1980 SA22C RX-7: Barely a Survivor

79rex said:

Your about to find many weird things of owning a 79/80.  Including NLA brake parts.  swapping to 81+ is a good and bolt on place to look. 

'80 is a weird year, well so was '79 I guess.  One year only distributor with the ignitor assemblies on the fenderwell.  Front brakes are the same as '81-85 but with a different thread pitch on the hydraulics.  Struts are different height from FB, chassis is stiffer than FB because of the reinforcements in what would become the bin area (no bins in SAs).  At least you also get the FB style sunroof and FB style alternator, no points and external regulator like the 79s.

I also prefer the SA rear brakes.  You can adjust the shoes individually.  Downside is there are no self adjusters.

ALL single piston RX-7 stuff is NLA. You can't get reman calipers for any of them from '78 to '91.

dannyp84 said:

In reply to wcn2018 :

Let us know how you like the T3 rear links, I ordered them then sent them back when I realized they weren't going to solve my clearance issues. My upper links hit against the body due to the car's ride height, and adjustable links wouldn't change that. In the long term, I want to delete the uppers and do a tri link that goes through the floor to the interior crossmember and box in a mount there. 

The T3 parts look like a great way to destroy a shell.  The upper control arms describe a roll center somewhere around the roof, which is a long way from where the Watts link is, so the control arm bushings MUST be compliant.  If they are not, it will rip the upper link mounts off of the body!

It is an issue even with stock bushings, which is why Mazda used an 18mm rear bar on the SAs.  It keeps the suspension from articulating very much.

The best thing to do is use stock links and drill the bushings out in the upper arms to make them more compliant.  This will allow the suspension to move without giving you as much of a snap oversteer effect when the articulation meets the inability of the bushings to flex anymore.  My '81 has had this done and it drives very nicely, almost as well as the 3 link setup in my '84.

The later cars with 15mm bars had worse snap oversteer.  Mazda tried to help this by adding more roll understeer by moving the lower links down 20mm on the body, which also increased the binding issue, which is why S3s are the most common to tear the links off of the body.  (Which is why my '85 and my '84 were three linked)

Any suspensi9n will work....  if you don't let it!

In reply to Pete. (l33t FS) :

what you describe worries me, but im not sure i know what you mean. are you saying the rear link geometry places the roll center near the roof, compared to the center point on the watts that would be higher, which would want to force the body of the car towards the outside of a turn relative to the axle and strain the bushings laterally? the t3 links are much more compliant than the stock links in my opinion. being a ball joint, they have quite a range of free motion in all directions. but they have no lateral compliance compared to rubber, is that the concern?

ive noticed decreased binding and better rear axle articulation with t3. i also took off the rear sway bar. when i ran the car bone stock last year, the rear would slide so much due to the axle not wanting to articulate in corners and lifting the inside tire. i still lose one tire sometimes, but im ascribing that to an open diff.

i would imagine the lack of lateral compliance could be made up for by an induced diagonal travel on the t3 links. since they are ball joints they would all swing the axle towards the inside but also pull it forward some. i left the watts link arms with urethane, and the center pivot arm has the original rubber. that should allow the induced fore/aft motion to take place. ill have to keep an eye on the 4 link mount points for stress as you mentioned, and look excessive wear on the rubber components on the watts.

this also gives me some worry that the dshaft yoke is getting bottomed out in the transmission

wcn2018 said:

In reply to Pete. (l33t FS) :

what you describe worries me, but im not sure i know what you mean. are you saying the rear link geometry places the roll center near the roof, compared to the center point on the watts that would be higher, which would want to force the body of the car towards the outside of a turn relative to the axle and strain the bushings laterally? the t3 links are much more compliant than the stock links in my opinion. being a ball joint, they have quite a range of free motion in all directions. but they have no lateral compliance compared to rubber, is that the concern?

ive noticed decreased binding and better rear axle articulation with t3. i also took off the rear sway bar. when i ran the car bone stock last year, the rear would slide so much due to the axle not wanting to articulate in corners and lifting the inside tire. i still lose one tire sometimes, but im ascribing that to an open diff.

The rear suspension must have a lot of compliance in the bushings or it will not work.

Here is a test you can do: Support the car by the body, remove the stabilizer bar and the rear springs, and support the rearend in the center at ride height.  Unbolt one of the upper links.  Articulate the suspension, and watch as the bolt hole will not line up unless the link was an inch longer when articulated one way, or an inch shorter when articulated the other way.  That is what I am talking about, the two different roll centers mean the bushings must all have an amount of compliance.

