dopsdad

Before I get started on my problem, I know there's no such thing as a convertible Nismo, and now I know I've made some bad decisions that I wouldn't have made if I knew everything I know now. I do custom graphics, I had a look in mind, and I did what I did before I knew some of the unique things about Zs, like the front suspension can't be adjusted. Hopefully, someone can see past all of that and help me with my issue. Having said that....

So, I recently bought a bone stock 04 convertible that came stock with five spoke 18" rims, 245/45r18 tires on rear, 225/45r18 on front. I bought my car for it's reliability, and its looks. Without realizing the front suspension wasn't adjustable, and the front end geometry would be screwed up by different rims and tires, I put some spoilers and graphics on the car, and purchased new rims that I could customize to get a particular look. Here's the rub, the rims I bought were 18", but they are offset 40, and I wanted to go with 245/45r18s all the way around so the tires could be rotated (again, rookie mistake). For appearances, and to make sure the rims would clear the calipers, I used 1" spacers all the way around. Now the car is shredding the inside of the tread on the front tires. at about 1000 miles the inside was significantly worn, so I installed a set of Kinetix upper control arms. I've pushed them out as far as I safely can (ran out of threads on the main post), and I'm still wearing right through the tires. I've installed all new bushings on the lower control arms, so now I'm wondering what else I can do - I'm not even sure buying a set of 225 tires for the front will resolve my issues at this point. I saw that some Zs had 19" rear tires, and 18" front tires, and I'm wondering what parts are different that change the camber (lower control arms, upper control arms, spindles?) Does anyone know what parts I need to change to keep the 245s on the front and stop them from wearing so fast? I really want to keep the customized rims because they are a key element of the car.



Rims Revolution racing R25s
1" spacers
Kinetix upper control arms
Tires 245/45r18's all around
Wear shown is about 1500 miles on brand new tires- this is aggressive wear!

Any help is much appreciated.

travlee

iTrader: (8)

Did you get an alignment, wondering what your toe is

MicVelo

First off, what year (and production date if avaIlable) is the car? What's the width of the wheels?

What's interesting is you already have the things you would need to correct the alignment and fitment issues. Wheel spacers to bring that +40 into a better fitting +15 to +25 and adjustable FUCA for camber and toe. Those should easily have enough adjustability to bring the car into correct spec - particularly toe and camber. Has the car been in an accident where the front suspension might've gotten tweaked/bent?

Has it been put on a rack to see where your alignment's at (as Travlee asked)?

GT and Nismo had double stagger 18/19 but that's totally irrelevant as you have other issues with improper camber & toe wearing those tires out so quickly. Early Z33s (2003-2004.5) had severe issues with the front end wearing/cupping the front tires but that was corrected after '04.5 MY. Tire/wheel fit on Z33 is pretty open with enough space for much wider widths F&R so that's telling me your alignment is likely fouled.

As you can see, more questions than help because without that info, pretty tough to render a complete diagnosis. But Trav's right, you probably should take it in for an alignment or at least an inspection. Alignment techs can tell you more about what they find.

dopsdad

As I noted, it was a stock 04 when I bought it. The only changes I did were spoilers and wheels. I read somewhere yesterday the stagger is important to maintain the geometry, and they mentioned that not staggering the tires can also throw off the traction control system. This makes sense to me because I always have to turn my traction control system off, if I leave it on I often get a jerking and hesitation when I accelerate in corners. Until now I thought something was wrong with the traction control system, but now I believe that the lack of stagger is what's causing it. Basically I just wanted to know if there are different parts in the front suspension to accommodate the bigger tires used on the front when 19 in wheels are in the rear? I've tried to compare parts online but it looks like the lower control arm upper control arm and spindle are all the same unless I'm missing something. The other important thing to note is that the only reason I change my upper control arms is because this wearing was occurring with the stock control arms. When I installed the kinetix control arms I laid them side by side with the stock version and turn them out an extra quarter inch or so, then adjusted them out to zero camber with a camber level. I know some adjustment had to take place because there was some slight rubbing on the inner fenders that I had to fix, but it didn't fix the tire wear.

stick

travlee

iTrader: (8)

once again.... did you get an alignment?

GreyZ

iTrader: (2)

Why post a photoshopped photo?

