To be fair, the broken SPC arm was under track condition with a very fast driver and rather sticky tires. A bigger complaint among track guys is that the rubber bushings don't stand up to track torture.

On a street car, SPC should be fine. But if you can spend the dough, and/or eventually want the benefit of having the solid spherical bushings, then just save up and bite the bullet all at once. Every arm change requires an alignment, so pick one and just stick to it.

I'm a proponent of more-than-enough however. I have front and rear SPL arms. Here's my Build thread for some free advertising for SPL, I let my coilovers sit 6 months in my living room to wait for the SPL front arms
cv129's slow build - Nissan 370Z Forum

Bushing flex example
LG Motorsports MonoBall Control Arm Packages 2 - YouTube

 

Also the 2 documented SPC front arms that broke, were due to cars being too low, and the arms impacting the inner fender.

 

As I thought. I still am not aware of any of them failing from normal regular street use on our platform.

 

Gs are fine from the factory as a daily, you don't need any after-market parts. If you start messing with the suspension then you are likely to also enjoy spirited driving and non-oem parts should be engineered to handle the extra stress. There is no reason to get front or rear arms if you aren't lowered. It's would disingenuous for an after-market company to claim that their parts aren't made to handle non-oem specs.

 

Thanks for your build link. Killer Z you've put together and really concentrated your build in all the right places. Those look like some top shelf coilovers and w/ the beefed up upper shock mounts along w/ the SPL parts that should be one well supported suspension. Bet that Z puts a big grin on your face

 

I don't think SPC claims racing or high performance applications.
They just make alignments possible!!

SPL, however, does.

 

That was a good call, to reinforce the shock towers. They were only originally designed to handle the damper.

 

Thx for the kind words guys. Seen plenty of guys running true type rears without reinforcement without any issue, but I don't want to test it.

Oh and if anybody is wondering about NVH...3 pairs of SPL arms, coilovers with solid top mount (eliminated stock rubber top), all of them installed together onto a car with very little sound deadening to start with, I did notice louder road noise especially the higher frequencies ones, but it's nothing outrageous (I say about 10% increase by my subjective ears). On a G, with much more plush interior and sound deadening, one shouldn't notice increased noise (or should be very minimal)

 

I now have the SPL front arms, along with the SPL rear camber and traction arms, along with Whiteline diff bushings.NVH has increased, but mostly tire noise, nothing a Bose playing Hair Nation cant cover!!