[zuk85]

Ok finally decided on the 50mm Jimnybits lift. been tossing up wether to get the 75mm or not but nahh..

Just wondering what degree castor correction bushes will be best suited to this lift if anyone may know?
also has anyone on here gone with the trailmaster shocks?? or best get the es1000?

cheers

[joel]

50mm, none.
from what i understand.

[stockman]

Why not the 75mm?

[monley]

joel wrote:

50mm, none.
from what i understand.

Yes, from the dick heads in most shops will tell you. You can get away with it, but 3-deg would be best for 50mm JB lift IMO. Then again, i would go 75mm spring's with castor corrected arms

[joel]

really, didnt realise that.
that chages my mind on a few things.
cheers
joel

[smiffkid]

3 degree really is to much for a 50mm lift. There is such thing as over castor. And that makes them drive worse.
If ur worried put the lift in and get a castor check done.

[zuk85]

I really wanted to try do the castor, lift and such all at once was hoping to figure out the casotr before hand.

We have a aligner at work and can do that no worries but as above. if it comes to it though might have too..

blokes who get the 40mm OME lift i think put 2degree's in... not 100% on that.


Also on the 75mm lift im just more freaked out about being done over by standing out more lol also dont want to get the centre of gravity to high. We only have 30mm lift atm with 235's, and its a decent height atm nothing to write home about though.
Im really only gettin the lift so i can put my damn ARB bar on finally, fronts have sagged as it is so with the bar on OH MY GOD IT WOULD SCRAPE ITS BELLY!!! ha ha ha

[GRPABT1]

To much castor will only cause heavier steering (or load on the power steering), some tyre wear and otherwise it's all benificial. Positive castor will give straight line stability at speed and dynamic camber when turning. I've got my commodore loaded up with as much positive castor as I can before the tyre fouls on the body, makes the manual steering heavy but stays stable above 200km/hr.

[NuttyNath]

I have a 50mm lift in mine with 2deg iron man
correction bushers Drives allright steering return is Much
Better and the bushers straitened out the springs a bit to.
They were Relatively easy to fit with the press at work.

[royce]

GRPABT1 wrote:

To much castor will only cause heavier steering (or load on the power steering), some tyre wear and otherwise it's all benificial. Positive castor will give straight line stability at speed and dynamic camber when turning. I've got my commodore loaded up with as much positive castor as I can before the tyre fouls on the body, makes the manual steering heavy but stays stable above 200km/hr.

Go learn about suspension design, why doesn't your average race car run a billion degrees castor?

[GRPABT1]

I've built a race car that runs alot of positive castor based on what an entire series of race cars like mine are built like. Perhaps you should practice before you preach.

[squibby]

monley wrote:

joel wrote:

50mm, none.
from what i understand.

Yes, from the dick heads in most shops will tell you. You can get away with it, but 3-deg would be best for 50mm JB lift IMO. Then again, i would go 75mm spring's with castor corrected arms

I second Monley.

I got 2.5 degrees on my 40mm lift and it ain't quite enough, but it's fine for me. Yeah you will be told you don't need, but you do really if you want less understeer and longer tyre life. My jimny is transformed with the castor correction.

(Positive castor if preferable to negative btw. Many cars are designed with slight positive castor - take a look at old mercedes, but Nothing wrong with neutral castor either.)

[joel]

GRPABT1 wrote:

I've built a race car that runs alot of positive castor based on what an entire series of race cars like mine are built like. Perhaps you should practice before you preach.

its practive WHAT you preech.
and to much of anything isnt a good thing.

[GRPABT1]

Sorry, grammar Nazi

And yes within reason of course but in this instance a lifted Jim is going to gain some negative castor over stock so a 2 or 3 degree bush won't be overboard. I run around 3.5 degrees positive in my fast car and I know some blokes who run 5 degrees but they run power steering and I don't.

[joel]

GRPABT1 wrote:

Sorry, grammar Nazi :P

And yes within reason of course but in this instance a lifted Jim is going to gain some negative castor over stock so a 2 or 3 degree bush won't be overboard. I run around 3.5 degrees positive in my fast car and I know some blokes who run 5 degrees but they run power steering and I don't.

just annoys me like when ppl say "anyfink" or "nuffink"
im not sure i will bother with 3deg of caster correction on a 2'' lift, time will tell if thats a good choice.

[royce]

GRPABT1 wrote:

I've built a race car that runs alot of positive castor based on what an entire series of race cars like mine are built like. Perhaps you should practice before you preach.

Commodores? come back when we are talking about cars that corner.

When you run positive Castor, it makes the tyres wish to self center faster, just cause they prefer to be in a position that is neither pointing too much left or too much right doesn't mean the car will track straight either, just that the wheels will point as much ahead as they can

The dynamic camber you talk of is something worth expanding on, the more castor you have the more the outside wheel will tend to go negative camber when turning, as the pivot points that are leaning back when pointing straight ahead look more like leaning in once the tyre turns around the front of it.

Depending on how your front end reacts to bodyroll and what the geometry does, this can result in very strange handling, though if the front end is designed to take it into account then it might work well, but seeing anything designed to go ground corners fast has a lot of negative camber static I would say thats never really worked out for anyone.

[GRPABT1]

You would say or you've set up a race car before? I never said my car didn't have negative static camber as well, but that was not the topic of discussion. Nor is my car and it's abilities or the fact it would probably give anything you've got a run for it's money around a circuit. My point was to convey that a little more positive castor is not a bad thing with my car just as one example. Not going to get into a keyboard warrior argument over race suspension that I've personally had experience with, in a car mind you that regularly gives the imports a hiding, albeit far from standard.

