Traction Arms

[xsv_32]

Was browsing trademe the other day and saw a set of R32 adjustable traction arms for sale. Ive been searching a bit but cant find a discription on what they link from and to and how they work when you adjust them?

Any info would be cool as im aiming for a big hp streeter and dont want to spend all my time trying to find grip!

[STATUS]

they help stop the dynamic change in toe over the suspensions range of travel.

[MookRG]

How exactly would you tune them, i bought a set ages ago and took them out cause i didn't know what to do with them

[Sydneykid]

To correct the rear camber on the rear of an R32/33/34 you need to adjust both the upper control arm and the traction arm. If you don't adjust them in tandem you end up with excessive bump steer (ie; the toe changes as the wheels go up and down). This uncontrolled toe changing disrupts the tyre's contact patch with the road and results in less grip and nervous handling.

BTW, the name "traction arm" doesn't mean that they directly affect the tyre's traction. As described above, their effect on the tyres grip level is secondary and in very much in tandem with the upper control arm. The word "traction" actually refers to their effect in controlling the fore and aft movement of the upright (hub).

One of the (many) reasons why I dislike the use of adjustable arms is the almost total lack of understanding by DIY'ers and many wheel aligners of the side effects of adjusting the length of a control arm to correct camber. You would be very lucky to find an alignment shop that even has a bump steer gauge, let alone someone who knows how to use one. Adjusting the traction rod length to correct the bump steer is a painstaking process, one that the requires both the equipment and the skill/knowledge/experience to use it.

The standard Nissan upper control arm and traction arm combination is pretty much the best matched length for minimising bump steer. Which is one of the (many) reasons why I prefer to use adjustable bushes to correct camber. If you adjust the eccentric to the same degree on the upper control arm and the traction arm then you will end up with no more bump steer than the car has standard.

Cheers

Gary

[Abo Bob]

Does lowering the car change any of that Gary or do static changes to toe put you back to where you were before you lowered?

[Sydneykid]

Does lowering the car change any of that Gary or do static changes to toe put you back to where you were before you lowered?

As usual, it depends on how much you lower it, the recommended 340 mm at the rear is OK for bump steer with the standard arms, provided you do the camber adjustment on both arms (upper control arm and traction arm) in tandem. If you go much lower than 340 mm then you need to play with the length of both arms to achieve the desired camber without creating excessive bump steer. For example an R32 at 325 mm has more than 6 mm of toe change (bump steer) over the 75 mm of required suspension travel.

Static toe is corrected by the adjusting the length of the steering arms, that does nothing to correct the bump steer.

Cheers

Gary

[STATUS]

The only way to really adjust it correctley (as 99% of wheelaligners have no idea) is to do it yourself on a decent machine with the coil-overs removed, sit the car at its normal ride height (on jacks, with chocks under wheels to achieve correct ride height) and move the wheel through its bump and droop arc, watch the toe and adjust the arms to the postion which gives you the closest to std ride height readings.

Tedious to adjust but well worth it (f your need it in the first place), i hate bushes and would rather a little more harshness through some decent QA1 rose joints or similar. But i do agree that many cars i see have 100% wrongly setup arms and alignment.

Edited September 11, 2008 by URAS

[T04GTR]

cool always wonderd what the go was

[blitza]

so.... If I have lowered tein coilovers on 19" rims, how would i properly eliminate as much camber as possible??

I bought some 'camber' arms for my car, and upon attempting to install them myself, I saw that there was another (upper control arm? sorry I dont know what bit is what) piece that I would need adjusted as well to be able to adjust the camber of my car.

I hope that makes sense, but someone please help. What other part do i need to purchase to allow me to change the camber without effecting the toe (bump steer)? I know i will have to get a professional wheel alignment once everything is on and done