hcaulfield57

iTrader: (1)

They’re about a year old, doubt they have more than 6,000 miles on them.

Do you recommend torquing the suspension by jacking the axle up or putting it on ramps? I generally do the latter, but I think it’s going to be tight, I guess I’ll see.

LongDuck

You don't need the wheels and tires on, he's just saying you need tk have ths weight of the car sitting on the rear axle, i.e., use your jack stands under the axle and let the body rest on the springs. This will ensure that your bushings aren't all torqued up when you install the links with the axle hanging freely.

This method also gives you plenty of room to install the mounting bolts. While you're under there, check the length of your rear bump stops. It looks to me like you're running eibach springs, which lower the rear end, and you'll benefit by cutting about 3/4" off of the bump stops to restore suspension travel before bottom-out. On even mildly worn RB springs, I was spending 1/2 the time driving around on my bump stops, and cutting them down made the car FAR more comfortable driving around town. Each is held in place with a single 14mm bolt running up the center. Cut them using a sharp razor knife, then carve them back into a semi rounded shape for more progressive engagement.

Also, have a close look at your Watts Links and pivot. Bad bushings here will result in a lot of rear vagueness as the axle slides back and forth while cornering. Those links and pivot are another $300 or so, but you might as well change them while you're in there if the rest of the bushings were worn. Even if not ezcessively worn, the rubber bets hard over time. You'll see just how hard when you go to cut your original, 35 year old bump stops!

hcaulfield57

iTrader: (1)

Okay, got everything installed. Some of those bolts are not possible to get a torque wrench on, so I just had to guess on the torque. I hate doing that, but dunno what else to do.

Wow what a difference though, the rear end feels totally planted and all of the harshness is gone. Turn in feels much better too. The steering felt really pointy and sharp last night after I went for a test drive. Unfortunately driving to work today the steering felt mushy and vague again. The car was outside last night, so maybe it's a tire pressure issue. Oh well, I feel like I've made at least some progress.

t_g_farrell

iTrader: (1)

Colder temps can have drastic affects on how tires ride and road feel. I noticed that with the temps lower lately the ride seems harsher and theres more vibrations coming through. This is because the tires I have on the car are summer performance rubber that gets too hard in the cold. Takes a long time to warm em up and smooth out the ride. Also the air pressure is a factor as well.

LongDuck

OP, did you cut down your bump stops? This has been a contributor to sudden snap oversteer when the suspension bottoms out prematurely on lowered cars. Its easy to do, as springs can be removed with a little effort just by lifting the body, then you can get to the bump stops to cut them.

Glad it's shaping up for you,

hcaulfield57

iTrader: (1)

I didn't cut the bumpstops yet, because I'm not sure if I'm going to revert to the stock springs or not. I didn't think they were available new, so was reluctant to modify them right away. If I keep the lower springs I'll cut it. But I totally see what you mean, there's maybe 1"-1 1/2" of clearance at best between the spring seat and bumpstop. The rear is feeling a bit bouncy, and I'm wondering if the rear driver shock is going out - would not surprise me due to how loose it was for like a week.

I plan on looking through the front suspension next, once I get my other car on the ground. My main irritation is the sloppy vagueness in the steering and poor turn-in. It's more frustrating that some days this seems to go away and the car drives fine. Went out to lunch today in the car, I've got about 1/2" of play in the steering at a stop. Once I start driving that play multiplies to like 1"-1 1/2" of play each direction and super soggy feeling. I know everyone will keep telling me it's my tires, and it's not that I don't believe you guys - they're certainly not great tires. BUT, could they actually sell tires this bad if it's all coming from the tires? Why would anyone else buy them? Maybe this car is just more sensitive to crap tires. I'm just reluctant to spend a bunch of money on wheels/tires if it's not going to improve anything.

GSLSEforme

It will,crap tires are crap tires period. You are underestimating what good tires can do for your(any)car,they are the link between steering wheel and the road. Good tires+wheels to mount the good tires(Konig) rewind 15x7" about $100 each, a GOOD alignment,change oil in steering box and adjust preload in box,play with shock adjustments=you'll think you're driving someone elses car.

