gq castor questions

[mudmav]

hey guys i know the deal with options for castor correction ie: bushes plates boxes arms. What i want to know is what should my castor be for the car to steer and handle nice. at the moment its at -2.5 i know it should be positive but by how much.

thanks guys

[JBE]

Factory is 2deg plus minus half a deg from memory. I run 0 deg with 0 toe in and 33" tyres and it works reasonably well. O road the truck seems to follow grooves in the road surface, but it's not annoying.

The castor actually depends on the wheel size as well.

Cheers
J

[mudmav]

so basically i dont have enough negative castor to run 5 degree plates then but i hav to much to run 3 deg bushes. so sounds like im F*c*ed then. what are my options?????

[badger]

pos 2.5 is still ok .......... most true stockers have +2.5ish

wouldnt wanna go to much further tho

for what its worth id buy drop boxes myself

[mudmav]

here what i figure if i puit plates in then its gooing to be +3 if i put 3 degree bush in then its only going to be +0.5 so its going to be fairly average either way. how much do drop boxes correct castor

[its aford not a nissan]

drop boxes are only good for 4 inch or higher lift but if you have 4 inch plus lift go drop boxes they line up catsor well and take pressure off the rear radius arm bushes to give more drop

[badger]

they are directly proportionate to the lift as the space the back of the arm down as far as the lift spaces the front down

eg 4 inch lift use 4 inch boxes and you will have same castor as your car will have stock

[mudmav]

so does anyone do boxes to suit a 3 inch lift

[JBE]

You should be fine with 3 deg offset bushes for a 3" lift. I use them in my 5" lifted trucks and it works reasonably well there.

[oondy]

I build Drop Arms to suit 3" 4" and 5" lifts.

I did some drawings and this is what I found:

from stock ride height to 2" lift, the front diff rotates forward 4deg.

then for every 1" after that it is another 2deg, so if you fit say a 6" lift and only fit 7deg plates your still out by about 5deg (12deg without castor correction.

but as its been said earlier, some bigger tyres don't require as much castor correction to make it driveable.

My drop arms return the castor and spring seats to factory positions.

cheers

OONDY

[RoldIT]

I build Drop Arms to suit 3" 4" and 5" lifts.

I did some drawings and this is what I found:

from stock ride height to 2" lift, the front diff rotates forward 4deg.

then for every 1" after that it is another 2deg, so if you fit say a 6" lift and only fit 7deg plates your still out by about 5deg (12deg without castor correction.

but as its been said earlier, some bigger tyres don't require as much castor correction to make it driveable.

My drop arms return the castor and spring seats to factory positions.

cheers

OONDY

Can you explain in a little more detail how you came to this conclusion?

Reason I ask is your results go against everything people have been working from in the past. Your degrees numbers sound pretty high to me.

Cheers.

[oondy]

All I did was measure the factory arms and drew them into Autocad. I then rotated the diff end so that the vertical distance was 2". Then, using the angular measring tool in Autocad i measured the angle or rotation, 4deg for 2" lift.....and so on for 3,4 and 5" lifts.



Sorry I was a bit out on the 2deg for each 1" after 2", but it's still more than I first thought.

I think that certain castor plates/bushes are used with respective lifts because they probably bring the castor back to a bareable setting, but more often than not it wouldn't be back to factory specs - close enough though.

cheers

OONDY

[badger]

how much are your front arms oondy
and wheres the pics:P

id say that your calculations are correct going by my experiances.
but every car seems to be different for some reason

[mudmav]

so how much for a set to suit my 3 inch lift you measurement s seem to add up with what my car has done. and also hwo do you fit them ie bolt on or weld on and how much do they hang down from the chassis. as i dont want to loose to much i have heard people say 90mm and that more than 3 inches so that would mean that i have just lost the clearance that i gained with the lift.

[MARKx4]

Here is a link with pics from 4wdmonthly
http://www.4wdmonthly.com.au/forum/show ... hp?t=21817