Suspension Bushings Selection Discussion

[RETed]

Since I still have all the stock suspension bushings in my S5 T2, and they are all starting to show the usual signs of age/wear (i.e., drying/cracking), I plan to replace them all this winter.

For background on my setup, I replaced all the springs with Racing Beat springs for the T2 and replaced the struts with the adjustable KYB AGX units. This was back in 2006, and the bushings all looked good at that time. I’m still running the stock tire size on stock wheels, along with the stock sway bars/end links.

I'm happy with the way the car handles and with its ride comfort quality, and I don't want to compromise either with my new bushing selections, so my objective is to retain that. I also don't want to increase NVH characteristics or decrease durability - since bushings are generally a PITA to replace, I don't want to have to do it again in a few short years.

One other thing, which I think has to do with the DTSS rear steer bushings is that when I push my car to 9.5/10's of its limit, I’ve noticed the rear end feels a bit squirrely to me when the DTSS starts to take over - my guess is those bushings are shot and need to be replaced too. Not sure if I want to do away with the DTSS functionality or try to retain it the way it was designed in, as I’ve never driven an FC with a known “working” DTSS to form any opinion on it.

From my market research, seems that the bushing options for everything except the DTSS bushings are: (a) Stock Mazda/OEM bushings; (b) Slightly stiffer Mazdaspeed stock bushings (still rubber); and (c) & (d) polyurethane bushings from either Energy Suspension or Prothane. Of the (c) & (d) options, I think the Energy Suspension (c) bushings are marginally better simply because they are impregnated with graphite, which should help keep them a little quieter and durable over time. Both brands are available “ala carte” or as complete kits that cost about the same and replace all stock bushings except for the DTSS bushings.

As for the DTSS bushings, I think the only replacement option is to buy the Delrin DTSS eliminator bushings that Racing Beat or Mazdatrix sells. As far as I know, Mazda doesn’t sell the stock DTSS bushings separate from the rear carrier assembly – can anyone confirm if this is still true?

Next question – Would it make any sense to mix & match stock Mazda, Mazdaspeed and Polyurethane bushings? i.e., a mix of (a), (b) and (c/d) parts to fine tune what I’m trying to achieve here? My gut feeling (disclaimer - not based on any real suspension tuning expertise) is to go with the polyurethane parts for the sway bar bushings, but use stock or stiffer Mazdaspeed rubber bushings for the front & rear control arms. If stock DTSS bushings can’t be had ala carte, then I suppose only viable option there is to go with the RB DTSS eliminator bushing (delrin)

Thoughts & recommendations?

[Pete_89T2]

Since I still have all the stock suspension bushings in my S5 T2, and they are all starting to show the usual signs of age/wear (i.e., drying/cracking), I plan to replace them all this winter.

For background on my setup, I replaced all the springs with Racing Beat springs for the T2 and replaced the struts with the adjustable KYB AGX units. This was back in 2006, and the bushings all looked good at that time. I’m still running the stock tire size on stock wheels, along with the stock sway bars/end links.

I'm happy with the way the car handles and with its ride comfort quality, and I don't want to compromise either with my new bushing selections, so my objective is to retain that. I also don't want to increase NVH characteristics or decrease durability - since bushings are generally a PITA to replace, I don't want to have to do it again in a few short years.

One other thing, which I think has to do with the DTSS rear steer bushings is that when I push my car to 9.5/10's of its limit, I’ve noticed the rear end feels a bit squirrely to me when the DTSS starts to take over - my guess is those bushings are shot and need to be replaced too. Not sure if I want to do away with the DTSS functionality or try to retain it the way it was designed in, as I’ve never driven an FC with a known “working” DTSS to form any opinion on it.

From my market research, seems that the bushing options for everything except the DTSS bushings are: (a) Stock Mazda/OEM bushings; (b) Slightly stiffer Mazdaspeed stock bushings (still rubber); and (c) & (d) polyurethane bushings from either Energy Suspension or Prothane. Of the (c) & (d) options, I think the Energy Suspension (c) bushings are marginally better simply because they are impregnated with graphite, which should help keep them a little quieter and durable over time. Both brands are available “ala carte” or as complete kits that cost about the same and replace all stock bushings except for the DTSS bushings.

As for the DTSS bushings, I think the only replacement option is to buy the Delrin DTSS eliminator bushings that Racing Beat or Mazdatrix sells. As far as I know, Mazda doesn’t sell the stock DTSS bushings separate from the rear carrier assembly – can anyone confirm if this is still true?

Next question – Would it make any sense to mix & match stock Mazda, Mazdaspeed and Polyurethane bushings? i.e., a mix of (a), (b) and (c/d) parts to fine tune what I’m trying to achieve here? My gut feeling (disclaimer - not based on any real suspension tuning expertise) is to go with the polyurethane parts for the sway bar bushings, but use stock or stiffer Mazdaspeed rubber bushings for the front & rear control arms. If stock DTSS bushings can’t be had ala carte, then I suppose only viable option there is to go with the RB DTSS eliminator bushing (delrin)

Thoughts & recommendations?