Z28 Radius Rod bushings or BMR

[dma05]

I just purchased both Z28 front lower control arms for my 2011 SS. I have the BMR bushings here as well and was wondering if I should knock out the bushings in the Z28 control arms for the BMR.


thanks for any info

[hesster]

I did not use a Z28 Arm, and went with the stock Arm and replaced the spongey stock bushing. Using the BMR piece versus the Z28 depends on the durometer of the 2 bushings, if BMR is "stiffer" than Z28 maybe go with it. I remember pressing the stock one out was a real chore on my 12 ton press - it even bent the press rod slightly before it let loose and came out. Installing the BMR piece is a breeze however.
"Front LCA Front - Bushing (the Arm with the Large Bushing) – this is easily assembled into the arm, and a vice or hammer can be used. It is a (3) piece bushing with a different center bushing durometer, press or hammer the center in first, then the outers, then the inner sleeve. Stuff it into the Sub Frame – it is a real tight fit, and I used a screwdriver to align the holes to the frame. Loose install the bolt and nut for now, do not tighten yet, as the bushing will need to be “Timed”. This is a TTA Bolt, and ideally should be replaced."

[dma05]

Originally Posted by hesster

I did not use a Z28 Arm, and went with the stock Arm and replaced the spongey stock bushing. Using the BMR piece versus the Z28 depends on the durometer of the 2 bushings, if BMR is "stiffer" than Z28 maybe go with it. I remember pressing the stock one out was a real chore on my 12 ton press - it even bent the press rod slightly before it let loose and came out. Installing the BMR piece is a breeze however.
"Front LCA Front - Bushing (the Arm with the Large Bushing) – this is easily assembled into the arm, and a vice or hammer can be used. It is a (3) piece bushing with a different center bushing durometer, press or hammer the center in first, then the outers, then the inner sleeve. Stuff it into the Sub Frame – it is a real tight fit, and I used a screwdriver to align the holes to the frame. Loose install the bolt and nut for now, do not tighten yet, as the bushing will need to be “Timed”. This is a TTA Bolt, and ideally should be replaced."

Thanks for all the info! This will definitely help if I decide to install the BMR bushings in the Z28 arms. Just not sure if anyone knows the difference or if one is better than the other. This car isn't my DD at all, just driven about 1-2 times a month.


thanks

[gtstorey]

No reason to install the BMR bushing in the Z28 arm that I'm aware of over just installing it in the stock arm. The arms are the same between the SS and Z28. The bushings are what is different. I've only ran the Z28 so can't compare to the BMR bushings.

[Joe.G]

Everything I have read is the Stock front Camaro LCA bushings are a good piece and there is no need to replace those. I have replaced all int he rear but have only done the Radius inserts and in the front Besides sways.

[hesster]

Part of the "Fun" in your build is sorting thru opinions on what is "Best", and what, or what not to do. The decision for me to replace the stock bushing was easy by comparing the Original Stock Bushing with the BMR piece. Again, if the Z28 bushing is as good as or better than the BMR piece, then maybe keep it and move on

[hammdo]

I did 6th Gen aluminum radius rods and updated those to the BMR bushings:

https://www.camaro5.com/forums/showt...85577&page=174

More Castor!

For the current Z version, they're good as they are...

-Don

[cdb95z28]

Originally Posted by dma05

I just purchased both Z28 front lower control arms for my 2011 SS. I have the BMR bushings here as well and was wondering if I should knock out the bushings in the Z28 control arms for the BMR.


thanks for any info

No. Poly here is a major step backwards.

In fact poly anywhere except at an anti-roll bar is a step backwards for cornering perfection.

[Joe.G]

Cdb, that is what I have heard many times and read from people well versed in this stuff that in the front on these cars the factory is the way to go/stay which is the only reason I have not changed them.

[WVracer]

Originally Posted by cdb95z28

No. Poly here is a major step backwards.

In fact poly anywhere except at an anti-roll bar is a step backwards for cornering perfection.

Can you elaborate on that at all? From what I've been reading it helps a lot with steering and brake feel. I'm thinking of doing these myself so I would like to know if these or a complete arm replacement is worth it.

[KillboyPowerhead]

For what it's worth, JusticePete said that the bushing in question (front lower control arm) was very well made from the factory and wouldn't need to be replaced unless building a dedicated track car. The Z28 further improves on the bushing. Unless you have a full blown track car I'd say you'd probably do just fine with the Z28, or even non-Z28 factory bushing.

