Your experience with polyurethane cradle bushings ?

[BmacIL]

Initially I wanted to install the set from Ford Motosport , but since they were discontinued and the prices are still relatively high for 4 pieces of aluminum, so I was able to find these , basically a Chinese copy of M-5872. Black ionized aluminium.

That is correct, Kelly said, that even the Delrin is cracking under heavy loads.



Indeed, Lock-outs are brilliant solution, with the possibility to going back to the original set-up. However, the weak point is still there. I believe BMR is planning to bring a new product on the market soon.

I'm not sure you're correctly analyzing it. By using the lockout, you're essentially taking the load off the bushings completely, thus you're unlikely to ever see the failure you're describing (which I understand is your worry).

Sponsored

 

[Martinnfb]

That would be 100 percent correct if we referring to the top load only. Yet we need to take to consideration also the lateral load . I mean this is very extreme point of view under normal driving conditions, however it is a part of the story that is largely neglected.
In other words , ( if I understand correctly) lock-outs are seated in the original bushing and the edge of the subframe. Bolts themselves are flexing under the load and I don't thing that the contact patch between the inserts and the subframe edge will/should pick up all the load.

Or , try to imagine , the function of the inserts in case if there is no rubber at all.

 

[BmacIL]

That would be 100 percent correct if we referring to the top load only. Yet we need to take to consideration also the lateral load . I mean this is very extreme point of view under normal driving conditions, however it is a part of the story that is largely neglected.
In other words , ( if I understand correctly) lock-outs are seated in the original bushing and the edge of the subframe. Bolts themselves are flexing under the load and I don't thing that the contact patch between the inserts and the subframe edge will/should pick up all the load.

Or , try to imagine , the function of the inserts in case if there is no rubber at all.

I know what you're getting at, and there's truth to it, but the lockouts do significantly stiffen the entire thing laterally/longitudinally as well, along with taking a good amount of load off the bushings. Not arguing that full replacement inserts won't do a better job, but I do think you're overstating the issues with the rubber once some form of robust subframe lockout is employed. My opinion, obviously, but it's based on lots of experience with vehicle development and testing. Rubber that's not being flexed/twisted/deformed will last for a very long time, assuming it's environmentally robust as is the type typically used here.

 

[Martinnfb]

I agree with that.

 

[BmacIL]

I agree with that.

Glad you're liking your setup! Getting the subframe under control and the deflection out of the suspension makes a world of difference in how this car drives and rides.

 

[Martinnfb]

Absolutely , I feel the comfort level raising as the rear is so much more predictable. A brand new car.
I’m in the car again and just noticed something interesting. It seems that the rear is slightly lifted, which makes sense due the thicker upper lip of the new bushings.

 

[hot rod]

If anybody is curious how it looks when the subframe cuts into the bushing.....here you go

 

[Alerch]

If anybody is curious how it looks when the subframe cuts into the bushing.....here you go

Bringing this up from the dead, all the pictures I see of the energy suspension cradle bushings do they have a metal lip around the flange as shown in the pitcures online can anyone confirm?

Sponsored