Qingdao

iTrader: (3)

Yes they sell tires that bad... Its really hard to believe, but they do. What's even harder to believe (for me at least) is that people actually buy "the cheapest tire". When it comes to 13" rubber you don't have much option without spending the same amount on a set of 15" wheels and tires.

When my wife bought her Porsche the previous owner had just put NEW TIRES on it.... T rated tires.... It was pure sacrilege. 255/45/17 T rated tires. I didn't even know that was possible and who in their right mind would buy such crap. So yeah there are crap tires out there, and for whatever reason people keep buying them.


EDIT: I just remembered another set of brand new tires I threw away. Chen-shen tires. I got a bike a while back and I couldn't get those POS tires off fast enough. Plastic horrible tires. I tossed them in the trash with the chaulk lines from the factory still on them.

GSLSEforme

Ah,Cheng-shin,the k-mart of tires. They aren't the only junk tires out there(their ATV tires aren't bad),a lot of "private" brand tires are made overseas and sold here and are of dubious quality. Paying attention to more than just price is important when shopping for tires,tread wear,wet/dry traction,speed rating. For what it's worth,if you had upgraded your suspension in 1983 when car was new,tires would have been selected to complement work already done. There's no difference in 2017,tactics need to be different due to (no)availability of suitable tires in 13' sizes.

VeryRed997

Not exactly correct. You can still get the Pirelli CN36 from Lucas Tire. The CN36's are period correct and excellent rubber. BUT at $150 per tire, very expensive. I guess it is all a matter of what you want.

hcaulfield57

iTrader: (1)

Well, either there's something massively wrong with my front suspension or these tires are horrifyingly bad.

Is it normal to have insanely vague inaccurate steering? I know it's not rack and pinion, but these cars reviewed well in period against other rack and pinion cars and plenty of vintage steering box cars are known to have good steering. But this is just bad, there's not even that much play in the steering, but still feels awful. I really don't think I'm expecting too much from the car. There's only 66,000 miles on the car.

Those Pirelli CN36 look cool.

Freeskier7791

For sure it can be the tires, they could be starting to dry rot and the sidewalls are getting flexy. You owe it to yourself to drive/ride in an FB with high performance 15" tires on it.

GSLSEforme

That's one tire & $600.00+ mounting and balancing,one 13" "quality" option. There are several and i mean lots of 15" performance tires of name brands that go for a lot less than that,like $50 apiece cheaper. A 15" tire/rim combo still looks period correct,50 series sidewall are shorter stiffer,more responsive without being harsh like 16-17" inch wheels with 40-45 series profile and(in my opinion) do not look period correct on car. If keeping the RX indefinitely,the most cost effective solution is to upgrade wheels/tires now,(good)13" tires are scarce now,so are 14" tires for that matter. After springing $600+ for the (good)13" tires...when they wear out,the selection for replacements will not be any better and those(good) tires may not be available-in this country. Keep the current tire/oe wheels for the car shows and to put back on the car during winter months and storage. Win,win,win...

GSLSEforme

Certain op tires are not dry rotted,he's replaced them fairly recently. Your idea for him to drive another sorted FB is a good one and would open his eyes and make him a believer. Better yet,maybe another forum member in the area would let him swap their better tires/wheels onto HIS car for enlightment test drive.

GSLSEforme

OP,did you ever radius the body for clearance after installing the larger front swaybar? I recall initially you had not and wonder if swaybar/body contact could be adding to steering woes,sort of like not cutting rear bumpstops can cause rear suspension to have hiccups over bumps/bottoming on axle housing.

Freeskier7791

I forgot that they were new, and that is a great idea, If I was in the area I would definitely let him borrow my set for an hour and see what he thinks. Also good point on the swaybar in the front.

mustanghammer

iTrader: (3)

Bad Tires....My new 2017 Mustang GT has Pirelli PZero Nero AS tires and so did the 2012 Mustang I bought new in 2013. Crappy tires. They follow every groove in the highway and typically start cupping at around 10K miles. So yes, crappy tires are made all of the time and sometimes the OEMs keep using them. Weird

Tires can contribute to wander (see above) but so can your car's alignment. You need to have it checked and you also need to make sure that all of the tie rod ends (inner and outer) are tight. Also check the idler arm bushing at the chassis - these get loose. Basically - check everything, mileage is not the issue, age is.

