Requesting feedback: Z1 forged FUCAs

[FSUZ33]

Got them yesterday (street bushings). Waiting on Ohlins coils for install (month?). I'd appreciate feedback from those who are running, or have run these.

Here and elsewhere you can find buzz, good and bad, about Z1 and their suspension components. It looks like they have had serious issues with their tubular FUCAs, and I'm curious if that crosses over to the forged parts.

The forged set has sleeved connections like the SPL/NISMO, which tells me they are adjustable on-car, but I'd like that confirmed.

My M.O. is I'd prefer bushed rather than solid/heim joints. But I don't have experience with heim joints, cheap or high quality. My backup to the forged Z1 is SPL or NISMO, which are almost twice the price of the Z1, and only come with heim joints. If the forged arms sitting here in my office are duds, or are likely to become duds, I'd prefer to return them now and go with SPL/NISMO. I only want to do this once (doing it myself) so feedback is greatly appreciated.

I know, I know; this thread doesn't belong here. But this forum gets attention and I need to make a quick and informed decision.

 

[TexasZee]

I'm going with the SPL/Nismo suspension set up soon. I was going NISMO from the get-go to be quite honest, but with the past Z1 FUCA issues and comments you can find online, I wouldn't spend my money on them. I purchased their engine cover and even that had QC issues out of box. I can understand your concerns. Buy once cry once type of thing imo. Best of luck on the build.

 

[Drago86]

I was wondering the exact same thing.

I did find this video that is only mildly concerning:




I was looking at these also ,possibly, as an alternative to the pricey SPL\Nismo(made by spl) arms. For the SPL's, I don't like that the ball joints don't have rubber boots as I feel like ball joint's/ heim joints should always bee booted on street cars to reduce wear.


The Z1's LOOK like a nice piece of kit, and every thing is dust booted ,which I like, but a few things concern me:

1. I ,like most rational people, trust SPL a HELL of a lot more than I trust Z1 when it comes to things like this; but lets give them the benefit of the doubt, maybe these arms are the start of their redemption arc.

2. The grease zerk in the top of the arm looks like it will hit on a very lowered car and/or extreme suspension travel. You can test this when dry fitting them, I was thinking of possibly replacing the zerk's with an allen grub screw if i got them and this was an issue.

3. They do not include offset spacers like SPL does for the heim joints to allow extra castor adjustment without tilting the arms(though they do claim to have 7.5 degrees of bult in castor).

4. The way the side adjusters are cantilevered a little on the sides of the arms gives me a bit of the heebie-jeebies compared to the SPL arms

5. The above video mentions the ball joint being extremely stiff,.. which they shouldn't be,.. and also mentions that the ball joint shank is hard to insert into the upright,.. which it shouldn't be,.... If they messed up something as simple as the ball joint shank diameter, or their ball joint supplier cant hold the proper tolerance,... both are equally concerning.



Things I like about the arms:

1. Forged aluminum.

2. Cheaper than SPL

3. Adjustable on the car

4. Looks to use a real automotive ball joint of decent size (hopefully it isn't oversees junk, but if it is it's looks easily replaceable ,just like the heims, with a more quality piece)

5. Dust boots on all joints

6. They claim to have done FEA and actual engineering designing these.


I too would like to hear form someone who has tried these out. I would LOVE it if these were as good as they look like they could potentially be......


Rant:
I've learned not to fully trust Z1 on things that require actual engineering. For example: their braces, many of which would end up less stiff than stock and often don't seem to understand the assignment. Their W brace and the high clearance rear chassis brace for example; The factor W brace has vertical ribbing:

Showing that Nissan was concerned about this brace's stiffness in the horizontal AND vertical axis, like an I beam. The Z1 brace uses flattened aluminum tubing in a design that looks like is intended to be stiff only in the horizontal direction, ignoring the vertical and ending up significantly less stiff than stock in that direction.

A similar problem exists with the high clearance rear brace, using the same size tubing in aluminum results in ~2/3rds less stiff brace(aluminum vs steel young's modulus) and they incorrectly state that the "Solid aluminum bar maintains rigidity" Which is false, the rigidity to bending is primarily driven by the OD of the bar/tube, while strength is driven by the cross sectional area. Nissan increased the OD of this brace on the Nismo by welding square tubing around it, so they were obviously interested in stiffening this brace and not just it's strength. Additionally adding extra bends allows the brace to flex easier/ wing/ unwind the bends like a spring.

I hate to bash on Z1 because they are one of the few companies that makes cool stuff specifically for our car but I really really wish they would improve. Hire an engineering consultant to run things by before you release them as products.

Having an aluminum W brace that took into account stiffness in both planes would be super cool and I'm upset it doesn't exist. Likewise having an stiffer aluminum rear chassis brace with larger diameter tubing would also be super cool. I'm mad these thing don't exist and more research wasn't done before pumping out products.

The braces are just one example that particularly irritates me but, there have been lots of instances and forum reports of failures in either quality or fundamental engineering in their house products over the years. I hope they are improving.

/Rant

 

[alienpoker]

I’m not that technical with suspension parts, but I do know that Z1 has sourced stuff made cheaper & then sells it as a kit. My dad explained it as: “There’s always someone willing to make an inferior product and sell it for less”.

So I’d buy the original manufacturer’s part vs Z1’s cloned version of the same thing. Even if it cost me more. If it’s Nismo branded (or you know the brand) then they’re fine. I’ve used Z1 for years now and they are honest about their parts if you can ask the right questions. Where it’s made, what actual testing they’ve done…