To polybush or not to polybush, that is the question?

[twenty]

E30 cabrio. Street car. Currently on OE bushes all around. Since car will have a full underside refresh, opportunity to rethink bushing.
Contemplating switching bushings to Powerflex Purple (or maybe even SuperPro/AKG) options are:

- Polybush all around
- Polybush all around apart from rear training arms
- Polybush all around apart from rear trailing arms and diff mount
- Stick to OE

[flybynite]

For me - Stick to OE. How it is meant to be and no squeaks.

Being a cab I don't think you would see the benefit and being street driven I don't think you need it, only downsides IMHO.

[rix313]

They do make the ride noticably harsher. There are heritage options to stay away from the garish purple and yellow. Not sure why you would avoid doing the rear trailing arms though? If anything if you wanted to go polybush and retain some compliance at the rear end you'd want to use standard rear beam bushes.

[twenty]

Seems like it’s general consensus that for RTA rubber is better because of lateral movement?

[DanThe]

Trailing arms only need to go up and down, as per the E30Zone tried and tested recipies the only place worth fitting poly for a road car is the trailing arms and the ARB bushes, OE rubber everywhere else

[twenty]

Trailing arms only need to go up and down, as per the E30Zone tried and tested recipies the only place worth fitting poly for a road car is the trailing arms and the ARB bushes, OE rubber everywhere else

Excellent. I’ll take this. For ARB, both front and rears?

Does zone recommend Powerflex or something else?

[DanThe]

In my experience powerflex are not the best, they are designed to be DIY/easy to fit, so you get split bushes where a one piece bush is usually used. I prefer Superpro, they have a nice knurled style finish on the inside which helps retain grease and stops the creaks/squeaks

[twenty]

In my experience powerflex are not the best, they are designed to be DIY/easy to fit, so you get split bushes where a one piece bush is usually used. I prefer Superpro, they have a nice knurled style finish on the inside which helps retain grease and stops the creaks/squeaks

Cheers. Did have SuperPro and AKG on my options. Sounds like SuperPro it is.

[BenHar]

Fit OEM M3 off set front wishbone bushes to improve steering feel.

Ben

[twenty]

Fit OEM M3 off set front wishbone bushes to improve steering feel.

Ben

Thanks. Is it part no 8 in http://bmwfans.info/parts-catalog/E30-2 ... _wishbone/?

[twenty]

Fit OEM M3 off set front wishbone bushes to improve steering feel.

Ben

Thanks. Is it part no 8 in http://bmwfans.info/parts-catalog/E30-2 ... _wishbone/?

To answer my own question - that's the part. Also found this https://www.e30zone.net/e30wiki/index.php/Bushes.
I might as well fit the Mondeo drop links I guess while at it

[twenty]

On a side note... the recommended diff bush from Z3 is now only £222. The page lists it at £21.34 hahaha.

[flybynite]

To answer my own question - that's the part.

You used to be able to get Lemforder ones to save paying BMW prices, haven't checked recently but I know they stopped doing subframe bushes

On a side note... the recommended diff bush from Z3 is now only £222. The page lists it at £21.34 hahaha.

You need to look at the price of the diff cover that goes with it glad I bought mine when I did

[twenty]

Fit OEM M3 off set front wishbone bushes to improve steering feel.

Ben

On this, I found the very informative article here https://www.rtsauto.com/e30-control-arm ... -bushings/.
Instead of the M3, I settled for the E36 M3 solid Rubber centered bushes, part no 31129069035. Let's hope that works out!

[BenHar]

They will give a slightly harsher ride than the E30 M3 bushes.

Ben

[twenty]

They will give a slightly harsher ride than the E30 M3 bushes.

Ben

Oh well! But hoping that at least they won’t change the wheel offset.

[DanThe]

If you intend on upgrading the steering rack with an E36/Z3/E46 then you will want to be using the offset E30 M3 bushes

[twenty]

If you intend on upgrading the steering rack with an E36/Z3/E46 then you will want to be using the offset E30 M3 bushes

I’ve decided to stick with stock for now. It’s a cab not fast and furious driver haha. The rack will be fully disassembled and refurbished.

I’d love it though if you made standard power steering lines like you do for the E46 conversion.

Thanks.

[reggid]

In my experience powerflex are not the best, they are designed to be DIY/easy to fit, so you get split bushes where a one piece bush is usually used. I prefer Superpro, they have a nice knurled style finish on the inside which helps retain grease and stops the creaks/squeaks

I'm currently planning a refresh of the rear bushes so I'm interested in which bushes are you referring to? Both the subframe and trailing arm from both Powerflex and Superpro are split (2 piece) so its not apparent why this would favour one or the other . If any anything on the subframe bush the main bush is single piece with the PF but another cup whereas the superpro is split half way up

Both brands offer adjustable trailing arm bushes though i don't know if this is better than converting to the eccentric bolt setup with concentric bush to correct known alignment issues

The Powerflex trailing arm bushes are also knurled, though maybe at one point they weren't not sure on subframe. But the trick with all poly is PTFE tape to stop squeaks and i needed to do this on the sway bar front bushes

To me it seems six of one or half a dozen of the other with those two (2) brands

[DanThe]

Superpro have always been one piece trailing arm bushes in my experience, maybe they have changed recently but they are still being advertised as one piece here -

[reggid]

Superpro have always been one piece trailing arm bushes in my experience, maybe they have changed recently but they are still being advertised as one piece here -

Screen Shot 2023-10-25 at 09.48.32.png

https://superpro.com.au/find/superpro-c ... 00342/vid-

https://imageapi.partsdb.com.au/api/Ima ... anLvpHGWpk

i looked at these and they seemed to have a split in the middle but this appears to be the adjustable type only so my bad. They are locally made so will check them out

[flybynite]

To me it seems six of one or half a dozen of the other with those two (2) brands

Never had any need to use anything but OEM rubber in my E30 but in my experience in other cars SuperPro are a cut above Powerflex. SuperPro just seem better with less issues both in fitting/install and long term use. Seems to be the general consensus.

[fixedwheelnut]

I used Heritage Polybushes on my 335i Touring and I am happy with the ride.
Rear trailing arms, Rear axle beam and front wishbone.
The front and rear ARB are also polybushed but I used the ones from the kit they came in from @rix313