BMR Tech2

iTrader: (5)

What if you do hit a bump? Does the axle having more articulate mounts affect how a solid axle will react in relation to the ground? No. One side will come up, the other will stay down, and the contact patches will be limited to the edges of the tread. The articulation argument works on an IRS, but a solid axle will react the same over a bump no matter what suspension surrounds it. It only affects how the car above it reacts. When you have stiff springs, stiff valved shocks and swaybars, the car will remain as level to the rear end as possible.

Let me run one more thing by you guys who are still buying into the "no articulation is bad for cornering" theory. Have you ever seen a NASCAR rear suspension? It is a design that has been used for decades among all of the highest series cars. I think you may be quite surprised if you are not familiar with them;

[IMGhttp://image.circletrack.com/f/projectbuild/9402636+w799+h499+cr1+ar0/p141431_large%2Bchevrolet_monte_carlo_race_car%2Br ear_axle_view.jpg[/IMG]

01ssreda4

iTrader: (96)

I ran poly/poly BMR units for quite a while. They are noisier then stock in my opinion.... harsher over bumps is what I'm getting at. I recently sold them and bought some BMR double adjustable with poly/poly ends. I sold them because my rear end was not centered after making some pinion angle adjustments on my 12 bolt. For an average street car where harshness is a concern, stick with the stockers. If you are going to upgrade, skip my mistake and go straight to adjustables.

SparkyJJO

iTrader: (11)

But poly will strongly resist one side coming up and not the other, as that requires the axle to "twist" under the car. That twist is natural and should be allowed, not so strongly resisted. When you do that, you rock the whole car more than it should, which results in a rougher ride, and when encountering the bumps and unevenness in turns it essentially counters some of the force of the swaybars that are to keep the body level with the road.

And I'm not sure what that picture is supposed to prove. Last I checked nascar runs on perfectly smooth tracks with pretty wide and heavily banked turns. Totally not even close to cornering on the street. Go take that NASCAR on the road around some street cornering and see how well it handles that...

_JB_

iTrader: (33)

I've gone from stock, to rod/rod, to poly/poly for both PHB and LCA, and the only difference I've noticed was the rod/rod was noisy as hell. But this is all street comparisons.

BMR Tech2

iTrader: (5)

Nrakestr

iTrader: (1)

Great information. I've never been knowledgable about suspension components but I've already learned so much. Thanks for all your feedback!

TA_Freak

I vote for stock LCAs with Moog bushings for street. My own personal experience with poly on LCAs is I hated the instability of the car at highway speeds while turning. There is this one bend with a slight bump on the highway that I pass every day. I darn near jumped into the right lane hitting another car when I went over that bump while veering left (with the LCAs). I was able to regain stability and it felt safe again after installing my stockers with Moog rubber bushings.

RevGTO

iTrader: (12)

I had BMR poly/poly LCA's on my car for many years and replaced them with stockers w/Moog chasing down a squeak. Turned out the LCA's weren't the source of the squeak and I didn't notice any difference in harshness or handling.

Here's a good discussion of the articulation problem with poly, though:

http://www.crystalridge.net/cars/bushings.htm