RTAB Limiters

[TomCar]

I'm just about to change my H&R springs (which will be for sale shortly) for Eibach's in the hope of curing some perceived floatiness and thought I'd fit RTAB limiters whilst the back end was in the air.
My god... HOW MUCH? - for 4 pieces of plastic!

I've no doubt they work as described and will be beautifully made, but at £15+ each for a plastic washer (or £25+ for an ally one) there must be a better i.e cheaper way.
Does anybody know the dimensions of these limiters?
I've found a local 'washer-maker' and will be looking for something off-the-shelf to do the job. If I find anything I'll share the details for the benefit of others contemplating this.

Thanks
Tom

[Scooba_Steve]

Poly?

[TomCar]

The 'plastic' is actually UHMWP as supplied by Rogue, Vorschlag etc. Turner MS parts are aluminium but both will be dimensionally the same. If I fail with some custom washers, there are limiters on Pelican for $20 but shipping by DHL is $55, they have be available somehwere in UK for $20 price levels.

[Scooba_Steve]

If you're putting limiters on you're replacing the OE bushings, right?

Poly RTABs are about £40, no preload faff and I've not found them to be harsh or squeaky.

[exdos]

The cage in which the rear trailing arms fits does not have flat walls, therefore any limiter, which properly prevents lateral movement of the rear trailing arm, must be shaped to fill this void. In the case of a plastic/poly limiter, this requires the cost of tooling to make a mould for injection and would be prohibitive for making just 2 pairs for one car. In the case of aluminium limiters, these require machining and then the limiter would need to have threaded retaining holes put in them to keep them stable in the cage. I doubt if you'll actually save much if you factor in the cost of the time to produce 4 of them. I agree that, for what they are, they seem expensive, but they really do work and it's an effective mod.

[GuidoK]

I'd imagine the plastic limiters are made on a lathe or mill?
But it is indeed a complex shape with a concave center.
UHMWPE is not easy on a lathe (I'd recon you can use in this application better HDPE), milling is fine though.
I have no idea in what numbers these are made, but injection molding is expensive in low numbers.
Polyurethane is obviously made with a mold, but a much simpeler mold than for injection molding.
Maybe POM is suitable too.

[Argenta]

Several very affordable kits on ebay with both new RTAB's and limiters included.
Mine's are from AKG Motorsport.

[bony_13]

If you're putting limiters on you're replacing the OE bushings, right?

Poly RTABs are about £40, no preload faff and I've not found them to be harsh or squeaky.

This, although my experience is on 3.0i

[TomCar]

My RTAB bushes are in good condition, in the end I decided to go with Pelican limiters at $20 plus shipping, total around £50 delivered.
Looking forward to a more solid set up after new springs and a geometry, probably at BMTR in Birmingham. It will be interesting to see any differences following a track day eve at Donington. I'll get back with results in case any others are interested.
Cheers Tom

[Argenta]

Are all oem RTAB bushings the same?
From the base level 318 E46 to the M3 or Z4M, same part number..?

[AlfaScozzesi]

A few trawls through and there are also vorshlag limiters which seem to get a better write up.

Don't have a clue myself why they would be but I can go along with the Poly bush possibly binding on road use and why an aluminium limiter (Turner) is better than a plastic limiter but find it hard to believe that there will be much difference between two sorts of plastic limiter.

[PerryGunn]

A few trawls through and there are also vorshlag limiters which seem to get a better write up.

Don't have a clue myself why they would be but I can go along with the Poly bush possibly binding on road use and why an aluminium limiter (Turner) is better than a plastic limiter but find it hard to believe that there will be much difference between two sorts of plastic limiter.

Aren't the Turner RTAB limiters also teflon-coated? If so, I presume this would help prevent binding?

[TomK]

Are all oem RTAB bushings the same?
From the base level 318 E46 to the M3 or Z4M, same part number..?

no, I thought they were but it seems not. http://bmwfans.info/parts-catalog/33326770817/

eta: actually looking at that it's weird. Lists all E85 models but only M3 versions of E46 and E36

[AlfaScozzesi]

A few trawls through and there are also vorshlag limiters which seem to get a better write up.

Don't have a clue myself why they would be but I can go along with the Poly bush possibly binding on road use and why an aluminium limiter (Turner) is better than a plastic limiter but find it hard to believe that there will be much difference between two sorts of plastic limiter.

Aren't the Turner RTAB limiters also teflon-coated? If so, I presume this would help prevent binding?

I don t know and in the absence of anyone convincing me I will probably get the turner ones but has to be after the holidays and booked paint correction/ treatment.

[Argenta]

Are all oem RTAB bushings the same?
From the base level 318 E46 to the M3 or Z4M, same part number..?

no, I thought they were but it seems not. http://bmwfans.info/parts-catalog/33326770817/

eta: actually looking at that it's weird. Lists all E85 models but only M3 versions of E46 and E36

Indeed!
This is my kit: https://www.ebay.com/itm/401130364371

They actually display the correct part nr, despite listing all e46 & e85/86 cars...?

They did look identical to my old ones tho.
Its just that my rears feel a bit more sloppy than expected.