I was going to use onyx's thread but I thought this would be more useful by itself...

I just installed my z10 bars and am in the process of determining my preload preferences. I know I need to get an alignment after/during preload to make sure both sides are equal in castor/toe. I thought of a good way to accurately measure preload on bothside instead of just "number of turns", which I don't believe to be accurate as the same # of turns on each side doesn't nessesarily equal the same force.

I believe a torque wrench with a crowfoot attachment on the milled ends of each bar would be a good way to measure. Something like this:



I don't know what size it takes yet, but I'll let those interested know.
What do you guys think?

Also some questions. I called z10 but Geoff, their engineer/tech guy, is away for awhile I guess....

1) After preload, castor will be out of factory specs by a little? Will it be negative or postive in respect to specs? Value?

2) How will this affect handling in terms of turn-in response, etc?

3) How many "turns" did you guys use as preload

4) Please confirm that the arms should be shortened = inward force on the suspension.


Thanks for all your ideas and input

Ed


[Modified by sackdz, 3:20 PM 12/6/2001]

 

My understanding is that it won't take it out of spec as set forth by Honda/Acura. Yes when you adjust the bars, adjust them so they get shorter.
I'm trying to findout the number that the caster should be at when preloaded ideally. I don't know if there is a magic number where everyone's caster should be set at for it to be ideal.

 

I put 3 turns on mine and went to the alignment shop.

Both sides were at 1.1 degree positive(?) castor exactly . . .

 

The bars should be turned to shorten

I have 2 turns of preload on each bar

Caster barely/if any changes because the bushings are being moved but the LCA is not moving. NOTE: I don't like the idea of pulling on the bushing to try and adjust caster. With 2 turns of preload on my car the caster was the same as before I started, only the toe was affected.

HTH Mattj

And the torque wrench Idea would not work for a moving part like the radius rods themself because its not loading againt anything, it is spinning freely on threads until a certain point, which is probably farther than they should be turned.



[Modified by Dropspeed, 3:38 PM 12/6/2001]

 

Toe in or out should not be affected at all. It is caster that is ultimately being altered. Think of the top of the shock tower as the pivot. As it pulls on the lower control arm it compresses the front outer and inner rear part of the LCA bushing while pivoting at the top of the shock tower. The wheel all the wile maintains the same plane as caster is positively increased. This part doesn't in anyway turn the tires left or right; therefore, no change in toe is seen.

 

I disagree, there is still torque on the bar when you turn it. The farther you go, the harder it becomes to turn. This resistance is what I'm trying to measure and equalize for both sides, although I don't know how much it really matters.

 

Makes sense, BUT NO. I have access to an alignment rack and do all of my own alignments. When I made 2 turns on the Radius Arm on my ITR only the toe was affected the caster was not. Try it on a alignment rack and you will see.

Ed, The problem with the torque wrench is that is on my Z10 kit one of the rods is harder to turn than the other, could be crap in the treads, but I have taken them apart and greased the threads and it is still stiffer than the other which would through off the readings.

Mattj


[Modified by Dropspeed, 10:07 AM 12/7/2001]

 

Same with mine, but I wonder the cause.

Assuming both bars are equal, I suppose it could be a slight difference in suspension settings for each side... frame being slightly off, I dunno. But if the suspension is equalized beforehand, and the frame is perfect, equal torques on suspension components, equal weight distribution left/right, equal tire pressures, it would work .

Wait, half that **** isn't true

OK It won't work