[Eric SS]

Debating between these 2 options as the price seems to be comparable. The BMR spherical bearings for the front radius rods and lower control arms and for the rear trailing arms and control arms seem pretty cool. The GM ZL1 1LE Spec handling upgrade kit I think takes care of the same bushings. They won’t be as stiff but do the BMR spherical bearings do ok on the street as far as longevity is concerned? Are the ZL1 1LE components ACTUALLY different and stiffer or is it just the bushings that make the rods and arms stiffer? Or is there material actually added to the trailing links? Are the ball joints different?


ZL1 1LE kit: http://www.gmperformancemotor.com/parts/84352119.html

BMR items:
rear: http://m.bmrsuspension.com/?page=pro...=121&catid=449
And front: http://m.bmrsuspension.com/?page=pro...=121&catid=450

Or third option. Use the BMR trailing arms and upper control arms and their spherical bushings in the front?

Any other options? Front tire wear especially needs help. Killing the inner and outer edges with tons of center tread left. Thanks all

[kropscamaro16]

since you already have bmr i would go bmr but its up to you lol pricing wise how different is it?

[Eric SS]

Originally Posted by kropscamaro16

since you already have bmr i would go bmr but its up to you lol pricing wise how different is it?

If you just go with the spherical bearings from BMR vs the ZL1LE kit, it’s very comparable if my math is correct.

EDIT: the BMR suspension I currently have are their springs, adj sway bars and end links, toe rods, and strut tower bar.

[kropscamaro16]

i would just keep it all bmr and im sure they will give you a good deal if you keep it all bmr

[Eric SS]

Originally Posted by kropscamaro16

i would just keep it all bmr and im sure they will give you a good deal if you keep it all bmr

I almost forgot, I do have their stickers on my car so that alone adds probably .2g.

[BMR Tech]

Originally Posted by Eric SS

Debating between these 2 options as the price seems to be comparable. The BMR spherical bearings for the front radius rods and lower control arms and for the rear trailing arms and control arms seem pretty cool. The GM ZL1 1LE Spec handling upgrade kit I think takes care of the same bushings. They won’t be as stiff but do the BMR spherical bearings do ok on the street as far as longevity is concerned? Are the ZL1 1LE components ACTUALLY different and stiffer or is it just the bushings that make the rods and arms stiffer? Or is there material actually added to the trailing links? Are the ball joints different?


ZL1 1LE kit: http://www.gmperformancemotor.com/parts/84352119.html

BMR items:
rear: http://m.bmrsuspension.com/?page=pro...=121&catid=449
And front: http://m.bmrsuspension.com/?page=pro...=121&catid=450

Or third option. Use the BMR trailing arms and upper control arms and their spherical bushings in the front?

Any other options? Front tire wear especially needs help. Killing the inner and outer edges with tons of center tread left. Thanks all

The bearing upgrade will definitely increase the consistency of the car by eliminating the deflection of the bushings that the replace, but there will be increase in NVH. Are you still running all of the factory arms? I believe the ZL1/1LE kit has higher durometer rubber bushings but they are still rubber bushings. PM me or call me and I will see what we can package together for you.

[Eric SS]

Originally Posted by BMR Tech

The bearing upgrade will definitely increase the consistency of the car by eliminating the deflection of the bushings that the replace, but there will be increase in NVH. Are you still running all of the factory arms? I believe the ZL1/1LE kit has higher durometer rubber bushings but they are still rubber bushings. PM me or call me and I will see what we can package together for you.

Thanks Frank. I don’t really care about NVH since I don’t daily the car. All the arms are still factory but the plan is to change hose out to either your arms or the ZL1LE depending on what I find out about them. I’ll definitely reach out

[BMR Tech]

Originally Posted by Eric SS

Thanks Frank. I don’t really care about NVH since I don’t daily the car. All the arms are still factory but the plan is to change hose out to either your arms or the ZL1LE depending on what I find out about them. I’ll definitely reach out

10-4 Sounds good Eric!

[Ryephile]

If you're building a track-only car and truly don't care about street manners, then going full spherical bearing is the best solution for precise wheel control. That means eliminating the rubber in the strut mounts, front control links, every bushing in the rear end, including subframe. It looks like BMR offers enough line items to pull it off but I can't see how they retain the rear lower control arm alignment eccentric. Hopefully they can clear that up.

Also know that spherical bearings are fantastic in the beginning, but they also wear our and become loose over time. That means mandatory replacement much more often than rubber bushings. As long as you budget that into your tracking programme, you'll be good.

I definitely do not recommend polyurethane. Having been down that road, it's an awful bushing choice for cars in most applications, definitely ones with complicated articulation paths like our virtual pivot front strut and rear multi-link suspensions. Poly really can only work on straight-up axial applications, ditto with delrin. A solid rubber bushings is infinitely preferred over poly in pretty much every scenario.


It appears the ZL1 1LE "arms and bushings" kit ends up being a mix of mostly rubber bushings and two spherical bearings, to be verified. This might give a good mix of compliance and control, and seeing the cir-clipped boots on the bearings in the GM kit means they went the extra step to weather-resist the bearings so they'll last longer. Weather wears out spherical bearings much quicker than clean & dry track use. Get some salt spray in an unprotected spherical and they're F'ed in short order.