SPL Multilink Arms & Nismo Power Brace

The plan is to start posting a series of Overviews on the more important parts I’ve amassed thus far, with a few random bits in between. Let’s start with the SPL Pro suspension arms and Nismo power brace. I bought these directly from SPLParts.

While deciding which arms to go with, I discovered there were quite a few options out there, ranging from crude and basic overseas variations to much higher end products. For this car, my focus will be on the suspension and drivetrain, which is why I didn’t have to debate too long before siding with SPL. Although more expensive than competitors and comparable offerings, I think the higher premium is justified. By specs and features, nothing else even comes close.

Here’s a tension rod.

You can’t really tell in the pictures, but in person, it is BEEFY. The tension rods are CNC machined from billet aluminum and then anodized black.

The rest of the arms, like the Rear Upper Control Arm shown below, have DOM mandrel bent tubing. These are all made in the USA, and the materials are sourced from American suppliers as well.

Everything is tig welded and then powdercoated with a urethane based black. I initially wanted to get these arms in chrome (which is now being discontinued) for the bling factor, but was informed of its disadvantage; by effect of the chroming process, hydrogen embrittlement of the metal occurs. Powdercoat it is, function trumps form.

Aside from sheer quality and construction, SPL is innovative in their designing and engineering. Some of the arms like the RUCAs have an upward curve to them in order to accommodate clearance for lowered cars. But the bearings and adjusters are probably the highlight.

SPL had previously used QA1 spherical bearings, but now use a version customized to their specs and utilizes a carbon-matrix insert for smoother spinning and durability. Contrastingly, cheap suspension arms typically have very weak bearings, which are prone to failure and even breaking under stress.

A system SPL termed the hybrid adjuster is used rather than conventional jam nuts. By tightening the aluminum clamp, it allows for independent locking and lets the bearing maintain a straight position, rather than being rotated and cause binding. As an added touch, I unscrewed all the threaded parts on the arms and applied anti-seize before reassembling.

Now, moving onto the Nismo power brace. I grabbed this at the same time as the arms. It replaces the stock tension rod brackets and features a cross brace for added rigidity.

There is further bracing via welded plates: