Shift9303

Hey all, was wondering if any one has experience with front upper control arms from K Tuned/Megan/P2M and similar? Yesterday I test mounted my Apex 17x10+48 wheels and as I feared they are too aggressive. Looks like I joined the hellaflush club and got bags.



I am currently running -3.5* camber and based off my spit ball data it's just about right for my setup; also I'm pretty sure my adjusters are maxed out too. I'm aware of offset bushings however I came across these control arms and in my mind additional adjustability would be nice. It also wouldn't hurt to have fresh spindle joints too. However in particular I am concerned regarding how the sliding adjustment of the ball joint plate does not appear have any indexing points across all of these designs. I would be concerned about settings walking out on me. Leaving the plate at max inward adjustment likely would be secure as the plate would butt up against the edge of the adjustment slot however based on photos max inward adjustment likely would be too far for my needs and I would like leave to have the plate somewhere in the middle of it's adjustment area. Does anyone have experience with these control arms and how well they hold settings? Is there an easy way to manufacture some sort of spacer to help them hold position?

I am also aware of front upper control arms from Ikeya and Origin Fab which have better adjustment security however they are much more expensive. For my budget the arms from K Tuned and the like are similar enough in price to offset bushings that I would consider swinging for them. But if others' experience with them are poor then I'd likely just default to offset bushings.

Scigheras

Don't get the P2M style arms, they're shit. The washers around the adjusting bolts are weak and when you try to torque them down they just bend and deform. No experience on the others so can't comment there.

B serious

There's a lot of words in the OP, so I hope I'm following. I have questions

You do not currently have adjustable UCA's but are running -3.5 deg of camber.

How did you achieve that?

Why are you so worried about adjusters slipping? What is your intended use?

Why not just buy SPC ball joints?

Shift9303

1. I have Hardrace offset lower camber joints. They worked fine with my more conservative 17x9.5+51 setup however these 17x10+48s are too extreme. At my ride height I max out right around -3.5* camber. My eccentric bolts are at their most outward position last time I did a DIY alignment. In the picture I provided I had the sway bar disconnected and the car lowered onto a ramp to compress the wheel. That's not my static height.

2. Yes I'm worried about the ball joint plate sliding. These more generic arm just don't look like they have any way of securing your setting. For example the Ikeya arms have teeth in the sliding plate and arm to prevent settings from moving. I believe the Origin Fab product uses fixed spacers to adjust the camber. This is my Auto X and track car. I didn't actually rub when I took a quick spin to Walmart but obviously I'm not getting as much compression as I would on the track. I have just a paper thickness of space at the lip and if I have any steering angle I likely would rub.

4. Based on what I've seen with the SPC ball joint it seems some what more difficult to achieve granularity in its adjustment. I'd likely just set it at max inward position and from what I've read it's about the same clearance as offset control arm bushings. So in that case if there isn't much adjustability I'd just go with the later as a simplified solution. If these control arms don't hold position then I'd be in the same boat and just get offset bushings from Origin Fab or Baero.

B serious

It looks like you have offset lower joints..so thanks for confirming. You'll want to go back to stock lower ball joints so that you can clear the fenders with a reasonable amount of camber.

Why do you want granular adjustment?

No, you don't use full inward on SPC joints or adjustable UCA's. You set them in the ballpark of where you need them. I can describe to procedure if you are interested. Then your alignment person uses the stock eccentrics to finely adjust the alignment.

I highlighted set and adjust because they are two different things. If you are after a granular setting, then SPC joints or a sliding UCA meets your need. If you are after a granular adjustment, you want the Ikeya arms which have a tie rod style adjustment.

Offset bushings are an option, yes. The disadvantage is that you end up with plastic bushings in your suspension and the angle is pre-set with no adjustment.

Are you tracking this car or just street driving it?

Shift9303

This is my track and auto cross car. I don't street drive it much anymore besides to the track or the occasional weekend grocery run.

Having a wider range of adjustability and repeatability would be nice to fine tune setup and fitment as well as for future proofing purposes if my setup were to change. It's not an absolute must however if I can get more features for my dollar then I'd like to.

With the SPCs I'd likely need to set them at max inward position for the amount of clearance I'd need. At that point they become some what moot as adjusters and I'd just essentially have a fixed position solution. In that situation I'd rather use offset bushings which are simpler and don't introduce much more complexity. I haven't heard any complaints about them from local TT drivers. They also have the added benefit of being safer for classing if I ever decide to get competitive in time trials. No plans at this point but it's a check box for them vs other products. These budget sliding arms caught my eye since they looked like they might provide more adjustment range than SPCs however the adjustment area doesn't look very robust and Scigheras highlights one of my concerns. AFAIK the Ikeya arms don't use a tie rod. Some of their other products do but their S2000 arms uses a sliding plate that has teeth milled into the mating surfaces to prevent slippage and for repeatability which is another major difference between their products and these cheaper solutions. The Origin Fab upper control arms would probably be my #1 choice based on their design if not for price since I'm also budgeting for a roll bar and safety gear.

B serious

No, you don't need full inward setting to get enough camber.

You already have -3.5. Adding full inward would put you somewhere near -5 deg. If you then try to use your stock adjuster to dial that out by pulling the UCA in, there may also be interference created between the UCA and shock housing on compression. You're going to want to cycle the suspension to measure all that, plus all the bump steer you're going to be adding.

The above issue is created because you have offset front lower joints. My recommendation is to get rid of them if you want to prioritize sanity and wheel clearance.

