Gktech R32 Gtr/z32 Front Upper Control Arms

[NISR32.5]

they are out on their website!

Cheers mate. I checked end of last month and nothing.

Looks like a totally different design. I'll be grabbing a set

[GUWOP]

I'm at the put-it-back-together stage and finally got to install mine. They're pretty sweet! 

 

 

 

 

[GTSBoy]

On 8/11/2017 at 7:50 PM, GUWOP said:

I'm at the put-it-back-together stage and finally got to install mine. They're pretty sweet! 

 

 

 

 

Mine arrived while I was on a recent OS trip.  Have ripped them apart with glee today!

Question is....there's a pair of washers in a small bag.  Should it be obvious to me where they go?

[GTSBoy]

Following up on this for posterity.

I finally got back into the country & found enough time to fit the GKTech front upper control arms.  These replaced factory arms that had polyurethane bushes @ inner end and polyurethane bushes with eccentric adjusters at the outer ends - the standard Whiteline/Superpro setup. These had been replaced several times over the last 15 years or so since originally installed, but not looked at too closely in the last few years.  They were comprehensively f**ked.  Bush distortion at each end was so severe that the inner end bolt and outer end bolt were at least 10mm out of parallel!

I put the new FUCAs on, set to factory length (~180mm between bolt centres) as my best guess.  Did not and have not yet gotten a wheel alignment to see where everything is.  Will come back to that point.

So, the car clearly had a compromised front end, not stock, not better than stock.  The GKTech FUCAs are a massive improvement.

• The first thing I noticed is that at very low speeds under certain turning conditions (such as driving forwards out of my driveway), a scrubbing noise/feeling that I was getting for the longest time was now gone.  So long term suspected suspension geometry wrongness confirmed, and now banished.
• The next thing I noticed is that there is a substantial increase in front end grip.  Years of nagging wonder about why the car has a basic understeer characteristic, despite having lots of good money spent on many parts of the suspension, completely explained by replacing twisted crap with straight good stuff.
• No noticeable increase in NVH.  Probably should have expected this, at least until some wear turns up in the rod ends & bearings on these arms.  And especially compared to the creaky/squeaky nature of the urethane bushes, even with grease nipples added.
• Suspension compliance seems at least as good as before.  Placebo effect makes me think it feels better than before, but there's not really a lot to suggest that the old bushes put up any additional resistance over the 5+kg front springs.

On the subject of alignment - my guess of putting them in at stock length seems fine for the moment.  I appear to have >1° -ve camber, but not a lot more than that.  It seems even both sides.  The toe might have been altered from what it was before, because the top end of the upright is now in a completely different place (fore-aft) than it was before with the rooted poly bushes.  Nevertheless, the car drives straight and the steering wheel is straight.  My tyres are >75% worn, so I will watch how they wear before deciding what to do about alignment going forwards.

I probably should mention that I have adjustable caster rods on the front that put a lot of tension into the upper arm's bushes and probably contribute to their getting stuffed.  This same tension is what I think makes the suspension less compliant than it should be (with normal upper arms, not the twisty GKTech ones), and what leads me to expect the suspension to work better now.

Cliff's notes: 2 thumbs up.

Edited December 15, 2017 by GTSBoy
Additional info

[sneakey pete]

Put mine in back in Jan. 

Was already running -2.5ish negative with hardrace arms which have a bearing instead of a bushing and are length adjustable instead of offset bushings, which probably is a better option. That being said the bearings seemed worse for wear (grease coming out) Also would have weird steering feedback at limits of travel, hitting bumps etc on lower speed corner.

New arms in Seem just as good, was a pain to tighten them without having the right sized large spanners but got it to an alignment shop, similar alignment and they seem just as good on the track as the GKtech and much less unpredictable on the bumpy roads. 
Not as much of a noticeable improvement as above but that's probably because the existing arms were serviceable.

[GTSBoy]

Following up on this AGAIN for more posterity.

After 6 months and not very many road kilometers, the "self-lubricating" teflon lined bearings started talking.  And they rapidly got a lot worse.  Over a distance of probably only 500km a little squawk turned into a major cacophony.

The weather has been almost exclusively dry too, so it's not as if they got all wet every day and rusted.

Took them apart and found that the outer rod end on the strong arm part was very tight and marked where it had been galling the outer race.  The other two rod ends on the other part of the arm were also a little tight and a little marked, but not as bad.  The bearings installed in the inner end of the strong arm appear to be COM10T press in rod ends (2 off) with an ally crush tube in between.  A reasonable enough idea, except that these are rods ends just like the others, but don't get any weather/dust protection.  So while the other rods ends have boots that do at least something, the COM10Ts are exposed.  These bearings were all much harder to rotate than they were when new.  I'm thinking that maybe some sort of rolling element bearing with grease seals might be worth considering on these.

So I cleaned everything as well as I could, sprayed teflon spray into the COM10Ts, whacked a lot of lithium grease into the other rod ends and they're silent again.  This may not be the right thing to do, but we'll find out, won't we.

[GTSBoy]

and again.........

GK-Tech sent me a new main body for the one with stuck sphericals.  Very nice of them to do so.

[Duncan]

8 months use, right  Good to hear they replaced them. Do you have the some problem developing on the other side?

[GTSBoy]

I had to grease all the rod ends on both sides.  This is explicitly against their advice...but we all know that people who really use rod ends on race cars keep them lubed.  The sphericals in the main body on the other side of the car are still moving freely enough at this stage.

It's about 8 months now, but when the bearings got tight enough to upset me was a couple months ago.  Only about 4000km of use up to that point, I think.  I can't fault their service.

[GTSBoy]

And  one more follow up.

I still had a lot of noise in the front LHS.  This had previously only ever occurred when the old poly bushes were dry and when the rod ends in the GKTechs were buggered (as described above).  I bought a bunch of new rod ends and changed them all out.  Still noisy.  So many rod ends on a single arm that it is hard to be 100% sure about where the noise is coming from, so I bit the bullet and bought a set of the UAS arms (the old centre pivot ones that they came up with >10 years ago), on a group buy advertised on here to get a batch made up.

Still noisy.  The noise must be coming from somewhere else in the LHS suspension.  Could be the upright's upper bearing, as that is a likely candidate.  But really it could also be in the rod end on the front of the caster rod, or in the lower control arm bush, ball joint, ARB link (which are sufficiently new that it shouldn't be them) or even somewhere unexpected like the crossmember attachment to the chassis.  May have to do a little extra swappsies and maybe invest in some chassis ears.

Anyway, the moral of the story is that I still think the GKTech arms are a good thing and they don't have as much trouble with generating clinking noises as I had thought they did.  Subject to my greasing efforts, anyway.

Edited March 25, 2019 by GTSBoy

[GTSBoy]

And a year down the track, another follow up.

The UAS arms have not done well. They work, when new. But after 10000km of daily driving they have "stretched" so that the centre pivot that provides the equivalent flexibility of the GK-Tech arms now allows the arms to bend (instead of just twist) at their centre point. The amount of sloppy motion that this permits in the suspension is just gross. The car was really quite scary to drive. Very vague, as you'd expect.

So, the GK-Tech arms went back on yesterday. As soon as they were bolted up you could tell that the suspension upright's movement was being controlled properly. No wild wiggly slop. First drive this morning - much better. Clearly the UAS arms were allowing quite a lot of random upright twisting, which affected toe angles and camber in the middle of every load change.

So, my vote's still with the GK-Tech arms, by quite a long way. Even when they suffer some wear in a rod end they won't allow as much slop.

[Torque Curve]

it seems that replacing the bearings with a higher quality is a good start. Aurora Bearings ( http://www.aurorabearing.com/index.html ) seem to be a go-to for a heap of race teams and some distributors in the US are starting to offer the arms with the Bearings updated from new. 

[DaymoR32]

On 5/11/2020 at 10:02 AM, GTSBoy said:

And a year down the track, another follow up.

The UAS arms have not done well. They work, when new. But after 10000km of daily driving they have "stretched" so that the centre pivot that provides the equivalent flexibility of the GK-Tech arms now allows the arms to bend (instead of just twist) at their centre point. The amount of sloppy motion that this permits in the suspension is just gross. The car was really quite scary to drive. Very vague, as you'd expect.

So, the GK-Tech arms went back on yesterday. As soon as they were bolted up you could tell that the suspension upright's movement was being controlled properly. No wild wiggly slop. First drive this morning - much better. Clearly the UAS arms were allowing quite a lot of random upright twisting, which affected toe angles and camber in the middle of every load change.

So, my vote's still with the GK-Tech arms, by quite a long way. Even when they suffer some wear in a rod end they won't allow as much slop.

sorry to drag up an old thread. im looking at purchasing some of these shortly. 

Do your comments still hold up or has your opinion changed on these?

[GTSBoy]

Nothing's changed. It has been another ~8000km since the previous update. Haven't even looked at the GK-Tech arms since that post (ie, no problems that would cause me to look). UAS arms have been in the bottom of a box in the shed since then and I anticipate that they will never go back on the car.

The GK-Tech arms are good. I did have some concerns with them to start with, as described in my earlier posts. Nothing that was not overcome. I made up some nappies to go around them, from clear PVC sheet and press studs. This to keep the dirt and water away from them as much as possible, so I can have lots of grease in the boots. The effort seems justified. Keeping in mind that this is 100% a daily road car and I would rather do something else on weekends than jack up the car, dismantle the front suspension and clean and lube "race only" FUCAs.

