Z32 Upright Discussion (coilovers, binding, unsprung weight)

[aa87]

I got a really good deal on an entire z32 rear upright coming with full calipers all around. I really want to put them in because of the weight advantage of losing unsprung weight, but figuring out whether powered by max has a z32 rear perch has been one issue along with a few others.

1. Anybody know any other manufacturers, (megan, Stance) that use the same coilover thread and coilover diameters as the powered by max where I can use the z32 rear coilover mounts on my powered by max coilovers?
2. After seeing issues with bushing movement, as well as potential binding, rubbing of mounts, etc, what are solutions. I see that a high articulation spherical such as what skullworks is selling seems to be a good option, but I havent seen images of what that looks like with a coilover, including clearances the toe arm/upright itself. Spherical is pretty pricey but you have to pay to play.
3. Or with these concerns, should i ditch the upright all together. I will be doing full z32 brakes with the rear ebrake and figure might as well swap the upright on, but im concerned with issues like this, then it may not be the upgrade for me, though i read in one bind thread, one guy removed his after some bad coilover rubbing, but claimed he had a noticeable difference due to the ~8lb reduction in unsprung weight.

Opinions/solutions?

[Sileighty_85]

I have my old bottom mounts off my Stances you can check the size and thread pitch with.

as for the bushing bindage I think thats only an issue with S14's

Heres how mine sit right now

[ManoNegra]

OP - what s-chassis do you have?
S13 will be fine, no binding
S14 will have an issue
friends (and what I plan to do) grind a portion of the
shock mount at an angle to get clearance with the coilover forks

sphericals on an S13 are nice but not a necessity
on an s14 they are IMO
the angle that the coilover with the z32 uprights will lead to binding

another option that I'm contemplating
is taking the z32 to a fabricator and have the shock mount
cut, clocked and welded to correct that misalignment angle

on a note, if it's within your budge to get spherical do so
the difference in articulation is worth it
auto-xers and road racers swear by them
even on stock uprights

[Def]

Spherical bearings in ANY pivot on the rear of our cars is an absolutely huge upgrade. On an S14 with Z32 uprights it's basically a necessity from the high angle. If you run your car very low, you might need to slightly file the upright itself(the angle gets worse with travel), but they're a huge upgrade that you can immediately feel. Think about it, it'd be like going from a 20 lb wheel to a 13 wheel right there - absolutely huge.

Sphericals in all the other suspension pivots just let the suspension move without binding. With spherical bearings you can move the rear suspension up and down with one hand(without the coilover on there of course) - it's that low friction. Try that with rubber bushings, or even worse, polyurethane.

[az_240]

If you have an s14 forget it.... Unless you have a way to cut and correct the angle of the shock mount like the R14.

I had them on my s14... after grinding them down for clearance they would still bind and made my car handle like shit. Even with a spherical in there I believe the angle still messes with handling.

The weight difference is noticable but not a huge deal.

Poly bushings are a nice upgrade if you trim the sides down to keep them from binding when you tighten them and keep them lubed(zerk fittings).



Edit: I take this back... Def is right.... poly bushings are horrible when installed in the uprights because they just create too much friction to let the sleeves rotate when the suspension travels. Might as well keep OEM rubber or go spherical.

[Sileighty_85]

OP's got an S13 so he's GTG

[Def]

Originally Posted by az_240

The weight difference is noticable but not a huge deal.

Poly bushings are a nice upgrade if you trim the sides down to keep them from binding when you tighten them and keep them lubed(zerk fittings).

The weight difference is VERY noticeable. It's more noticeable than dropping 40 lbs off the front of the car(sprung weight).

Poly bushings suck in the upright IMO. No amount of messing with them or lube will ever fix them not wanting to rotate axially as the suspension moves through its travel. They're the worst choice of bushing material for this type of pivot point that has multi-axis rotation.

[az_240]

My poly bushings are pretty solid... more so than stock that is for sure. Trim them and keep them lubed and there shouldnt be any problems.

Sphericals would be nice but for that kind of money I'd rather get something cooler.

[projectRDM]

When I did mine, Tein wouldn't sell Z32 fork mounts so I took a pair of old Z32 shocks and cut them up, then cut the ball mount off my HEs and welded the fork on, but at a slight angle, after setting the ride height and preload. The only issue is I can't change the ride height now without a full turn of the lower mount, but it takes some of the binding away by having it sit tilted a little. Still, the bearing is a much better choice and had they been available a decade ago I would have done them.

[aa87]

Ok, I'm gonna experiment for powered by max coilover users for lower mounts, When I get a chance, i'll try the stances of sileighty 85, if not I've read that potentially some Honda coilover perches may also work, if so, i have a friend with a spare prelude lower perch that i could try.

