Polyurethane Rear Track Arms
 

I need to replace my rear track arms to get rid of that loud clanking noise. Does anyone know about European Parts Solution? Vertex Auto has those "upgraded" track arms, and they are polyurethane. How are the bushings compared to TRW? My goal is just to restore to the original ride, but those EPS arms are a little cheaper than TRW.

If you are talking about the long arms that bolt right behind the firewall & connect to the rear lower control arms, I don't see where they can use poly mounts. Problem with polyurethane is it is prone to binding, the last thing you want in a well designed suspension. You want the best bearing you can get there so get TRW made arms. I would be very wary of buying anything from Vertex. The floating captive nut that secures that bearing is easily damaged so be careful when loosening & torquing it!

Polyurethane can be a creaky, squeaky mess. Avoid!

Why would you say so? Is it the stuff they sell, or their customer service, or ...? Currently they seem to have the best price for those TRW arms.

Isn't Vertex refurbishing old arms that they trade when you buy theirs?

I think they did. But currently, they only offer 2 kinds for that arm, one is TRW, and the other is the polyurethane from European Parts Solution brand. Both of them don't show the core charge anymore, just one price.

Go for TRW then :)

I used Energy Suspension Poly bushings in a couple Hondas that I rebuilt. Lubed them with silicone grease. No squeak and they worked well. A little bit stiffer than the stock, but that was on a Honda.

All of the above, if are TRW arms should be ok.

I replaced mine with the poly- bushed ones from Vertex a year or so ago, sending back the used oem arms as "cores".
Have been very well pleased with them so far...
Didn't notice any floating captive nuts on mine.

I respect Byprodriver's knowledge, but I have had the vertex poly arms on my 02 S for years, and autocross the **************** out of it. They work fine. But, I will put TRW arms in at some point...

The Urethane bushing with a steel sleeve are a compromise they allow a little compression and extension. For street use softening the ride, which maybe isn't bad. For track use or autocross that little bit of flex affects toe and caster. This is why serious track driver switch to all mono-balls and solid, and billet bushing inserts. Its like running V and H rated tires instead of Y and Z recommended tires. They drive ok to a point but as you push them the flex isn't there and you experience more push and rear end slip. Continued use at higher speed can break down the side walls or cause tread separation's.

The final analogy is do you want to drive a sports car with the feel of a sports car or a sports car with the feel of a sedan.

Agreed. I was cheap when I bought them, and I wasn't tracking it then...

The captive nuts are attached to the underbody where the big bolt fastens the forward end of the track arm. I believe it is torqued to 118 ft/lbs.

You & I should respect Porshe's knowledge & think twice before altering Porsche engineering for which we pay so dearly. Good to hear you are having a good experience with your track arms, how many miles? No clunking noise?

And to confirm, the bolts and nuts should be torqued when the car is on the ground and loaded right? I imagine it would be very hard to reach those bolts with the car on the ground. I think I have read other people using a jack to load the arms, not perfect, but better than torquing them while they're hanging.

About 10K street miles and 12+ AX's on the Vertex arms, no clunking. The Porsche arms were clunking bad by 60K. The poly arms allow a little toe "excursion" at the track, it seems.

That does not sound like much fun...

Yes, put the car on stands and then use the jack to simulate the load. You'll know when you have the right load as the body begins lifting off the stand.

That's an interesting idea. Is this method better than driving the car onto ramps and then tightening?