DIff bush upgrade ?

[digger]

What's the best rubber diff bush to use in a standard e30 MC diff cover and not get NVH transferred into the body but have a little bit more stiffness and better longevity in an upgrade power level?

OE p/n seems to be 33171135242

I've seen this mentioned apparently from Z3, is it an actual upgrade?

33172228425

[Staszek]

What's the best rubber diff bush to use in a standard e30 MC diff cover and not get NVH transferred into the body but have a little bit more stiffness and better longevity in an upgrade power level?

OE p/n seems to be 33171135242

I've seen this mentioned apparently from Z3, is it an actual upgrade?

33172228425

The Z3 one is an upgrade and when you see them side by side with the original it is quite a bit stiffer. Its also way more expensive. There are poly ones that are not rough. Garagistic offers some different options.

https://www.garagistic.com/collections/e30-performance-parts/products/poly-differential-bushing-e30-e36-318ti-z3

[moatilliatta]

I've been using vibra Technics on street cars.

https://www.vibra-technics.com/bmw/z3/641/BMW370M/diff_mount_bush_e30_z3_and_e36_compact

https://www.ebay.com/itm/BMW370M-Vib...-/302396625587

[digger]

I've been using vibra Technics on street cars.

https://www.vibra-technics.com/bmw/z3/641/BMW370M/diff_mount_bush_e30_z3_and_e36_compact

https://www.ebay.com/itm/BMW370M-Vib...-/302396625587

Are they actually OEM in feel in terms of NVH? or is that just what the marketing material says?

[digger]

The Z3 one is an upgrade and when you see them side by side with the original it is quite a bit stiffer. Its also way more expensive. There are poly ones that are not rough. Garagistic offers some different options.

https://www.garagistic.com/collectio...0-e36-318ti-z3

Ahh, yes $220 vs $80

[Victell]

Is a diff bushing upgrade only for increased power or does it also affect handling?

[reelizmpro]

I got a 2 pc powerflex street poly bushing that comes with large washers for like $45 or so. Easy installation since it's 2 pc and relatively cheap.

[moatilliatta]

Are they actually OEM in feel in terms of NVH? or is that just what the marketing material says?

I think its the closest you can get without going poly. I wouldn't get anything garagistic.:(

Id say its louder, if you're diff is loud you may notice it more. Check the ebay link, they are cheaper.

But not as loud as poly, If concerned, id stick an OEM one in, I think sub frame bushings may transmit more sound.

Keep it rubber! https://www.turnermotorsport.com/p-3...rack-e30-pair/

[digger]

I think its the closest you can get without going poly. I wouldn't get anything garagistic.:(

Id say its louder, if you're diff is loud you may notice it more. Check the ebay link, they are cheaper.

But not as loud as poly, If concerned, id stick an OEM one in, I think sub frame bushings may transmit more sound.

Keep it rubber! https://www.turnermotorsport.com/p-3...rack-e30-pair/

its a "rebuilt" diff so should be fairly quiet but the reason i got this was the old was was a whiny *******ch.....i think OE Z3 may be the happy medium

[dadsbmw]

I have poly diff bushings and notice basically no increase in NVH

[nando]

stock Z3M.

poly in my experience end up distorting too much and offers little benefit over stock if it's soft enough to not be annoying.

[digger]

i think this is the order of stiffness of the bushes

Solid E30: 33171134802
Z3M: 33172228425
Stock E30: 33171135242

the solid E30 seems stiffer than Z3M but it aint any cheaper

[moatilliatta]

Solid E30 is IX?

[digger]

Solid E30 is IX?

Seems to be that way

[nando]

yeah, I can confirm my stock rear bushing was solid. Also supposedly it's offset for the ix ride height.