Control Arm and SCCA Class (ZSP to ZHP)

[driver145]

I want to upgrade my control arm from the standard/sport arm to the "performance arm". It is standard on the ZHP models. It is also available as a retrofit from the "BMW Performance Catalog".

Will this kick me out of STX?

[CodeMonkey]

Yes and No.
Is this a front or rear control arm?

It kicks you out if it's a front arm AND you use camber/caster plates, or anything other than the stock strut bushing.

You're fine if it's a rear arm, OR it's the front and you stick with stock strut bushing.

Rules are here: http://cms.scca.com/documents/Solo_R...Solo_Rules.pdf

[n2bimmer]

The front control arms on a ZHP have stiffer ball joints. Thats about it. Same size. Is that what your asking??

[driver145]

Originally Posted by CodeMonkey

Yes and No.
Is this a front or rear control arm?

It kicks you out if it's a front arm AND you use camber/caster plates, or anything other than the stock strut bushing.

You're fine if it's a rear arm, OR it's the front and you stick with stock strut bushing.

Rules are here: http://cms.scca.com/documents/Solo_R...Solo_Rules.pdf

Sorry. Yes its the front arm. I kind of wanted to add camber plates down the road... crap.

Originally Posted by n2bimmer

The front control arms on a ZHP have stiffer ball joints. Thats about it. Same size. Is that what your asking??

Correct. I am replacing them anyhow and its only going to cost me like $50 more to use the ZHP ones.

[cenotaph]

Originally Posted by CodeMonkey

It kicks you out if it's a front arm AND you use camber/caster plates, or anything other than the stock strut bushing.

You're fine if it's a rear arm, OR it's the front and you stick with stock strut bushing.

Has there been an official ruling on this? The way I would read 14.8.I.2 is that you're only allowed to adjust/add front camber at one point. Either camber plates, or adjustable/different front lower control arms. Therefore, I would think that you could replace the front control arms and use camber plates if the control arms don't change the camber by themselves. It may be worth it to get an official clarification.

Or you could just use camber plates with the ZHP control arms and see if you get protested.

[n2bimmer]

Originally Posted by driver145

Sorry. Yes its the front arm. I kind of wanted to add camber plates down the road... crap.



Correct. I am replacing them anyhow and its only going to cost me like $50 more to use the ZHP ones.

Or you can use Melye HD arms, They also have stiffer ball joints. Almost everyone is using this, including myself.

[ZHP]

ZHP control arms won't change the geometry, they simply utilize better ball joints. I would expect that would still leave camber plates as a viable option for increased camber.

[D. Hitchcock]

Hmm, the way I read it, you can use the ZHP control arms AND camber plates and run STX. As previously noted, see 14.8.I.2.

I'm assuming the ZHP control arms are nonadjustable and don't change the suspension geometry in and of themselves, but I don't know that for fact.

d.hitchcock

[driver145]

Originally Posted by cenotaph

It may be worth it to get an official clarification.

Or you could just use camber plates with the ZHP control arms and see if you get protested.

Is there someone I can ask that can make a "clarification"? Your last idea feels a little like cheating (even though I don't really get an unfair advantage).

Originally Posted by n2bimmer

Or you can use Melye HD arms, They also have stiffer ball joints. Almost everyone is using this, including myself.

hmm... You guys use them along with camber plates? If so, it should be the same situation.

Originally Posted by ZHP

ZHP control arms won't change the geometry, they simply utilize better ball joints. I would expect that would still leave camber plates as a viable option for increased camber.

That seems like what the rules are trying to allow for, but by the letter it seems like I am still breaking them. Not really sure how SCCA or the club I am racing with feels about that kind of thing...

Originally Posted by D. Hitchcock

Hmm, the way I read it, you can use the ZHP control arms AND camber plates and run STX. As previously noted, see 14.8.I.2.

I'm assuming the ZHP control arms are nonadjustable and don't change the suspension geometry in and of themselves, but I don't know that for fact.

d.hitchcock

Exactly, but I figured you couldn't modify it unless it said it was okay per the rules... and technically it isn't a stock replacement part... and it is a different control arm.

At least I can stay in this class for now and then I can find out about camber plates down the road...

[n2bimmer]

Yes, They are just regular fixed non adjustable arms, Only thing different is ball joints. Camber plates are also used.

[Mike S]

Just curious... which rule allows upgrading the ball joints in ST? 14.8.I.2 specifically allows replacing the control arm *or* using another method of camber adjustment. In my unofficial opinion, that allows replacing an arm (and its integral ball joint) but then excludes the use of a camber plate.