The rear suspension links must be soft and compliant if the rear suspension is to move.  If you replace the bushings with solid joints, the suspension will not be able to articulate without tearing the links off of the chassis.  That difference in length has to come from somewhere.

A company that offers solid joints for the rear suspension, when these issues have been known literally for 45 years, indicates that they are either not capable of engineering performance components, or they are not interested as long as they get your money.

The racing fix was to replace the upper bushings with roll bar padding, and install a 3rd link aka "traction bar".

In reply to Pete. (l33t FS) :

well if i tear out a body mount, ill have a 3 link setup lol

i have so many axle housings sitting around. ill build one of them for 3 link while i run the solid links. thanks for bringing up that concern.

but im sure technotoy is more scrupulous than youre giving them credit for. proof is in the seat time. the car feels a million times better like this.

wcn2018 said:

In reply to Pete. (l33t FS) :

well if i tear out a body mount, ill have a 3 link setup lol

i have so many axle housings sitting around. ill build one of them for 3 link while i run the solid links. thanks for bringing up that concern.

but im sure technotoy is more scrupulous than youre giving them credit for. proof is in the seat time. the car feels a million times better like this.

I'm passionate about it because these cars were a dominant force in racing and all of their handling issues were known, and well known how to handle, and the stuff they sell makes zero sense other than bling at best, and actively makes the cars handle worse at middle, and destroys rare and hard to find parts at worst.

Like the steering gearbox brace.  WTF is that even for? The gearbox mounting has no flex issues, larger issues are loose wheel bearings and the front frame rails eventually crack at the tension rod/sway bar mounting points.

I mean, I would love to have another SA, but a decent one is close to $20k now, even decent FBs are over $10k, and TTT's hardware is going to make them even more hard to find and expensive after people start ripping the shells apart or backing them into ditches when the snap oversteer goes from an "uh oh" level problem to a '75 Porsche 930 level problem...

wcn2018 said:

In reply to dr_strangeland :

yea its binford in kent!

autox at evergreen should be slowing down a bit over the next few events from what they said. 

thanks for the support! great to see more SA owners. i have some parts laying around and if you need anything feel free to ask i may have it. Also, id rebuild the carb first and delete air pump for headers. night and day.

That's awesome, thank you.

Someone already deleted the air pump. And the entire rotary engine... It has a 305 small block chevy. It's a little sad to me because I'm a rotary fan, but I'm hoping it's a cheap way to make power and not have to fiddle with it too much.

Evergreen definitely runs less events in the winter, that's true. Given that most clubs shut down completely until March or so, it's still better than nothing.

In reply to dr_strangeland :

well i mean the autox events stop filling up so quickly on sign up, so it should be easier to sign up for winter events

Did RMS and stat gear o ring yesterday. swapping on a racingbeat lightweight steel flywheel that i sourced used with the right 79-82 counterweight. got it machined at autosport ballard. cool shop there i think theyre focused on minis.

would like to start this car with just the flywheel on to do a low tech inbalance check at idle. unfortunately i need the transmission on to have a starter. ill just have to disassemble it again if i notice a vibration and put the old flywheel on. either way its getting a new clutch kit. old TOB was super nasty.

noticed brake fluid in the boots of the new (old) calipers. so i decided to rebuild them last night. these are in better shape than the last pair but not perfect. the pistons for both are in great shape though so they should seal fine. the integrated parking brake is one of the worst things ive ever had to reassemble.

also did shift bushing and input shaft seals on transmission. will be fabricating a polyurethane mount for the crossmember. more on that later. would also like to route the transmission breather somewhere where it wont spew gear oil mist all over the trans tunnel perpetually. 

rear axle is installed now too. we are inching very close to having disc/lsd finally.

also, i noticed this wear on the rear stat gear bearing. im not terribly concerned, will definitely continue to run this motor. do any rotary experts care to weigh in? gear is oriented as one would see it while looking at the flywheeel.

Pete. (l33t FS) said:

wcn2018 said:

In reply to Pete. (l33t FS) :

well if i tear out a body mount, ill have a 3 link setup lol

i have so many axle housings sitting around. ill build one of them for 3 link while i run the solid links. thanks for bringing up that concern.

but im sure technotoy is more scrupulous than youre giving them credit for. proof is in the seat time. the car feels a million times better like this.

I'm passionate about it because these cars were a dominant force in racing and all of their handling issues were known, and well known how to handle, and the stuff they sell makes zero sense other than bling at best, and actively makes the cars handle worse at middle, and destroys rare and hard to find parts at worst.