[Gwagensteve]

I do think there's an interesting point Royce is raising here. I've had problems with death wobble after adding caster. Adding lots of caster to a live axle car is different to adding lots of caster to an IFS car with static camber.

I'm not arguing either way and don't want to get into a keyboard warrior argument over this issue, but arguing that adding caster to a live axle, radius arm car with no static camber is effective because you've found it's effective on an IFS car with static camber is a long bow to draw, no?

Steve

PS I think camber correction bushes are retarded.

[monley]

Castor bushes suck. While they might get the castor angle back within factory specs, it really messes with the spring while flexing. Castor corrected arms are a much better optoin + you will get the WB back that you lost from the lift. Then again, this isn't so much of a issue with only a 2" lift...

[GRPABT1]

Gwagensteve wrote:

I do think there's an interesting point Royce is raising here. I've had problems with death wobble after adding caster. Adding lots of caster to a live axle car is different to adding lots of caster to an IFS car with static camber.

I'm not arguing either way and don't want to get into a keyboard warrior argument over this issue, but arguing that adding caster to a live axle, radius arm car with no static camber is effective because you've found it's effective on an IFS car with static camber is a long bow to draw, no?

Steve

PS I think camber correction bushes are retarded.

Much more valid point than Royce's rant. What are your experiences with death wobble and castor Steve?

[Gwagensteve]

I've seen added caster result in death wobble. It disappeared once I removed some caster. I don't have any figures.

Steve.

[gman74]

I have just put a 3" JB lift with radious arms, I can't complain about a thing. I don't have that mush mechanical knowledge but I was ale to install it my self in a day. Sits realy nice and drives beautifuly, on and off road.

[royce]

GRPABT1 wrote:

You would say or you've set up a race car before? I never said my car didn't have negative static camber as well, but that was not the topic of discussion. Nor is my car and it's abilities or the fact it would probably give anything you've got a run for it's money around a circuit. My point was to convey that a little more positive castor is not a bad thing with my car just as one example. Not going to get into a keyboard warrior argument over race suspension that I've personally had experience with, in a car mind you that regularly gives the imports a hiding, albeit far from standard.

I would say you have nothing to offer this place and this thread is another example, now youve backpeddled

youve gone form no problem having too much, to a little bit more is a good thing

I just got offered a $50 donation to Rushos fund to ban you for a week, wonder what I would get for permanent?

[monley]

royce wrote:

GRPABT1 wrote:

You would say or you've set up a race car before? I never said my car didn't have negative static camber as well, but that was not the topic of discussion. Nor is my car and it's abilities or the fact it would probably give anything you've got a run for it's money around a circuit. My point was to convey that a little more positive castor is not a bad thing with my car just as one example. Not going to get into a keyboard warrior argument over race suspension that I've personally had experience with, in a car mind you that regularly gives the imports a hiding, albeit far from standard.

I would say you have nothing to offer this place and this thread is another example, now youve backpeddled

youve gone form no problem having too much, to a little bit more is a good thing

I just got offered a $50 donation to Rushos fund to ban you for a week, wonder what I would get for permanent?

I'll chuck in another $50 towards a permanent ban

[atari4x4]

i haven't donated yet, would another $50 help get the ball rolling?

[GRPABT1]

I wouldn't give a fuck anyway. Glad there is some charity going on, you should donate it regardless. Pity you had to get so butthurt and wave your little ban stick around to feel tough though.

[Mike57]

To get back on topic. I have a 40mm lift on my Jimny. After the lift was fitted I had negative 1 degree of castor and a steering shudder at about 70kph which only developed after fitting the 215 tyres as well. The Suzuki Castor spec is close to positive 2 degrees. (+/- 1 degree). I fitted 3 degree castor corection bushes (and yes I know Steve thinks these are retarded) after fitting I got positive 2.4 degrees of castor.

The increased casor did give the steering a slightly more positive feel in that it centred better but overall I did not notice that it was particularly heavy. There was some improvement in the shudder with the increased castor as well although it was not removed completely. At least I was now back close to the factory specs. I suppose the message is that while it is often said that a 40mm or 50mm list does not require any castor correction the measurements that I have all from the same machine with the same operator show that the Castor is affected by this mild lift.

My suggestion is to check the alignment before and after the lift as I did an go from there.

Mike

[Gwagensteve]

Thanks for bringing some real data to this thread Mike. I wouldn't expect anything less

My dislike of caster bushes is that they increase roll stiffness, either through material (urethane) or due to the effect of the offset bush providing less material to be squished when articulated.

On balance, for predominantly road use, having correct caster is more important than the lost flex but for predominately road use there's no need for lift. I really don't think they are a good solution because they sacrifice roll stiffness to get alignment in spec. I'd be interested to see if it was possible to use a "caster bush" at the chassis end to roll the arm down enough to correct caster without binding up the axle end, where all the squish is done.

Steve.

[OVERKILL ENG]

Hi all .. Interesting thread and discussion;)
This is only my opinion on the caster issue and death wobbles..
2-3degrees positive is what we have found to be best , anymore either way and yes you can get the wobbles BUT most of the time it isn't the caster causing the wobbles.. The wobbles alot of the time is incorrect preload on the trunion(swivel) bearings once you get past the desired castor angle then the lack of preload on the bearings becomes more exaggerated and wobbles ..
Now after running bigger Tyres for a while and a lots of wheeling the bells on the diff actually start to close up and you can't get the right preload on the bearings so an easy fix or bandaid as such is to run 1mm toe out as this will put load on the trunion bearings and will stop the wobble ..
And I agree with steve castor bushes are more trouble than they are worth
Sam

[Gwagensteve]

I'd agree that most of the cause of death wobbles is kingpin preload. Like most adjustments on a Sierra, they need to be tighter than people think.

Steve.