[Butters]

Sooo I bought these after recommendations on threads like these. 

The joint snapped at the shaft, light driving, straight line at 50kmh.

Had been in car 6months, no track days. 

 

Contacted GKTech and they are sending me a "more robust bearing". Which is now on all the arms. 

 

Not sure if I am going to use them or switch to rubber bush, mine is a street car so i may have gone to far going with these. 

 

[GTSBoy]

27 minutes ago, Butters said:

The joint snapped at the shaft, light driving, straight line at 50kmh.

Seriously, there is far better than even odds that this was your own fault. Not attacking you, as it is very very easy to set these up wrong. If you don't keep the spherical joints close to the centre of their range of motion when the suspension is in the normal position, then they can reach the end of travel just with normal suspension movement and then they stop being a pivoting joint and immediately become a rigid connection. This puts all the force that would have made the suspension go up-down (or whatever direction it's supposed to go on that joint) go into the spherical joint's thread and it only takes a few of these bumps to snap them. I managed to flog out a couple of spherical joints (but not break them) by not having them sufficiently centred. it's really hard to make sure that all 3 sphericals in the GK-Techs are centred, especially when they are in their boots and doubly especially when there is grease on them.

31 minutes ago, Butters said:

Contacted GKTech and they are sending me a "more robust bearing".

They are good like this.

31 minutes ago, Butters said:

Which is now on all the arms.

Which bearing was it? I'm assuming (per my long paragraph above) that it was one of the separate sphericals, not the pair of captive ones in the main part of the arm.

[Butters]

I installed, video instructions followed and made sure it was nice and free as per instructions.  

No signs of binding and you can see it was running centre on. 

Well until it failed of course  

 

Your comment is out of line on who's fault this is. 

If a small setup issue is going to result in such catastrophic failure that could have easily resulted in a vehicle crash. 

The company of the product needs to REALLY step up on the level of warnings and instructions. 

If this is a failure from a as you state, easy to make setup issue I am also surprised I found no more examples of it when looking to buy. I can tell you, had I, I would have gone with a bush kit. 

 

*awaits to hear how picture proves it was setup wrong .....

 

[DaymoR32]

20 hours ago, GTSBoy said:

Nothing's changed. It has been another ~8000km since the previous update. Haven't even looked at the GK-Tech arms since that post (ie, no problems that would cause me to look). UAS arms have been in the bottom of a box in the shed since then and I anticipate that they will never go back on the car.

The GK-Tech arms are good. I did have some concerns with them to start with, as described in my earlier posts. Nothing that was not overcome. I made up some nappies to go around them, from clear PVC sheet and press studs. This to keep the dirt and water away from them as much as possible, so I can have lots of grease in the boots. The effort seems justified. Keeping in mind that this is 100% a daily road car and I would rather do something else on weekends than jack up the car, dismantle the front suspension and clean and lube "race only" FUCAs.

perfect, will get some ordered ASAP!

[GTSBoy]

9 hours ago, Butters said:

*awaits to hear how picture proves it was setup wrong .....

Given that that  looks like a torsional fracture plane I can see exactly how that would demonstrate the failure mode I described. The outer ring of the bearing has clearly been twisted off of the rod.

Perhaps get off your high horse and accept that it could have been your fault.

9 hours ago, Butters said:

The company of the product needs to REALLY step up on the level of warnings and instructions.

Also, keep in mind that you're not supposed to use these on the road and that it is intended that skilled and experienced race mechanics/engineers set them up. That's people who already know the risks of what happens when these joints reach end of travel.

Caveat emptor has never been so meaningful.

[Butters]

Just see it from my point, the simple fact I am typing the next list is suggests your focus is on the wrong outcome.

I have no issue to accept that it may be setup wrong, by me and it resulted in this failure.

Your assumption that I am a numpty is the problem.

 

> Researched options and spoke to people that own them

> Spoke to GKTech about my intended purpose being road use.

> Installed, followed instructions

> Had professional suspension place(road and race) go over all suspension prior to engineering.

> Engineer reviewed all suspension, photographed, signed off and submitted to DOT (yes inc camber arms)

> DOT carried out a full inspection of vehicle, again including these arms.

 

Driving normal road ... *Snap.

 

Throughout all this process not a single mechanic, engineer or inspector saw an issue.

As I said, they could have been setup wrong, yes I might have done it(I don't think so).  The suspension place was explicitly asked to check.

If it had bound on setup, i would have also expect it to fail closer to install, not 6 months later.

It would suggest more likely to me a regular checking of product is required, the product is not suitable for road use(even with engineering) or a fault of the product has occurred here.

 

It is from what I see an unusual event, so if you are correct it is a setup issue, then it is a really good learning for others that should be shared.

 

 

 

 

Edited June 24, 2021 by Butters