Poly bushings for RACP/Diff.

[BMWahba]

Finished my complete rear end a few months ago and went solid subframe from CMP, oe everywhere else, and my lower arca is this ground control with bearing which is really nice and heavy duty. I really like this setup and I came from poly in my subframe.

I have been toying with the idea of going solid bushings in the outer upper control arm bushing and lower outer control arm bushings. Supposedly, these have a low impact on NVH. But I’m unsure, lol. Don’t want to have to do these twice.

If anyone has run this setup please chime in!

[Tbonem3]

AKG 90a/95a Poly bushed subframe and diff for 4.5 years now been great! Love the crispness. Only NVH "penalty" is some diff whine at freeway speeds that I cut in half with closed cell foam sheet under the rear bench.

[Dash1]

I have TMS solid subframe bushings and 95A poly diff bushings as the shop doing the work was very adamant of the NVH increase. Or lack of NVH increase I should say. It does whine, but it's negligible I have to admit.

[Dash1]

AKG 90a/95a Poly bushed subframe and diff for 4.5 years now been great! Love the crispness. Only NVH "penalty" is some diff whine at freeway speeds that I cut in half with closed cell foam sheet under the rear bench.

Did you go to Racewerkz for the work? That's exactly what they wanted to put into my car. I opted for solid subframe bushings though

[jixer77]

I have AKG poly on both subframe and diff and the NVH is a bit higher than stock. Car is solid and I don’t mind the extra NVH since it isn’t my daily.

I hear a lot more of clunking and diff whirring noise.

I would go back to OEM for next time.


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[Tbonem3]

Did you go to Racewerkz for the work? That's exactly what they wanted to put into my car. I opted for solid subframe bushings though

Correct.

[enjoy_m3]

I went from all stock to AKG 90A subframe bushings/ RTABS and 80A rear differential bushings, oem front diff bushing. This setup was really street friendly. Slight NVH from 80a differenital bushings, but not annoying. It was more responsive. After finding failed spotwelds, I realized I need to reinforce the topside so I installed a vincebar and went AKG Solid Subframe bushings and stock differential bushings. I also had the trunk panels and joining panels around it and under the seat stitch welded for rigidity. The rear end is much more rigid (similar feeling to adding a roll cage). There's isn't actually noise/vibration, maybe a little harshness if you're picky but it's more a solid feeling from the rear end. It's really not any worse from the poly setup I had before. I'm very happy with the setup now. If you were in SoCal, your welcome to ride in the car to get a feel.