Suspension Bushings
 

So, my recently acquired FD has a full set of ten year old Delrin bushings on it. These were the bushings that some member of the old Rx7 mailing list, or maybe the old Rx7 forum, had made and sold to quite a few people.

I think some of them have worn poorly or something, but the poor car rattles and clunks around and sounds like an old truck.

I haven't had a chance yet to put it up on the lift and check everything. When I do, are there any usual suspects for the noise? I plan to replace all the bushings, but if there are a few I can hit first (before I do them all) to make a big improvement, I'd like to do that.

It looks like PowerFlex or SuperPro are what people are using now? Any reason to steer away from those or try something else? I wouldn't be adverse to an OEM set, but I hear they are very expensive in comparison to the urethane aftermarket kits.

Thanks

Edited to add: Actually, these are the Jim LaBreck/Unobtainium bushings, which may be Nylon. I'm not exactly sure. I am sure they are noisy/clunky as hell.

Dave-

I just recently did all the bushings on my FD. After reading through a bunch of threads and weighing the options, I went with the OEM pillow balls, but purchased Mazdaspeed (Mazdacomp) bushings for rear upper links and lower arms.

Another source of my clunking turned out to be diff mount bushings. For those, I just purchased new OEM Mazda bushings.

I'm a MazdaComp member/racer and just checked their parts list... couldn't find anything under the competition parts other than a single control arm bushing.

Do you mind sharing the part numbers for the OEM and MazdaComp parts you bought?

Dave, I too had terrible noises from the rear of my car, replaced the Pillowballs with spherical units from J-Auto and ALOT of my noise went away. But I plan on doing the remaining rears in poly units as well.

I drive the Black LS swapped FD I think we spoke about my cluster issues at Chilhowee.

To be honest, I just went to 93-95 Rear Suspension Bearings and Bushings and bought them directly from Mazdatrix (I am not a MazdaComp member).

MazdaTrix is still around !?

Cool, I forgot about those guys.

Yeah... Delrin will rattle your fillings loose. I bet they were Unobtanium made by Jim Labreck.

I'm debating replacing all my bushing with OEM or a combination of OEM pillowballs / SuperPro poly bushings. Car is a street car, but will hopefully be making a bit of power.

Surprisingly, price different between OEM and SuperPros is fairly comparable.

What are the Mazdacomp bushings made out of? 95A poly?

Poly is stiff and requires maintenance. Unless you need the stiffer bushes, OEM is the way to go. Believe Mazcomp is stiffer rubber (but not as stiff as poly), so that's a good compromise.

stiffer rubber.

List of MazdaComp bushing part numbers for the FD. Described as 40% stiffer than stock. There may be others.

Part No : F128-34-480
BUSH., FRT UPPER ARM

Part No : F128-34-460
BUSH,LOW CONT ARM (F/F)

Part No : F128-34-470
BUSH,LOW CONT ARM (F/R)

Part No : F128-34-471
BUSH,LOW ARM SUPPRT(FT)

Part No : F128-28-8C0
BUSH, UPPER ARM (REAR)

Part No : F128-28-460
BUSH, LOWER ARM (REAR)

Part No : F128-28-52Y
BUSH, TRAILING LINK(RR)

Part No : F128-28-42Y
BUSH, TOE CONTROL (RR)

Just putting 2 and 2 together here.
I have a set of skateboard wheels that I only use for parks and stuff because they're too hard for the street.
Guess what they are made out of? 95A Polyurethane.


Whoa. *puts down thew weed* :lol:

SuperPro and Powerflex bushings are not made out of hard poly and don't require constant maintenance. SuperPro says their poly formula is comparable to stiffer rubber rather than your stereotypical hard poly material such as Natey's skateboard wheels :lol:

I have nothing but happy customers, male and female, running SuperPro or Powerflex bushings on their FD. Powerflex has a black colored line of poly bushings which are stiffer than their purple street bushings in case you're looking for something stiffer but even those are still tame compared to hard poly bushings of the past.

I've had SuperPro bushings on my FD for over 6 years or so and I've never maintained them in any way since the day I installed them. My car gets driven rain or shine on the street and gets driven to/from track events so it's far from a garage queen. My daily driven BMW has Powerflex bushings (mix of black and purple) with no ill effects. My wife hauls the kids around in it with no complaints about ride quality or noisy bushings.