Back to tires and more specifically wheels and wheel width. If you put the current tires you have now on wider wheels, they will work better. They may still not be that great but they will be better. Over 30 years of racing and autocrossing I have messed around with placing tires of a given size on wider wheels. In every instance, the tires worked better and the car got faster as the wheel got wider. I am not advocating the "Stance Approach" to stretching narrow tires on to really wide wheels because that is stupid. However, it would be interesting to see how your current tires would work on some 13x7's. This is, by the way, the other reason to move to 15's. A wider wheel!

As we have discussed, your tire selection options are very limited in 13" sizes. I would also argue that installing Pirelli CN36s or any other new version of a "vintage" performance tire is a bad idea. Those tires were good, maybe even great, when your car was new. But now, well I would bet the tires you have now may be better.

Here is my last bit of input. Modern cars are better, faster, etc because of modern tires and modern tire technology. It isn't the other way around. Race engineers and builders have long known how to make a car fast....study the history of motorsports. But today, race cars go as fast or faster than they have ever gone with smaller engines and less horse power. Why? Because tires!

Okay that was my second to last bit of input....this is my last. If you take the plunge and update the rolling stock on your car, you need to be prepared to make more updates to your suspension. Remember the 2012 Mustang I mentioned above? When the Pirellis died I installed Continental DWs in the OEM size. The car did not drive better. It drove worse. To get the car to realize the potential of the Conti's I had to put on Boss 302 front springs and struts and a set of Koni sport shocks on the rear. Then the car could use the tires and it became truly superb on the street (lots better than my new car!). My point is that this will be an evolution and you have to think of the car as a complete package. If you do the work, the end result will make you want to throw rocks at you Honda.....

hcaulfield57

iTrader: (1)

Lots of good information in here. Thanks guys.

Definitely a good idea to try driving a well-sorted RX-7. My fear is just that it's driving normally and there's nothing to be improved upon. Since these cars were well received by the motoring press when new, I can't imagine this is the case, but who knows. I don't see how the steering box would be heavily worn at such a low mileage. My father and I rebuilt a 60's Alfa Romeo steering box with at least 90,000 miles (probably 190,000) and it had basically no wear. Turning it by hand there's zero play in the steering box (yet to drive the car though). I don't see how a newer 70's design would be any worse.

Yes, I did trim the frame-rail so that the front swaybar wouldn't rub. It doesn't rub anymore. That was about when I started having handling problems with the car. The Federal 595's I had on the car at the time were an okay tire, but I think at 205 width it was just too much tire for the small stock wheels. I remember being able to move the car back and forth while at a stop just like on my current tires. If it's that easy to shake the car around by pushing on it, I can't see how I wouldn't feel that during even normal street cornering. My current tires are new, I can't see anything being wrong with them (aside from being a crap tire).

I do agree that a 15"x7" wheel would be the way to go. Personally I strongly prefer the look of a 13"x7", but tire choice is limited. I've had the car for about 2 years now, and I do really like the car. I want to keep it. But if I can't get it handling how I want it to, I will sell it to try something else. I like a lot of other cars too.

The comparison to my Civic was in no way supposed to demean the RX-7. My Civic is a very nice handling car. As mustanghammer talked about, it was upgraded as a system. Everything was thought through ahead of time, rather than just randomly thrown together as in my RX-7. The car was bought as a reliable daily driver (ironically my RX-7 has been far more reliable due to lower mileage), and to get into autocross with (it's simply easier to upgrade). My RX-7 was kept as a fun car. The RX-7 has a vastly more interesting engine, far more character and charm, etc.