[Joe.G]

The Radius insert or bushings are recommend but the Control Arm bushing is supposedly a great OEM piece.

[gtstorey]

Originally Posted by WVracer

Can you elaborate on that at all? From what I've been reading it helps a lot with steering and brake feel. I'm thinking of doing these myself so I would like to know if these or a complete arm replacement is worth it.

Poly does good when in pure rotation like a sway bar and less well when there is movement that isn't pure rotational movement. A lot of our suspension has movement in more than one direction and the poly doesn't move as freely as the suspension needs to since it isn't only trying to rotate the arms. A lot of the Z28 parts have a rubber coated monoball/spherical bearing that allow rotation in more than one axis.

At some point the poly may offer more feel since it will be stiffer, but will also make the car act like it is sprung stiffer. Then the non rotational loads will start to wear the bushing and the suspension will feel loose again.

That's the discussion I've seen put out on forums and it makes sence to me, but how much of this is actually measurable, I don't know. At some point, OEM parts will disappear (we may be already getting to that point for Z28 parts) and the poly will be the only option for wore out suspension parts. That's sort of where my C4 Corvette is without spending major money for semi-custom heim joint suspenion.

[cdb95z28]

Originally Posted by Joe.G

Cdb, that is what I have heard many times and read from people well versed in this stuff that in the front on these cars the factory is the way to go/stay which is the only reason I have not changed them.

The Z/28 radius rod is pretty much the best arm/joint as far as a simple remove and replace. One option is to do the Gen6 aluminum radius rod with a BMR spherical joint just as Hammdo did. I did this on my '14 SS 1LE and I felt it was a positive mod. Before I traded that car, I demodded and that arm will now go into my new '22 SS 1LE.

Originally Posted by WVracer

Can you elaborate on that at all? From what I've been reading it helps a lot with steering and brake feel. I'm thinking of doing these myself so I would like to know if these or a complete arm replacement is worth it.

I will say that the Z/28 radius rod is nothing more than the normal Camaro radius rod but with a very stiff (probably Delrin) insert. This insert is visible in the joint as it is an off white color. My experience with this type of insert is that you will feel it more under heavy braking. It minimizes compression of the joint under the heavy braking. It will feel like the chassis responds to the heavy braking in a more direct, positive way.

Originally Posted by KillboyPowerhead

For what it's worth, JusticePete said that the bushing in question (front lower control arm) was very well made from the factory and wouldn't need to be replaced unless building a dedicated track car. The Z28 further improves on the bushing. Unless you have a full blown track car I'd say you'd probably do just fine with the Z28, or even non-Z28 factory bushing.

I concur.

Originally Posted by Joe.G

The Radius insert or bushings are recommend but the Control Arm bushing is supposedly a great OEM piece.

I took a Z/28 LCA and put it in a press where I added the same type of lateral stress the bushing would receive in a turn. Surprisingly the bushing is quite robust. It's not much to look at. But it works.

Originally Posted by gtstorey

Poly does good when in pure rotation like a sway bar and less well when there is movement that isn't pure rotational movement. A lot of our suspension has movement in more than one direction and the poly doesn't move as freely as the suspension needs to since it isn't only trying to rotate the arms. A lot of the Z28 parts have a rubber coated monoball/spherical bearing that allow rotation in more than one axis.


At some point the poly may offer more feel since it will be stiffer, but will also make the car act like it is sprung stiffer. Then the non rotational loads will start to wear the bushing and the suspension will feel loose again.

That's the discussion I've seen put out on forums and it makes sence to me, but how much of this is actually measurable, I don't know. At some point, OEM parts will disappear (we may be already getting to that point for Z28 parts) and the poly will be the only option for wore out suspension parts. That's sort of where my C4 Corvette is without spending major money for semi-custom heim joint suspenion.

Exactly! Poly tends to deform over time. It makes noise. It needs lubrication. It creates bind. We don't want any bind. I see guys remove the outstanding "rose joint" type of spherical joint on OE rear arms and I shake my head. Depending on the model iteration, some Camaros have alot of rose joints in the rear. This is a great thing. They are the perfect joint for zero bind. Zero bind is what we want for excellent handling. Let the springs and anti-roll bars do their thing when it comes to roll/pitch stiffness. But maybe some guys don't care about excellent handling, responsiveness and feedback, so what ever makes you happy. Sometimes the OE arm/mount is the best. The Z/28 radius rod is hard to beat.