SuperPro and Powerflex offer a life time warranty on their bushings which is nice to have. Just wanted to give some real world feedback from someone who deals with these bushings daily. These are definitely not your average, run of the mill hard poly bushings :)

Does SuperPro actually publish what their "hardness" is? The best I could find on their website was "specially blended Polyurethane"but I don't know if that's closer to 95A or 60A... or maybe that's what they consider their "special sauce"?

Since you see more then a few, you have any guesses/info on their hardness? I was a click away from ordering SuperPros... but the MazdaComps have me thinking.

-M

Juan is right powerflex or Superpor is the way to go .I got a set of powerflex from him 3 years ago and love it.

Their poly blend is their special sauce like you put it but I find it's very similar to Powerflex's poly. It's almost impossible to distinguish an FD with SuperPro or Powerflex purple bushings with the 'ol butt dyno. They both feel great. I've never installed or been in an FD with Mazdacomp bushings so I can't say how they compare to poly bushings but I wouldn't be surprised if they felt similar. Honestly, you can go wrong with any of these bushings (SuperPro, Powerflex, Mazdacomp). The biggest drawback I can see with Mazdacomp, and stock Mazda bushings, is their price.

If SuperPro and Powerflex were harsh,noisy, annoying bushings only suited for a hardcore race car, I'd be the first to tell you guys not to mess with them and buy genuine Mazda and/or Mazdacomp bushings. If being miserable in your street/dual purpose FD is what you're after, then I recommend delrin bushings. I've had customers tell me that their significant other will once again ride in their FD after getting rid of delrin bushings :crackup:

PS.
I too was skeptical when I bought my SuperPro bushings (paid full price as a regular customer) for my FD which was bone stock at the time but I've been a satisfied customer since then. :nod:

Has anyone heard/ or used Mark's Engineering pillowball bushings?
FD3S Rear Pillow Ball | Mark's Engineering Pty. Ltd

When I switched from stock to Super Pro poly on my FD in 2013 what I noticed was a bit more "feedback" in the steering wheel and more "white noise" over rough/textured pavement over stock, but so far no weird noises or harsh ride.

Poly busings do change the feeling of the chassis compared to stock bushings. Its mostly on braking/turn in as the stock bushings are "sliding" bushings that alter the front toe geometry.
The poly bushings deflect very little in the fore/aft direction. It makes the chassis feel more true to input to me, but others might find it a tad less "forgiving".

It is my opinion that in the rear suspension you should only change the upper arm inner bushings to poly as all the other bushing locations in the rear are multi-axis and the poly will introduce some degree of binding.
Stock or Mazda Competition is the way to go for the other points in the rear in my opinion.

I don't have any experience with the Mazda Competition bushings on the FD, but on the FC they were right between stock and poly in terms of their effect on performance and comfort.

This is what I recommend. Others have there opinion but this is from first hand experience on my personal fds, our shop fd, countless track events, and over 100 cars I've done bushings on.


Either Super Pro or Powerflex bushings from J-Auto. Juan correct me if I'm wrong but the Powerflex kit just has more bushings (swaybars, rear lower inner control arm bushings).


Oem or the J-Auto pillow balls and dust seals. I've used both. The J-Auto are significantly more affordable.


Mazda oem rear lower control arm inner bushings.


Superpro or Powerflex toe link and trailing arm bushings. I don't like the aftermarket arms with spherical bearings for the street because they wear out quickly.


I don't like how the stock suspension allows the toe to change under braking. I find eliminating this makes for a more predictable car.


I have NEVER had a Superpro or Powerflex bushing fail or make noise when installed at my shop. Most issues can be traced down to installation error.

just wondering if anyone has a picture of the rear bushing breakdown, showing part and part name in a picture for ease of ordering?

Might want to try the FSM (Factory Service Manual). I believe there is a link in the FAQ.
Juan might have posted one too in the suspension section but not sure.

https://cimg9.ibsrv.net/gimg/www.rx7...00b38fc424.png


Hopefully this helps