I doubt that caster plates would cause a problem with a 4 inch lift. The main problem with too much caster, is that you reduce your contact patch in turns, so you are more likely to slide out in high speed turns or on slick surfaces, It also increases wear on the inside and outside edges of the tires.

 

[landtank]

with that spring combo you might consider adding a front spacer to level out the truck some which would negate some of the caster gotten from installing plates.

 

[drohweder]

Thanks guys. The plates provide about 5* castor correction, bushings are 2-3* So it woiuld be an intentional +2* with the plates. I plan on running 850/863 combo (heavy) and will likely go larger in a couple of years when the truck is no longer a DD. I guess the only what to know is to install and drive.

Usually the problem is not enough caster...so I know this is a bit backward question.

Thanks.

 

[Toyole]

I got the J-lift (850/863) whit plates and no bush corrections. The plates give me about 3,4* castor.
I have put in 25mm spacers on top of my frontsprings too.
The car is great to handle, some heavy in low speed, but great on road.

 

[Tapage]

if you like level stance .. why not J in front and 863 rear and go ahead with slee caster plates ..

 

[Jay Johnson]

You can run into problems with too much caster, but I doubt that caster plates would cause a problem with a 4 inch lift. The main problem with too much caster, is that you reduce your contact patch in turns, so you are more likely to slide out in high speed turns or on slick surfaces, It also increases wear on the inside and outside edges of the tires.

With positive castor the camber change only occurs when you turn the wheel and it leans the tire into the turn. As long as the wobble doesn't occur it will actually increase cornering ability. I have no experience with stiff sidewall big tires but soft sidewall big tires like lots of camber in a turn. No way you can get too much castor in one of them before wobble sets in. Also the weight jacking effect of the castor will help move cross weights to stabilize the car in the corner. As long as no wobble and you don't have too much steering wheel effort you can't have too much castor.

Jay Johnson

 

[Pin_Head]

Caster angle can have a positive effect on the contract patch in turns, but it depends on the tires and weight and you can over do it and decrease high speed turn stability too. You see caster specs of + 6-10 degrees on some high performance cars, like the Honda S2000 and the Nissan GTR. The tires on these rice rockets are very different from the ones people typically run on FZJ80s. The engineers that design cars know all about this and that is why they have a particular caster spec. My point is that it is not wise to second guess them.

 

[SiRaDuDe]

I've always had a doubt if you really had a pronounced stink bug look, I mean having the rear way higher than the front.

Could this also affect your Caster? (into the negative area)
it should atleast affect the Steering axis inclination. (which FSM shows to be 13* +/- 45')

and if it does can someone in this situation gain some positive caster by lowering this rear lift?

Just wondered sorry about the hi-jack

 

[Pin_Head]

Yes, "stinkbug" effects caster by the angle that the frame is off from horizontal. Could easily be a degree or two.