Are Current OE Rear Subframe Bushings Improved?

[oceansize]

From personal experience, the CMP bushings bring the subframe up more than what plates push it down. Not sure how much more, but with stock everything (except CMP subframe bushings), I couldn't get my rear camber to go past -0.5 deg.

If you weren't lowered then this is the expected outcome. From CMP:

If the car is still at factory ride height, the resulting change in camber geometry limits negative camber adjustment to less than ideal for sporty driving. We'd like to imagine that if you've purchased these subframe bushes this likely isn't your first suspension modification however, if your car is still are factory ride height, adjustable camber arms are required to dial in more negative camber.

[heinzboehmer]

Wouldn't raising the subframe put it back in the position it was from the factory?

If the reinforcement plates push the subframe down by the thickness of the plates, and the bushings raise it back up to correct for the plates...

From personal experience, the CMP bushings bring the subframe up more than what plates push it down. Not sure how much more, but with stock everything (except CMP subframe bushings), I couldn't get my rear camber to go past -0.5 deg.

[r4dr]

Raised refers to the subframe going up higher (closer to body), back to stock height even though you have plates.

Doing this puts you back in stock camber adjustment range (with stock chopsticks)

This is what I've been trying to say... feel like I'm taking crazy pills over here.

[oceansize]

One more thing I forgot to ask about the solid raising bushings (slightly raising the subframe), is there any concern with the driveshaft angle relative to the diff? Hopefully, that will not impact the service life of the driveshaft, CSB, diff or diff bushings.

Just ask Cayn AussieE46M3 , he is really good dude within the community and always responds with detailed answers. Obioban just installed the CMP subframe bushings on his car and we all know he isn't one to put something wonky on his vehicles.

[old///MFanatic]

Raised refers to the subframe going up higher (closer to body), back to stock height even though you have plates.
Doing this puts you back in stock camber adjustment range (with stock chopsticks)

Oh well if they machine them shorter and have less material on top that would certainly make sense. Geez it’s so basic I’m embarrassed didn’t catch on. I did wonder why someone would want it lifted/raised. If listed as being made shorter then would have known.

But didn’t Slideways show photos in post #20 how the recessed cup at the top on solid mounts where it would connect to the hex of the stud was no longer there in latest production for “raised”? And even appear to show a raised protruding aluminum center? In his photo the back two show their tops. These don’t have the recessed section for where (front) makes contact to the subframe stud hex nut.
*edit* Suppose they can still make top hat area shorter and protruding center shorter than original unit height.

[Tbonem3]

Raised refers to the subframe going up higher (closer to body), back to stock height even though you have plates.

Doing this puts you back in stock camber adjustment range (with stock chopsticks)

[r4dr]

Plates add material. Like if you added washers on top of the raised bushings. I don’t see how that would make it even out.
Diff carrier would be lower from the body and diff driveshaft geometry makes sense should be altered some.

Yeah, but wouldn't the plates add material in the opposite direction that the bushings would be raising the subframe? I don't think "raised" subframe bushings push the subframe farther down?

[old///MFanatic]

Wouldn't raising the subframe put it back in the position it was from the factory?
If the reinforcement plates push the subframe down by the thickness of the plates, and the bushings raise it back up to correct for the plates...

Plates add material. Like if you added washers on top of the raised bushings. I don’t see how that would make it even out.
Diff carrier would be lower from the body and diff driveshaft geometry makes sense should be altered some.

[Slideways]

Wouldn't raising the subframe put it back in the position it was from the factory?

If the reinforcement plates push the subframe down by the thickness of the plates, and the bushings raise it back up to correct for the plates...

Yeah, but the CMP document also stated something about correcting the suspension geometry for lowering the car.

[r4dr]

One more thing I forgot to ask about the solid raising bushings (slightly raising the subframe), is there any concern with the driveshaft angle relative to the diff? Hopefully, that will not impact the service life of the driveshaft, CSB, diff or diff bushings.

Wouldn't raising the subframe put it back in the position it was from the factory?

If the reinforcement plates push the subframe down by the thickness of the plates, and the bushings raise it back up to correct for the plates...

[Slideways]

One more thing I forgot to ask about the solid raising bushings (slightly raising the subframe), is there any concern with the driveshaft angle relative to the diff? Hopefully, that will not impact the service life of the driveshaft, CSB, diff or diff bushings.

[Slideways]

CMP replied saying that both older and newer style bushings only contact the hex portion on the front subframe studs. The redesign helped with manufacturing costs and made the bushings 15% lighter in weight.

[old///MFanatic]

^ If I read the CMP website correctly they redesigned their solid bushings to raise them.

If the car these bushings are fitted to has been lowered ~13mm, (1/2”) or more, you’ll find that the change in rear camber from both is equally opposite and you'll remain roughly in the same range of adjustment as before. To be clear, the need for adjustable camber arms when fitting these bushes only exists when the car is still at stock ride height.

[Epsilon]

For anyone who has installed solid subframe bushings, are the two front bushings supposed to contact the hex on the subframe mounting stud or the RACP sheet metal?

CMP changed the design slightly to match other solid bushings which seem to contact just the hex portion of the subframe stud. The previous CMP bushings had a machined portion where the hex slotted in:

Very nice observation! It would be interesting to find out from CMP why the design change.

[Ianb]

When I made mine, rightly or wrongly I made them to touch both the hex spacer and the bodywork (reinforcement plate) so the bush had a recess in the top exactly the depth of the hex, thinking best to spread the load over the reinforcement plate and also the stud through to the upper reinforcing/brace.