Control arm torque

[just primer]

Just a quick question. Why does everyone always say torque the control arm bushings with the car on the ground? I realize that they probably squish out with the force and the pressure on the bolt is different, but is it really that much different? Can we get an engineer to say: if they need to be set at 90 on the ground then set them at 80 in the air, that will compensate for the average load per square inch or something like that. Maybe I can place the back end on car ramps or something. I need to try a different setting on my traction bars.

Have a great Memorial day. Thank you to all that have served. Hope you eat a big steak today, and don't take your family for granted. It seems like my son shapes his whole life around making good memories with his dad.

[clshore]

If you tighten while in the air, when the car is down the rubber in the bushings will be permanantly stressed in torsion.
Not so great for the rubber over the long term.
Also, on lighter cars, can actually affect the ride height, thus, alignment, handling, etc.

[Bob Hollinshead]

What bushings are you using? the oem style bushings will be stressed if not torqued under load but many of the aftermarket bushings it makes no difference.

[just primer]

Fairly new, OEM rubber in the back. Poly in the front. The rear has homemade boxed in control arms ( aftermarket factory plate for the 442 style and a welded steel strap over the uppers), the lowers are on relocation brackets from UMI. I don't get any wheel hop anymore, trying to get a good launch on ET streets at the track. I drove out to the track on them so I kept them at 32 psi, maybe I should have taken them down to 20. They don't wrinkle but I might get a little better grip. I am a new comer to the 1/4 mile, I have drove this car for years on the street. (72 Cutlass, 455, TH400 SP, B@M shifter, 3.90's, Edelbrock Aluminum Heads and intake.)

[pdq67]

May I suggest going all "poly-graphite" and be done with it.

And if you want to go farther, then install grease zirk's(Sp?) and needed grooves everywhere and grease away.

Guy's daily drive SC&C's front A-Arms that use steel to steel by greasing them at oil change time. And this was the way that it was done back when I was a pup................

I want a pair of SC&C's front A-Arm's but it will be a while before I get with Marcus..

pdq67

[peejay]

You only have to worry about it for rubber bushings where the inner sleeve (what you're torquing against) is bonded to the rubber.

If you have plastic bushings with an inner sleeve that is free to rotate in the bushing, then it does not matter.

If you have plastic bushings with NO inner sleeve, run away! You'd think people would know better, but I've seen high dollar super-sweet tubular control arms that used NO sleeve. Nothing to tighten against so they relied on using Nylocks. Trying to tighten them just resulted in bending things. And they clunked and shifted around like a SOB. Shameful!

[crazyman]

Hmm. So bushing torque positions can alter how a car turns left by strategically placing jackstands at various heights can make a difference..