Like the steering gearbox brace.  WTF is that even for? The gearbox mounting has no flex issues, larger issues are loose wheel bearings and the front frame rails eventually crack at the tension rod/sway bar mounting points.

 

I mean, I would love to have another SA, but a decent one is close to $20k now, even decent FBs are over $10k, and TTT's hardware is going to make them even more hard to find and expensive after people start ripping the shells apart or backing them into ditches when the snap oversteer goes from an "uh oh" level problem to a '75 Porsche 930 level problem...

Seconded. My excitement that someone was actually building parts for the FB chassis quickly faded when after looking at some of their stuff it appears they never took the time to learn the chassis. Dave from Mazdatrix was supposed to send me photos of his Tri Link setup used on his old race car, so that I could reference the design, but he never got around to it. If you're willing to build a forward mount inside the car for the upper link, and then box it in, the process could be fairly simple, as you could retain your 2 factory lower links. 

"also, i noticed this wear on the rear stat gear bearing. im not terribly concerned, will definitely continue to run this motor. do any rotary experts care to weigh in? gear is oriented as one would see it while looking at the flywheeel."

In reply to wcn2018 :

Copper showing at the puzzle joint for the bearing is normal.

In reply to dannyp84 :

I was under my car so I snapped a couple of pics of my tri link. Rules don't allow bringing the link into the cabin, so the bracket bolts to the under side of the tunnel. The bolts are placed to go through where the uni body sheet metal is overlapped. It requires the link have a bend in it to drop down from the top of the pumpkin to the mount in the tunnel. 

The link is offset slightly to the driver's side. It's a bit tricky to keep the link bolt from rubbing the driveshaft. The setup uses stock lower arms, and a panhard bar instead of the watts link. 

In reply to sevenracer :

I think id eventually like to do something like this too. hows the clearance with the driveshaft? would hate for those to contact.

are you using panhard? i think it would be nice to retain the watts link honestly. A spherical bearing at the center mount could eleminate the binding issue there. tri link eliminates the 4link binding issue. do you think the 3rd link could be routed to not interfere with the watts arms?

In reply to sevenracer :

Did you ever have issues with these ripping out? One of the racers I talked to said if the rules allowed he would've preferred to box the link in the cabin, as they would consistently rip themselves out with the bent arm method.

In reply to sevenracer :

That's a pretty clever solution. How is the bracket attached at the axle, welded on?

If this is the G-Force system, the axle mount is welded on.  

The watts link will hit the tri link stuff. You also want the roll center lower than the stock watts link puts it. Right about even with the bottom of the diff housing.

Yep, it's the G-force solution designed by a guy named Jim Susko. The mount on top of the axle is just two pieces of steel welded on.

Per another question above, proximity to the driveshaft is an issue at the front mount. I installed the original parts from Gforce just a bit off, and could not keep the front bolt head away from the driveshaft without significantly moving the axle over using the panhard adjustments. So, I wound up making a new front mount to move the bar over about 1/4" but still use the same mounting holes I originally drilled in the chassis. 

dannyp84 said:

In reply to sevenracer :

Did you ever have issues with these ripping out? One of the racers I talked to said if the rules allowed he would've preferred to box the link in the cabin, as they would consistently rip themselves out with the bent arm method.

I never had any issues, but I did hear some talk of that. I think that the design had been modified to resolve that by the time I bought my parts.

The bent arm method also breaks the bent arm eventually.

The solution I may do for my '81 involves using lower links on the upper and making brackets in the wheelwell for the links to mount.  A true parallel 4 link setup like the Group B RX-7s had, which was a near-as-dammit copy of the Group 4 Ford 3scort setup that every other successful solid axle rally car eventually used.  The RX-7 already had nice long lower links, just needed to make the uppers the same length and parallel.

(leetspeak to avoid filter)

I dont know yet since its not on the ground, but this new axle seems to not match the alignment of the previous one. in fact, it seems to bind so much that my jack actually lifts the car before the axle reaches the point where it usually sits on the ground.

t3 quoted a bracket and hardware kit that relocates the upper links to the outside with double shear. should resolve some of the binding and its $100 shipped. seems weird to double down on a product that's letting me down, but i need the car moving and dont have the time to do 3rd link/panhard rn. life is happening. its the holidays. vacation in february. im moving in march. 

its this, but add hardware:

https://technotoytuning.com/weld-on-parallel-4-link-double-shear-brackets-for-the-safb-rx7/

the good news tho.

man i would hate to peel my fresh epoxy 2k and undercoat off the wheelwells to weld on a stopgap measure. chocies choices.