https://www.spcalignment.com/index.p...tion&pid=25002 the upper control arm are pretty much an adapter for their ball joints. seems sealed metal to metal, but that may also be what we have stock.

The ball joint should not be the problem. The bushing itself is what may potentially be the problem. SPC's more expensive arms have a rubber/spherical hybrid for their bushings which I don't think is legal since metal content is increased and bushing material is decreased. I think they mainly used this because the entire arm articulates. So, without a spherical bushing, it would put a lot of stress on the bushing if you adjusted away from it's true neutral position. But, since the there is no adjustment to the arm itself on the cheaper arm, they can probably use a regular style bushing, either rubber or poly. I've looked at more pictures of them I've found on the interwebs and they appear like they're legal. I may switch to these arms.

The original design SPC FUCA's have a standard poly bushing on the chassis side and are legal. These are what I have on my BSP car.

Did you need to modify them to hold settings? I remember that being an issue with them when I first started researching these cars. Also curious about how much camber/castor you can get out of them.

I had the old SPC arm and didn't have issue of it slipping.

I think from the time I put them on in 2015 till now, I've had one arm slip once and it wasn't even that much (~0.5°).

Regarding how much camber you can get, from what I remember with the adjustment all the way inward it was around 4-4.5° which is more that I've ever needed.

That is good to know. What do you think was the cause of the slip?

Probably just not tightened enough combined with Hoosier grip. Basically, tighten them nice and tight and then tighten them even more.

Good to know. The z1 arms are working ok for now, but if I notice anything weird it's good to know there is an option.

First event with the new car is this weekend. The changes from this car to the old one are:

*18k springs up front
*the old 13k that were in front are now out back
*the car sits closer to 27" all around - old car was slightly under 27"
*corner balance is nearly perfect 50% cross weight - experience using scales and less concern over the car not being visibly even on all 4 corners when hard parked
*super sexy turn down exhaust tip

I'm most excited about the new front springs. The old set-up felt nice but the car needed more roll resistance, especially on grippy concrete. My only concern would be additional understeer mid corner but I can always throw the rear sway back on if it comes down to that.

I'm also hoping to have wheels by nationals which should be fun. Thinking about trying out the advans in 275/40r18.

You can try a G37 rear bar if the stock rear bar is too stiff for you. My last event in the car was with 1100/850 and it felt pushy still.

Just don't run a rear bar.

^^^Agreed!

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I ran with my rear bar disconnected for the first time last weekend. I didn't enjoy the understeer on corner entry, but I did love the additional traction out of the turns. I'll likely remove it completely before the next event.

link and video to my ftd.

Car drove well with the stiffer springs up front. I was happy I didn't forget what I learned in Lincoln before the first car got smashed. I took second to my buddy Kai who won spring nats in his e46 m3. The delta is getting smaller but my driving and the car will need some work before I can challenge him directly.

Understeer on slow speed entry is the biggest thing I notice without the rear bar but it just makes sense on the faster style courses we get at Nationals. It is tempting to pick up that G37 bar for local events but I don't know if I want to introduce another variable to get used to when I travel.

Like any race car. you have to tune the suspension for the track. What works for one track may not be good for another.