These arms were the first mod I threw at my sedan. I wore the OE tires into cones. I've attached a photo of the left rear tire. Outside is to the left.

I am a firm believer in the right tool for the job, and for suspension I think camber adjustment is mandatory. I looked at the various arms offered and thought the SPL arms showed the best engineering so I purchased a set from ImportPartsPro along with a set of SPC rear camber arms in early 2015.

I didn't have access to my tools or a second vehicle so I made an appointment with a local race shop that performed work on my Miata. They installed the parts and performed an alignment in about two hours. I asked for and got -2° camber on all four corners.

The best thing I can say about the SPL arms is that they are "invisible". No noise, no loosening, they just quietly perform their job. Yes, they were the most expensive but I think I got what I paid for. Future aligners will appreciate that both caster and camber are adjustable.

 

Thanks for the review. Great to hear the SPL's are quiet. I was on the fence with getting these because I was worried the spherical bearing design would be noisy. So I was leaning towards getting the SPC's instead.

Were you able to increase your caster as well? If so, by how much and did steering stability, especially at higher speeds, improve with the additional caster?

 

I don't know about the caster. I haven't had the car over a hundred MPH so can't speak towards a change in stability.

 

Lol. Do you need to be going over a 100mph to notice a difference in stability? I was thinking more like highway cruising; 65-75 mph.

 

The biggest thing I noticed was the car was much more eager to turn, what with the extra camber and toe-in reduced from 10mm to 5mm. The car's tendency to drive straight was less with the reduced toe. But I don't attribute any change to caster.