Winter Plans - Suspension/Rubber Refresh
 

This winter (which is rapidly approaching) I'm planning to do a complete suspension refresh on my '85 - ideally anything that is rubber (that I haven't already done, like brake lines) will get replaced, and I'd like to do shocks/struts as well. This car is my summer daily driver with occasional autocross (for fun, not in it for the competition aspect), and has 180k miles. As far as I can tell, it's all or mostly original underneath. I do have a couple questions though, since I'm not as familiar with the FB chassis as other cars I've worked on.

1. Any recommendations on suspension bushing kits? Could piece it all together but sometimes it's cheaper and easier to find a full set.
----- 1a. Rubber, poly, or a mix? I've heard of issues with binding in the rear with poly bushings
2. Non-suspension rubber - I know I'll be looking for engine mounts and a trans mount - any recommendations there?
----- 2a. Are there any other non-suspension rubber bushings I should be aware of (other than exhaust hangers - already did those when I put on the RB system)? I think I recall something about crossmember bushings?
3. Shocks/Struts - this is a daily with spirited drives and some autocross. It could be a little firmer but the roads here are pretty bad so I don't want to take it too far. Any recommendations?
4. Springs - The rear driver's side of my car sits a good inch (if not more) lower than the passenger's side - I imagine this is spring sag? In any case, should I plan to re-use my old ones or are there good replacements around?
----- 4a. I'm not opposed to a slight drop if I do replace the springs, but I have heard bad things about the rear geometry of these when lowered, especially if I use poly bushings
5. Alignment - Any reason I can't set the toe myself and just turn the strut mounts for caster/camber and save having a shop mess with it in the spring?

1. Just get a urethane kit from RacingBeat or Mazdatrix. Do not replace the rubber bushings in the trailing arms, just do the swaybar links and the watts linkage in the rear and the swaybar links, the tension rods in the front and the lower control arm bushings. You may also want to pickup a Moog idler arm as well. Its a great upgrade. You may want to replace the tierods and ends as well if you are doing this.
2. Go to Mazda or Mazdatrix and get the OEM rubber engine and tranny mounts. If you want harder engine mounts just get hockey pucks and drill them ( I know you know what hockey pucks are!) Other items to replace would be the bump stops in the rear.
3 & 4. I would recommend the RacingBeat springs and better shocks like Tokico blues or adjustables.
5. You are best to do it yourself, alignment skills these days are very scarce in most shops. Just use the string method and point the mounts inward to the rear of the engine bay and you should be good.

Thanks! I'll look in to the RB or Mazdatrix kit. In terms of the trailing arms, are rubber replacements available? I won't know for sure until I pop the arms out but I can't imagine they're not pretty well worn out after 32 years and 180k miles. I'll look into the OEM mounts - that's pretty cool if they're still available! I'm frequently impressed with how much you can still get from Mazda for these cars.

This isn't the first I've heard of the Tokico blues - sounding like a good option (always a good sign to get the same recommendation multiple times from independent people!). They would pair well with the RB springs, I take it?

Other parts of the winter plan include rebuilding the whole steering linkage (including the new moog idler arm), replacing the oil pan gasket (leaks profusely at the moment), and adjusting the steering gear - part of why I asked about alignment. I'll just plan to do it myself, thanks!

I believe mazdatrix has some NOS rear arms. Fox body Mustang rear shocks fit in the rear as well if you can't find blues, I have the KYB Gas-A Just in mine and they are really nice and stiff. Check out the write ups on the steering gear so you adjust it correctly. If you have the money get some adjustable camber plates for the front, it will help you on the auto X course

I have the KYBs with the RB springs and they can't handle the spring rate very well. Some jouncing and porpoising. You don't want to replace the rubber in the trailing arms, you just get new arms with new rubber in them. At this age they are probably kind of hard versus soft. You may want to delay doing them until you get all the rest done and see how it feels.

Are you guys recommending poly bushings in the Watts Link (pivot and joints), and stock OEM rubber bushings for the upper and lower arms?

going to be digging into this soon, and want a good street setup like the OP is asking for. TIA,

they aren't NOS, Mazda actually has parts for these things

Yes and poly on the swaybar if you have one in the rear. Poly on the arms is a no-no especially on the lower ones from what I've read.

Interesting, I wonder why no one can make new rubber bushings then...

A look at the original four links and you'll see the bushings are vulcanized to both the arm ends and the sleeve mounting bolt goes thru therefore new bushing means new arm...

Everything I have read suggests no poly on the watts. If it’s mostly a daily and you don’t expect to be competitive at autox, then just get an all rubber kit. Less squeaking, less jarring on roads. Combine that with Tokico Blues, Racing Beat springs, and a Racing Beat front sway bar and it will be plenty stiff and sporty. The sway bar comes with poly bushings and those are ok to use, but I’d leave everything else rubber.

That is true but theres no reason it couldn't be pressed into the arm or urethane ones softer than standard poly bushings...

Sorry for going MIA - work trip. Thanks for all the input, lots of good things to consider - especially the new rear arms with bushings from Mazda!

Here's another related question - for the motor and trans mount, I've found what I assume are OEM ones from Atkins and other places for about $38 a piece. Meanwhile, I can get aftermarket rubber mounts for $8-9. Is there that much benefit to the Mazda mounts over the aftermarket ones to justify an extra $90+ between the three?

You can use hockey pucks drilled for the engine mounts. The tranny mount is a special shape, best to stay with OEM on that.

I have polyurethane everything in my car and love it, not sure why everyone gripes about it. There must be one or two threads that everyone finds and uses to argue against it with no personal experience.

https://cimg2.ibsrv.net/gimg/www.rx7...0489f64ffd.jpg
https://cimg3.ibsrv.net/gimg/www.rx7...6dd536f4d6.jpg
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https://cimg5.ibsrv.net/gimg/www.rx7...e76973c67e.jpg

I done full poly bush in the rear of my car and it has been fine so far. The car seems a lot more together and refreshed, making the ride a lot nicer

look at you and your working 7... sorry in a dark spot right now.....

Do you track your car?