Thanks for the insight guys, I didn't know it was a difference between s13 and s14 binding issues, so now I'm definitely leaning towards putting them on the car.

[ManoNegra]

Originally Posted by az_240

I had them on my s14... after grinding them down for clearance they would still bind and made my car handle like shit. Even with a spherical in there I believe the angle still messes with handling.

With the stock bushing, yes, it will still bind
the spherical solves it, seen it on a couple of friends cars

Poly bushes felt ok on smooth roads
on mediocre ones, felt like driving on train tracks

[az_240]

^they must have taken a lot off the upright to get it to clear okay... my main issue is still the angle of the shock mount(on s14) which does not change with sphericals... that much angle cannot be good.

I know what you mean when you say driving on train tracks.... my poly bushings were "sandwiched" between the mounting tabs making it very hard for the suspension to travel. Once I trim them so the inner sleeve sticks out more it should help with that problem.

[Tenchuu]

not to bump a dead thread, but for future searchers, you need to remove the metal seal from your 240 axle and keep the rubber ones in the Z32 upright, as well as know that Z32 f(at least stance) are about 3/4 in shorter than S14 end cups, so you loose that ability to keep your car at a decent height for 255 to 285 wide tires.

[fmrogers]

Zombie thread! Does anyone know if the megan racing Z32 coilover sleeves (MR-Z32RM) have the same thread pitch as tein Mono-flex?

[G-E@Z31P]

How about I un-zombie this thread with something I've been working on for my racecar?

S-chassis rear coilovers on Z32 upright, with a cheap little adapter kit sound good?





Not pictured, there's a slug that gets installed instead of the bushing with 2 holes in it, you then bolt the black bracket onto that, and then bolt in the S-chassis strut bottom into that... aligning the directions of everything is also super simple, and the slug can be installed backwards to adjust the strut position as needed

Most of the solutions I've seen for this involve making either a custom fork for the coilover, or cutting and welding the cast aluminum mount, which introduces it's own problems

I am aware that some S13's are slamming their suspension to a point where every last thread counts, and with this adapter you will lose about 40-45mm of maximum slammage, so it will be up to you to figure out if your setup can accommodate it... S14 or subframe swapped Z31's shouldn't have any issues

The axis of the slug needs to match the strut axis at ride height when looking from the front, the strut can then be attached to the upper tabs by through bolt, which gets tightened at ride height (just like any bushing)

I did investigate making a bracket that mounts the strut in various directions around the Z32 upright's bushing pod, and in every case, there was interference or weakness, this seemed to be the only sensible way

The bracket is 1045 steel, e-coated, the slug will be anodized aluminum, with all zinc plated fasteners and locknuts... the bracket weights about 280 grams, I expect the total kit will add around .5KG to each corner

The additional weight is easily offset for most coilovers, because the z32 fork style bottoms are generally steel, at least the ones you are likely to have modified, whereas the S13 style bottoms are aluminum... after saving ~8lbs according to some threads going with the aluminum upright, you might actually turn out weight neutral

[onehundredoctane]

Very interesting fix, how far are hyou from a finished product?

[G-E@Z31P]

About a week ?

[onehundredoctane]

I'm interested to see the finished product installed!

[cured13]

definitely interested

[G-E@Z31P]

Everything arrived, fairly painless install, used a flapper wheel on a dremel to clean out the hole, after cutting out the bushing, sprayed with wd40, used a long m10 screw with big washers to draw it in against a cross bar with a hole in it...

Then I just leaned on the bracket to line it up, and rammed the bolts through, voila!

[onehundredoctane]

Very cool! How much for this adapter?

[G-E@Z31P]

Ok I have a bunch in stock now, cost creeped up a bit, but still not bad... $85+ship

[az_240]

Any pics on the car?

[G-E@Z31P]

Not yet, my car has been shuffled through 3 different shops, and it's annoyingly far away now ...

[WOOTEN]

Ok, I got that the S14 has binding issues, and the S13 dont... buuutttt, what if your S13 has an S14 rear subframe?

Also, Im in need of those adapters... anybody use them yet?

[eek]

Very Interesting... Waiting for more pix and a update.

[WOOTEN]

I talked him tonight, I will be ordering a set at the end of the month.

[NismoPlsr]

Originally Posted by WOOTEN

Ok, I got that the S14 has binding issues, and the S13 dont... buuutttt, what if your S13 has an S14 rear subframe?

Also, Im in need of those adapters... anybody use them yet?

The binding issue is due to the strut angle which is mostly just chassis dependent not subframe, so you should be fine.

[WOOTEN]

Sweet! This should be epic!

[nextproject]

Any update on these? been seriously considering the Z32 rear uprights as one of those "something to do" projects while i save for the engine swap.