LCA's, Tubular or box style?

[Roc87]

Wondering which I should go with. Right now my suspension is mostly stock, besides variable rate rear springs and air bags. I'm going to remove the front sway bar, install a ATR rear sway bar, and put in a line lock to keep the rear shoes a little cooler while heating the tires (My current best 60' is a 1.74 with a 2# Launch). I'm hoping for at least a low-mid 1.6x 60'. So, with that in mind, which style lower control arms should I get? Thanks!!!

 

[Pronto]

I love my HRs. Priced resonable an look great too.

 

[BJM]

The only difference you care about is the cross-sectional area of the arm. The one that is higher is stiffer. However, its the bushings that squish when you launch that dominate the total axial (along-the-length stiffness) of the arm. Stiffer bushings will make more difference than the type of arm.

On my car I put in the Camaro 1LE bushings in the lowers and boxed the stock arm myself.

 

[Lhorn]

What are the 1LE bushings made of? Have you noticed any difference with the boxed arms and stiffer bushing? And are the bushings noisey at all? Thanks

 

[BJM]

The 1LE bushings are made from a noticeably harder rubber than normal. But being rubber they won't squeak, they came factory installed by GM so you know they won't make any noises. I have had poly bushings in a car and they drove me nuts. The car feels firmer for sure. I did both at the same time so I cannot separate the two effects.

 

[ross87t]

I used BMR tubular LCAs.

They have grease fittings, and come with poly bushings.
The first pass w/ these, airbags, and MT et streets resulted in a 1.67 60'.

 

[Roc87]

Thanks for all the info! I went ahead with BMR style tubular lowers.

 

[Ormand]

BJM is right about the deflection. The bars are loaded in compression during a launch, but steel is so stiff relative to the bushings that the deflection of the bars (whichever bars) is negligible relative to the deflection of the bushings. The bars will shorten by maybe a thousandth of an inch, while the bushing will allow much, much more than that. When the car is leaning, or the axle is trying to tilt so one wheel can go over a bump, then the LCA has to twist. Under these conditions, the stiffness of the LCA has a much greater effect on suspension movement.