Trailing arm bushings, I needs 'em

[Fairtax4me]

Like I said, I needs 'em. I'm looking for replacements that are tougher than the bowl of jello stock bushings, but not polyurethane tough.

I was thinking of Group N bushings, but think those might be too tough still. I want SOME pliability, just not as much as the stock bushings. Wondering if WRX or STI bushings are like the happy medium? Or should I just go for the group n bushings and save like $20? (They cost less)

[cal_look_zero]

I've heard that the SuperPros are tougher than stock, but not solid poly like Whiteline or TIC.

 

http://www.rallysportdirect.com/Super-Pro-SPF1907K-Rear-Trailing-Arm-Bushings

[idosubaru]

Is it possible that a brand new OEM bushing would be fine? maybe the aged degenerate OEM bushings you've come across are not that good but they're fine when new?

[Fairtax4me]

I stay away from poly bushings for the most part because I've seen too many wear out in the center and allow play in the bushing. If I have to take them apart and clean and re-grease them every 6 months its not worth it to me.

 

Gary I went to the dealer and checked a set of new stock bushings and they were pretty soft. They didnt have the WRX bushings in stock and didnt want to order them unless I paid for them.

I figured they must be a little stiffer than the Legacy bushings but I'm trying to figure out just how much stiffer are they before I order them.

The group N bushings are actually the cheapest of the bunch at only about $19 per. And I know those will be pretty solid, but does saving $10 mean I'm gonna feel every time the rear wheel runs over a caterpillar in the road? The group N motor mounts I bought transfer a ton of nvh, I can only imagine the other bushings will be the same way.

WRX bushings are right in the middle at about $25 per.

Stockers are about $30 per.

This is only the front bushings, the rear bushings seem to be fine.

[presslab]

I've had Group-N motor mounts, and yes they are harsh! But when I replaced the trailing arm bushings in my GL-10 (yes, different design) with urethane I didn't notice any more NVH. The distance from the bushing to the wheel is pretty far in both cases.

 

I don't think the Group-N bushing NVH will be a big deal. You could also do the zerk fitting with urethane (like I did) if you're worried about wear. I do agree though that urethane is not ideal for a lot of applications.

[Fairtax4me]

Right, my only concern is that this is the bushing that keeps the wheel from moving fore/aft when you hit a bump. With a stiff bushing, rather than absorbing that lateral motion, it would transfer to the body. I kinda like the soft ride I have now, other than the thump/clunk I occasionally get from the worn out bushings that are there. You know those speed humps they put everywhere to make you slow down to like 10 mph? I usually roll those at about 30. The rough railroad crossings around here that people usually cross at not much more than a snails pace I do the same way, roll over them at about 25-30 and the car just sorta walks over them. I like the soft floaty feel because the tires stay glued to the surface on the gravel and dirt around here. So you can sorta see my usual driving style. Have no doubt that helped lead to the demise of the current bushings. :-p

 

Here's a question I haven't found a clear answer to, are stock STI bushings already Group N? Or is the Group N set the next step above stock STI?

[presslab]

The urethane will increase road noise somewhat and transfer more high frequency vibration, but I've never felt it made bumps any harsher as those are relatively low frequency.  My car doesn't have any soft floaty feel like yours, but I feel it handles fantastic both on pavement as well as off-road.  A few weeks ago I was on this dirt road with large holes all over it, about 6" deep on average.  I was pleased with how fast I was able to go while maintaining complete control and no harshness.  Then I finished out the drive on smooth curvy tarmac pushing well over the ton.

 

Opposedforces shows the front trailing link bushing on the STi as 20254FE000, and it's unique to the STi.  The link below shows the same part number as a Group-N part.

http://www.sti.jp/e/competitor/parts/e2.html

[Fairtax4me]

Possibly something interesting to others in here:

http://forums.nasioc.com/forums/showthread.php?t=2233376

 

Dunno how accurate his tester or test procedure is, but the scale should be pretty close.

 

Thanks for the link. I was comparing opposedforces part numbers with SP4Ys SPT parts list and they show different numbers. But reading threads about group N bushings some people said they had the same part numbers as the STI listings. Subaru shows different list prices for group n and STI bushings though.

[Fairtax4me]

So it seems that the rear bushings are the same for like everything. Legacy, Impreza, Forester, Base, L, Gt, Outbacks, Rs, WRX, STI, everything uses the same part number for the rear bushings from like 93 to 2007 (legacy only til 99).

 

WRX, RS, TS, Outback impreza, and Forester share a different front bushing.

 

STI uses its own front bushing apparently, which appears to be the group N equivalent. Trying to find pictures of them is more difficult than I though it would be.

 

Either way. The STI stock front bushing lists for $17. The "Group N" lists for $24.95. Which one you think I'm buying? :-P