GSLSEforme

hcaufield,your statement about1/2" of wheel play at rest sounds about right,the 1-1/2" of play speaks to several things.Loose parts,particularly steering linkage can be the culprit. How are you checking steering parts? Let me suggest a process-need 2 people. Drive car into garage,wherever you can park car in straight stop. Have person #2 move the steering wheel back and forth slowly while they watch left front tire. Move wheel just enough back and forth to see tire move slightly left and right. You lay down on ground alongside car and reach in behind tire and put your hand on tie rod knuckle connection while person #2 moves steering wheel as described. This will allow you to feel movement of ball joint AND any play.Do the same for inner tie rod/centerlink,same for pitman arm/centerlink to check for play. Move to other side and repeat,checking tie rod assemblies,idler arm/centerlink connection and last put your hand on body/bracket of idler arm and feel for deflection/play/movement of arm and its bushings. This method makes use of weight of car loading suspension at normal ride height and the resistance of the tires loads the steering parts to expose any play. Much easier to feel for play that you sometimes can't see. You want 0 play in all these parts. Don't assume ball joints are ok,check them also,though with low miles of car they SHOULD be good. Strut rod bushings,if original,replace,poly is best. Check to be sure the steering box to frame bolts are tight,there is a torque spec for them. Have seen this on a couple 1st gens chasing loose steering issues,not loose enough to make noise but enough so to let box move around. Last,recommend if you haven't done so already,ditch oe idler and install a Moog unit,beefy,greasable,never wear out in life of car,has 0 play and never will. Every 1st gen i've put these on the results were quite noticeable. Whatever you find loose,replace. Front strut top orientation,inward and rearward both sides. Gives you max negative camber and most caster. I personally like more caster for better steering wheel return and can be adjusted on alignment rack by using adjust/locknuts at front of strutrod. A GOOD alignment is the final part of equation along with tire/wheel upgrade and adjusting shocks. At this point your car will be as it should be. Post your current alignment specs if you have the before/after readout. Post back results of your suspension shakedown.

GSLSEforme

This website!!! What i write,the way paragraphs are constructed,when posted,it all runs together. Going to try different browser next posting...

hcaulfield57

iTrader: (1)

I'm definitely going to go through the entire front suspension, thanks for the method described GSLSEforme.

I've suspected something could be awry in the front suspension, but it seems odd to me. Since I purchased the car I replaced the entire steering linkage (including Moog idler arm) and replaced tension rod / lower control arm bushings with polyurethane. The car also has new ball-joints (installed via new OEM arms). In theory everything should be okay.

There have been a few days since starting this thread where the handling felt really good to me. On those days I had the usual 1/2" of play in the steering at rest, and basically no play once the car was moving. But when it feels bad the amount of play increases dramatically and basically the steering just feels like it wants to slop one direction of the other and just doesn't feel sharp with very little feel. It's hard to tell how much the front wheels have moved. I feel that the vague steering is either just how these cars are or that it's probably the tires like you all have said. The fact that it's good one day and not the other leads me to believe it's the latter.

GSLSEforme

Other than Moog idler arm,what brand parts did you use for steering linkage,pitman arm? Check it all for play,if all Moog parts(with grease fittings) did you grease all joints on install? They only have enough lubrication in them for construction on assembly line and need to be greased to work properly. Check steering box bolts. When last was car aligned,front wheel bearings checked? Never driven a car that was fine one day and not the next without finding the cause for it. If after thoroughly checking over and all is good,swap on another set of tires/wheels,preferably right after you come back from driving it when it feels "sloppy".

hcaulfield57

iTrader: (1)

The inner and outer tie-rods are Moog as well, the pitman arm is some no-name brand. I have the original pitman arm, I didn't notice any play in it originally, but ended up replacing it anyways. I did grease the joints after the install.

The car was aligned last year on 205/60-13 tires, so I assume the alignment is a bit off due to the difference in tire diameter. Haven't checked the wheel-bearings in awhile, I did them when I first got the car. Unfortunately I'm daily driving the car right now due to problems with my other car, so it will be a few days until I can check all this.

VeryRed997

I took quick note of your comment on the Federal 595 tires. 205/60x14 may be even tougher to find good rubber than 185/70x13. That is why I was looking at the 595. I just looked at them a bit deeper and discovered that they move from a performance UTQG rating (240) to that of a highway tire (460) as soon as you move to any 60 series size. DANG I hate that!

For me that will mean finding a way to 15" rims as soon as I can.

RGHTBrainDesign

Feel free to dip your toe into something that I've done.


The V-Mount is being installed right now, driving by Late June is the goal. LOTS of Wiring to go through.