OR...take the easy route. Your fenders are already flared. Just flare them TF out until they clear, without using any modification to the UCA.


Also...
SPC's and sliding arms make bad adjusters. You want to set them ONCE and then make any necessary adjustments through your factory adjuster. Once you torque the fastener(s), it tends to deform the washers. They are also difficult to adjust from an alignment tech perspective. Think of the actual mechanics involved in making them slide and then fastening them while the car is on an alignment rack. Fukken nightmare, bruv. Use them as a set and forget.

Your wheels aren't ground breakingly aggressive.

Here is a visual representation of what I am saying, if its more digestible.

I have 2 S2000's.

Black S2000 has 17x9.5 +47 and 255's with ONLY SPC upper joints, set to about halfway negative. The stock adjusters are the only actual adjustment, and I am easily clearing my fenders with room to spare, using -2.7 of camber. This car has rolled lips, but the stock fender shape. The fenders are pristine. No bacon, and I drive this car almost everyday and everywhere in summer.

My red S2000 has 17x9+40 with 255. I am using Megan offset lower joints. The stock adjuster is the only actual adjustment and I have them set so that the car has -3.7 deg of camber. I needed to fully mutilate the fenders for this to work.

The red car has a wheel fitment which is effectively 0.65mm more agressive. So for our purposes, we're going to agree that 17x9.5 +45 and 17x9 +40 are the exact same static fitment.

Now look at the difference in how the wheels sit, despite the red car having a full extra degree of camber and flared fenders.

B serious

Some quick trigonometry tells me that with your wheels, if you wanted them to fit like my black car, and you were using SPC uppers at about halfway negative, you would only need -3.25 deg camber. You can achieve the same with some form of sliding or infinitely adjustable UCA too.

Or...again, you can choose to buy nothing and just flare the fenders out. Idk why you wouldn't choose this path as a solution.

Bullwings

Where did you see the Origin Arms with the shims? The only one i've seen is the prototype that awhit has in his build thread - can't find them for sale anywhere.

Anyway, I actually just re-did my camber adjustment up front. I had the lower offset hardrace ball joint. I recently went back to OEM and installed the Baero version of the upper a-arm offset bushing. Two reasons - my upper A-arms were still on the original bushings, and I've been seeing a lot more broken front knuckles at the mounting points for the lower offset ball joint (seems that it adds an additional torque lever arm that adds a multiplier factor for the forces normally generated on that mounting point). I'm on 17x9.5 +47 wheels - massive amount of fender clearance available with this new config. I'm running -3.2 degrees up front as my preferred alignment.

Ikeya, Orgin, and Wisefab are the only aftermarket arms i would consider.

Shift9303

My fenders aren't actually flared, at least not any more than what a regular fender roll gets you. Any apparent flare would be from the camera lens. I'm not looking for more camber, only more clearance. Obviously I would set and forget the top arm and adjust through the bottom. I've done enough DIY alignments to know that fiddling with both upper and lower joints would be a nightmare. Any form of adjustability would be for additional operability if necessary in the future.

I would be looking for around 7 mm of additional space which what most offset bushings would get me. My 17x9.5+51 wheels are already extremely close based on photos of my car during cornering at auto X and track, TBH I'm surprised they even cleared with RT660s in the past. I was hoping that the 17x10+48 would fit similar, it's only 3mm I told my self, but deep down I knew it wouldn't fit since I've read GRM articles confirming that the stretch does also marginally widen tread width. The 17x10s stacked up on top of each other they're about 1 inch taller than the 17x9.5s with the same tire so somewhere along the sidewall contour they're 6 mm more outboard when mounted, or if you just go by math then 3mm at the hub and shoulder and 9mm at the lip. So with the additional width of the 17x10s as well as to bake in some additional clearance the 7-8mm that an offset bushing would get me is likely just right. It would be roughly 4-5 mm more inboard at the tread (compared to my 17x9.5+51s) which should be additional margin for any extreme situation like counter steer during a spin. The wheel lip would still stick out 1-2mm more however I won't reach that range of compression.

Would you be able to provide any measurements for the SPC's adjustment range? Your photos look like what I need however I'd like some more data points if possible. Based on photos I can find it looks like it has a bit less than a shank's width of sliding range from midline to the most inward position of the slot? The shank is about 10-15mm diameter right? Spit ball math tells me that's about the same or slightly more than what an offset bushing would get me. Also they seem like they would also change roll center? with the longer shank and seat. It probably would marginally raise roll center which isn't necessarily a bad thing but then I'd be going down the geo correction rabbit hole.


Origin Fab doesn't have the arms listed on their website but on instagram they have posted about taking back door orders. It's a beautiful part but not in my budget for the time being. Do you have any photos of your car for comparison? I'm aware that Bostonmaler uses them on his car (I think I noticed in one of his photos) and runs the same fitment wheel however he's on fatty slicks and there's a lot of other variables which makes it hard for me to eye ball on my car.


In all reality I was mainly curious if anyone had any experience about the durability of these budget arms. Main thing I observed was how thin the clamping plates on some of these were in comparison to even the SPC's sandwich plate as well as the size of their lock nut. It didn't really give me a good impression of durability or setting security so I figured I'd ask. Perhaps the absence of input is indicative that they are not a popular option and what ever else you can extrapolate from that. Leaving me between SPC and offset bushings I'm still leaning towards the latter for classing and simplicity reasons.