Any way, its very likely blown lower control arm bushing and blown compression arm bushing that is causing that wear with toe out when turning or braking. Send a photo of your lca and compression rod bushing. Also if you have bad tire wear and have not had an alignment... GET AN ALIGMENT AND SHARE THE BEFORE AND AFTER DATA. Eye balling the camber yourself is a terrible decision unless you really know what you are doing and even with that, toe is most likely the issue.

MicVelo

OK, does your car only have TCS or does it have VDC? Tire sizes not at the 2.5% to 3.5% F-R delta can trigger VDC and to a lesser degree, TCS due to the ECM getting matching wheel speed readings. The ECM is looking for the 3% difference in wheel speeds between the F & R.

No, there are no differences in suspenson between the lower trims using 17 or 18s and the dual staggered 18/19 setup. The tire diameters are all very close, e.g., a stock rear 235/50-17 (Base wheels) and a 265/35-19 (GT/Nismo) have essentially the same diameter with a non-perceptible .05" difference.

When you say "zero camber", how do you know that if the car isn't on an alignment rack? (Not to mention that a true 0-degs camber is totally wrong and will make the car less stable as the car's suspension geometry is designed for as much as -1.3° factory) As mentioned by GreyZ, above, eyeballing an alignment setting that's so small is next to impossible. Generally speaking, when installing the FUCAs or other suspension components (again, as Grey said, compression arms, etc), the object of DIY on the garage floor is getting them to a driveable setting (eyeballing as you did) IN PREP for eventual alignment immediately following install.

Then there's the possibility that using the OE FUCAs as a baseline for setting the new ones was wrong since the tires were wearing badly with the originals. Whatever the case, there's still no point in further diagnosing or even putting hands on without empirical - or "what are my exact settings right now?" One more time, alignment. Zs are pretty fussy about this.

dopsdad

So GreyZ, you're exactly the kind of guy I was referring to in the beginning, the guy who always needs to find something to pick at to make themselves feel better. That photo was my concept photo before I did the car, I was lazy and didn't want to go out and take a photo for this post, but I did want those who might question my attachment to these rims with the alternate offset to see the contribution they make to the overall look, and why I'm trying to find a way to keep them.

Having said that, if you would have bothered to read the details and not gotten so hung up on the origin of the picture you would have noticed the line, "I've installed all new bushings on the lower control arms."

I'll post a picture of the car after it was done so you can concentrate on the text.

dopsdad

dopsdad

MicVelo, it's an 04.

I have access to a garage (level floor), so I did a four point string alignment with a magnetic camber kit and a blocked level on the hood. After I realized the tires were wearing I took it for a front end alignment and was told only the toe was adjustable. After I put the Kinetix uppers on they didn't want to touch it because it was aftermarket parts. Initially, I laid the Kinetix uppers on the stock uppers and turned them out an extra 1/4", but it wasn't nearly enough. I basically turned them out as far as I safely could, and that put me at about -.02 on both sides. I thought the problem was solved because the steering became super sensitive (darty) and I attributed that to running on the outside edge of the tires. Unfortunately time revealed they are still wearing on the inside.

Thanks for the info, it was super helpful. Now that I know there's no difference in the front suspension parts, and my objective for having four tires the same size to rotate them is a giant fail, I think I'll just throw a new set of stock uppers on and reduce the front tires to 225s to see if that resolves the wear issues. Someone mentioned 03s and 04s have wear issues anyway, so I'm assuming mine probably falls into that category.

dopsdad

Thanks for the info. I did a four point string align with a magnetic camber kit, I couldn't find a shop that would touch it. I posted more above.

travlee

iTrader: (8)

let me ping my buddy who had the kinetix arms, he would adjust them between autox and street, he had it dialed down to how many turn would equal approx camber

GreyZ

iTrader: (2)

The ONLY reason I ask, is because I have seen a ton of these questions with people showing shopped photos and asking questions and in the end it turns out that they weren't telling the full story. It was a one line just wondering the reasoning and making sure we knew the full story before answering. Your car isn't my taste, but it looks nice and well done. I think you did totally right by fitting adequately sized spacers to fit the wheels you like. I did read your comment about replacing the lower bushings, which is why I asked for a photo of those, because I have seen bad installs more times than I can count, or people replacing the LCA bushing with a stock bushing and not touching the Compression rod bushing. Some people don't know the difference and it is easier to help if they include a photo. Photos can also show if you replaced the lower ball joints which you did not mention or the tie rods.

