FWIW the Mustang rear shocks fit just fine. The chassis runs out of compression travel long before the shocks do.

Source: I have AGXs on the rear of both of my RX-7s. One of them has the shock mounting eyes moved a lot to increase droop travel to the limit of driveshaft plunge. No problems with the shocks bottoming out.

They aren't great shocks but they are acceptable. 4 seems to be the best setting. The adjustments are extremely coarse.

 

Honored to have you @peejay comment on this thread. I agree on the coarseness of the settings.

 

I have AGXs on the front of my '84, too. FC front suspension and all that. They only have four positions! 1 is a worn out Buick LeSabre and 3 is really stiff. I never tried 4.

I honestly think that all AGXs are valved the same, for all applications, and they are adjustable only so KYB can leave the problem of valving up to the user

This is where I start rambling about how my Volvo has accelerometer adjusted electronic dampers with three ride settings, Comfort, Sport, and Advanced. I don't think the suspension actually moves in Advanced. But it's really fun to play with the shock adjustments from the drivers seat! And it's really neat how you can fly over a dip in the road and the car just flatly launches out and settles back down.

 

Mazda had that in 1986!

 

Yeah, but 20 years later you can still buy new shocks and struts

 

So the shocks arrived today and I've been at it. The AGX went in super easy; as expected I had to cut down the lower mounting bolt sleeve from ~1 1/2" to 1 1/4" to fit into the axle's ears.

The Konis in the front though! The 8641-1072SPORT body length is 14 3/16" where the old Tokicos are 13 15/16", the effect being they bottom out and sit about 1/4" proud of the FB strut tube and the gland nut only engages about 2 threads. I'm not the only one to run into this, although some were way too tall at 1" proud of the tube.

@j_tso , I saw your post

https://www.rx7club.com/1st-generati.../#post12365522

Any advice before I have at it with the hack saw? Is there much risk I'll let out the magic gas?

Thanks

 

The thought crossed my mind when I did it, but nothing happened.
I cut just the nub at the end like in the linked thread.

 

Some notes on installing the Koni strut cartridges in an FB strut tube.

- I ground down the nubs from the bottom of the cartridges and there was enough metal to take off sufficient height and still have plenty of strength.
- For the spacer, I ordered the 17mmx15mmx20mm sleeve bushings. They were just slightly too big to fit into the Mevotech top mount inner bearing, so I relieved it with a longitudinal slice.
- The 12mm length would have been too short as the space ring just below bearing is the same ID and bearing (makes sense as the shaft needs to pass though it), so I trimmed it to 18mm length. The leftover in the photo shows just how little needed to be trimmed. keeps the spacer centered.



-Also (and maybe this isn't weird?) I had to assemble and tighten the top mount assembly first because once you have the Koni in the strut tube, the flats to keep the shaft from spinning are hidden under the perch.

Edit: Looking at the photos now, it seems like I would be able to get a wrench in there, lol. Anyway I did it the other way :P



So I had to tighten the gland nut last, through the assembled strut. Fortunately, the RB springs are pretty short and you can compress them enough with straps.

 

Or.... you can use ZX2 top mounts, which have a D hole for the strut shaft similar to an FC, and cut a flat into the strut, so the strut locks in place.

Need to either drill out the strut towers for 10mm studs or swap the studs for 8mm ones.

The ZX2 mounts look like a cross between FC and FB... its FB bolt pattern and strut mount height but FC style strut mounting.

I did this when I installed Koni Yellows in my FB. (Difficulty: I had FC knuckles.... and the strut inserts were for the back of a WRX so I made strut housings out of two pairs of dead Impreza rear struts)

 

All installed and I took a short test drive. I have all of the settings on the softest and it's very different, reminds me of the OE springs and shocks. Looking forward to playing around with the settings. First I have to fix an almost stripped lug hole on the right rear axle flange.


Thanks everyone, especially @t_g_farrell for all of the research!

 

Just a finishing touch suggestion for those folks using the Mevotec branded top mounts. While the stock strut access holes and caps are 1.5" in diameter, the Mevotec ones are only 1.25" and the OE caps, unsurprisingly, don't fit.

I got these and they seal tightly, after a good firm press to seat them.

 

What spring options do we have other than the RB springs?

I was looking to go with the shocks/struts option but the limited springs availability will probably make me buy BC coilovers instead....

 

Google is your friend. Looks like there are options our there. You could also just measure things up and get some from Summit or JEGS as well.

 

Would you need to cut the bump stops if you don't cut the RB springs? Im in an 85 GS, and I'm getting ready to install the RB springs, KYB Excels up front, and the AGX adjustable in the rear.

 

I don't think so. The RB will actually might raise the ride height a bit if your old springs are really worn out, so don't be surprised.

 

Awesome, thanks for this thread @t_g_farrell ! Going to post about this on my build thread when I finish up.