[radz28]

09.02.2022 - UPDATE

Everything seems to continue to be as good as I have expected. This isn't a thorough review for strip/track experience, but it's probably about as far as possible for the street. I've put probably at least 500-miles on the arms now.

Surprisingly - the additional noise isn't bad at all. Maybe some of that is the hot Summer months here, but, there's not, really, noise from the arms, themselves, I'd say. I would say they conduct more suspension/road noise, but they aren't adding much, if any, more through rattling or something. I have lubed-up the joints with some Amsoil metal-type lube/protectant, but don't know if I'm going to stay with that. I've read a post some of these petroleum-based lubes eat the pillow bushings, so I might degrease that stuff off and just install boots on all of them. I don't drive him in the rain or anything though, so I'm not yet sure.

Original OEM fasteners are still holding strong, and I've only had one come back a little loose, but it has remained torque-up since. I do have a complete set of new GM bolts for everything, but if I ever do the boots, I might use them, or just buy some high-grade reusable bolts instead, and call it good.

I don't know that I'd claim the car grips better, but, especially in hard turns, over irregular surfaces, it seems the rear is a lot better composed. In a straight line, under hard acceleration, the car seems to naturally go straighter than before. I'm still please with the purchase, and would do it again. I don't know if I'd say it necessary, and that everyone should do a form of control arms, but I feel better they're more robust, deflect less, and are just stronger. The rod ends did result in me upgrading the stab' bars, but I'd probably have done that anyways, and having some adjustability is nice.

I wouldn't sway anyone from this upgrade. I don't think I'd try to convince anyone they needed it, but it definitely helps my OCD, if anything else. I've traded a little NVH for the comfort of having a little more confidence in the car, and that's worth it for me.

[radz28]

09/11/2023 - UPDATE:

I'm probably the only dingus that this has mattered to, but I'll update anyways.

My OCD has been driving me crazy since starting this enterprise. Because of not doing research before my purchase, I did not understand that I'd be losing some measure of spring rate when moving to rod ends. I'm still not that positive on precisely how much spring rate I've lost, but, I did take a control arm, place it in a vice, and used a scale to see about how much pressure the rubber bushing applied at about 1-inch and about 4-inches of travel. The force I measured was about 7-lbs @ 1" and about 30-lbs @ 4". I was trying to get a spectrum from a little above ride height, to about full compression (I'll freely admit I hadn't tried to actually measure full compression, so I took a guess). I replaced 3-arms (per side), and each arm had a rubber bushing that was replaced by a rod end. So - even though I think I found a spring rate calculator for this, I didn't really take the time to calculate anything. BUT - I figured it couldn't be zero, so it was just driving me crazy.

In another moment of dingus, I thought if I slapped a bigger stab. bar on, it would make up for the difference, but that would only help in corners... Then - my OCD started going crazy because the front suspension balance might be off, so I, then, upgraded the front (aFe adjustables). I was still stuck with not compensating when going straight, and couldn't decide on risking more money and time on likely a fruitless effort, and, likely, possibly, losing some better weight transfer on the strip with softer spring rates in the rear (as a result of the rod ends). My OCD just couldn't accept throwing the OEM balance out of the window.

SO - I settled on a set of BMR springs, ONLY for the rear. The rate wasn't crazy-higher than OEM ZL1 coils, and even if it was, there were still 3-more rubber knuckle bushings I know I'll replace later, to compensate for (the lower control arm pivot looks like a spherical end), so I was future-proofing for my OCD. I was a little worried about ride height (as these are lowering springs), but more-so, losing ride quality. As it turns out, I am pleasantly surprised and happy with both. Before the coil install, my ride height was about 27.5-27.75", front and rear. It seems a little lower than stock from other information out there, but with the added weight of the 2650, and less spring rate from the rod-end-control-arms, it seemed logical. I've only put about 50-miles on the car, but it seems I haven't lost ANY height (it actually measures slightly higher than before). They might settle (or the rubber insulators) after a little more driving, but if I can keep it close to where it was, I'll be even more happy. The ride seems VERY comparable to OEM springs, too. It definitely wasn't too stiff at all. Driving over the same roads I have didn't yield much of any difference in ride quality and everything is about as good as I could have hoped for.

So - for anyone trying to make up for spring rate loss as a result of control arm rod-ends, these BMR (lowering) springs, with higher rates them OEM, seem to be okay. I recognize they may not be as optimal as YYZ and what not, but I didn't need and want a whole set, nor did I want to lower the car. So far - these seem to fit the bill great, and when I get around to replacing the last of the rubber bushings in the knuckles, I'll have some spring rate "in reserve". I wouldn't say I recommend this, but for my purposes: I am very happy and my OCD, for this aspect, is at rest.