You mention that changing the front tire size changes the geometry, but it absolutely does not affect the alignment or geometry. So I don't want you to throw different tires on this expecting the issue to go away and it does not, because it will not.

I have run a square tire setup for 130k miles. 285/30r18. It will occasionally fuss if I am accelerating hard in a corner with TC on, but otherwise there are no issues. So I think there is something else going on.

I am ALSO running the Kinetix arms just like you, and have for 115k miles. I can help make sure you have everything setup correctly, I just wanted to make sure I understood the situation and photos are typically the easiest method to do that.


The kinetix arms absolutely should not be that far out. Me (and others with the kinetix arms) had to modify them to get MORE camber and run them close to maxed out jsut to get 2 degrees. Running them max extended would me at least an inch more length than the stock arm. I would be interested in a photo just to see what that upper arm looks like. When you installed these did you also have to adjust your toe a SIGNIFICANT amount?? changing the upper arms that much will need a ton of toe correction to get them back in line.
Again tires may help your TC coming on, but it will not do anything for the tire wear.

Few more questions:

From the photo, your car appears to be on lowering springs. Is that the case??
Are you still on the OEM inner and outer tie rods?
What are your alignment numbers? If you did it yourself the inch measurements are fine. They can be converted.
Just to confirm, you replaced the inner LCA bushing, compression rod with new outer ball joint and inner bushing, and outer lca ball joint?

travlee

iTrader: (8)

Talked to my buddy....if they didn't change thread pitch he said it's about .18 degrees per turn

Heel Til I Die

iTrader: (2)

I see you're in VA. Ask around to some fellow enthusiasts or do some research for alignment shops for drivers that take their cars to VIR. They should be able to refer you to a shop that will put it on an actual alignment rack and get you dialed-in with your aftermarket FUCAs.

After I installed a modest drop with some new coils, Bilstein B8s, new bushings, and some Z1 FUCAs, I took it to a specialty alignment shop that prepped cars for VIR even though I live in NC. I was getting similar inner tire wear. They got me dialed in nicely and I have no more uneven tire wear. Personally, I would not trust the string method.

dopsdad

I got the car about a year ago, it was a Carmax trade in, and appeared to be completely stock. I think the larger tires filling the wheel well are giving the appearance of lowering, but to my knowledge everything is factory, including the tie rods. Frankly, I don't remember the exact measurements. I put two long poles on jack stands at the front and rear of the car, I put strings on each side, measured to make sure they were equal distances apart at the front and back, and then measured from the center caps to ensure that the measurements at both front hubs were the same, and both rear hubs were the same. For my to I adjusted on the ground (with two layers of plastic under each front tire) until the measurements at the front and back edge of each rim were equal. I used a tape with metric measurements to be as precise as possible (it just helps me). That was the totality of my toe adjustment. The camber was done with a magnetic camber level and a builders square taped vertically on the front face of the tire.

I put all new bushings on the LCAs, I can't recall if there were two or three per side. The upper ball joints were replaced with the new control arms, and as I recall, I checked the lower ball joints and found no play. If it were a lower ball joint problem it would be a wild coincidence that I'm getting the exact same issue on both sides in exactly the same pattern, so as one who has done this a long time I know my check was good.

I went out to take a photo, but frankly, I just don't have the time. I'm trying to fix my pool for the kids, my deck needs repair, blah blah blah, and since it is too cramped and dark to get a picture with the car on the ground, I'd need to jack it... that's just not going to happen at the moment.

I do appreciate your help, you've provided some valuable information to help me. My Kinetix arms are turned so far out they were bumping the inner fenders and I had to make room for them, so I know something must be off. Also, knowing that you have run a square set up successfully is extremely helpful.

dopsdad

Thanks Travlee, that will be useful,

dopsdad

Thanks Heel. I'm sort of DIY out of necessity, I live on a shoestring budget. I guess I could splurge one time to get it straight, but I just don't want to drop big bucks on an alignment, and specialty shops sound pretty expensive.

Heel Til I Die

iTrader: (2)

I hear you on that. The shop that did my alignment was Automotive Performance & Chassis in Cary. Total cost was about $300. Cheaper than a new set of tires!