14.8.B allows replacing suspension bushings, but that doesn't encompass ball joints.

Totally unofficial comment: I don't see how one can replace the arm and ball joint then argue it didn't improve camber therefore the camber plate allowance still applies.

If someone really wants to do this, I suggest writing to the SEB for guidance. Send your inquiry to seb@scca.com and they'll get your answer for you. I suggest sending this asap. The Street Touring Advisory Committee has a conference call in a few weeks.

Mike

[CodeMonkey]

The thing is that they're non-stock arms for that car. If this was a SP car, then I'd agree that you could due to update/backdate. ST has no UD/BD rule so it's gotta stay stock.

14.8.I.2 On arm-and-strut (MacPherson/Chapman) suspensions, the lower arms may be modified/replaced OR other methods of camber adjustment as allowed by paragraphs 14.8.B, C, or G may be used, but not both.

it doesn't matter if the arm ACTUALLY adjusts camber/caster, the fact you're changing it is enough.

[driver145]

Yeah... unfortunately I was thinking the same thing as what you guys are saying.

I'll shoot that guy an email I suppose.

Thanks

[ULLLOSE]

Originally Posted by cenotaph

Has there been an official ruling on this? The way I would read 14.8.I.2 is that you're only allowed to adjust/add front camber at one point. Either camber plates, or adjustable/different front lower control arms. Therefore, I would think that you could replace the front control arms and use camber plates if the control arms don't change the camber by themselves. It may be worth it to get an official clarification.

Or you could just use camber plates with the ZHP control arms and see if you get protested.

There was a protest on this very matter years ago - Atwater Natl Tour or Pro, I want to say 05'. A WRX driver used an upgraded OE arm (non-adjustable, just a better part like in the case of the ZHP) from another year/model Subi, in conjunction with camber plates.

The driver received a DSQ for his interpretation of the rules.
http://forums.nasioc.com/forums/showthread.php?t=763230

And like Mike pointed out... Where is the allowance for ball joints in ST?

[driver145]

And it doesn't matter that these were available under the ZHP option, right? because then I would need the whole package or something? Of course, in my MY it was only available on the four doors anyhow... which would present another issue I suppose.

I suppose I will run STX this year with the ZHP arms. I am not in a hurry to get camber plates anyhow.

[Fair]

Big gray area, but one that seems to have some precedent. You can change the lower control arm in ST, but not do that + add camber adjustment elsewhere (camber plate). So in this case, running "non-stock" arms would be your one "camber correction" device on the front end. But what about the Lemforder & Mayle OEM replacements? What if one has a slightly better ball joint, that happens to be the same as the ZHP arm? Hmm, that's tricky. I'd do some research and see if the ZHP arms are a running update for all E46 models, according to BMW (factory approved, updated replacement parts does happen some times - and if there were ever a case for this to be needed, its the problematic E46 LCA ball joints). If so, then you could use them.

The aftermarket OEM replacements... that's trickier. Upgraded OEM replacement parts, done for reliability sake alone, is one are where SCCA rules are often found to be lacking.

Originally Posted by driver145

And it doesn't matter that these were available under the ZHP option, right? because then I would need the whole package or something? Of course, in my MY it was only available on the four doors anyhow... which would present another issue I suppose.

Yes, since Street Touring doesn't have the liberal "update / backdate" provisions of Street Prepared, to run a ZHP part on your car you'd have to do the same thing people in Stock class would - do the ENTIRE conversion to a ZHP model, down to even cosmetic things, and that model had to be available on your car's year model... which it didn't... sucks.

Originally Posted by driver145

I suppose I will run STX this year with the ZHP arms. I am not in a hurry to get camber plates anyhow.

Whoa whoa whoa.... don't confuse "heaviery duty ball joints" on the ZHP arms as having any performance benefit - they don't. Not running camber plates in autox is "tire suicide".... hard cornering will shred the outside of your front tires, and ensure understeer and slower times.

Camber plates = way more important! (and that's not just a sales pitch - its the truth)

[driver145]

Trust me... I want camber plates! I am just broke and have to replace the control arms right now. Furthermore, I don't want auto-x to determine the way I mod or repair my car. It is nice to fit in a class... but if I have to go to DSP, so be it. Its $50 for better control arms... I think I will use them. I don't plan on buying camber plates for a while anyhow... so I will run in STX probably this year and then next year if I am even still doing auto-x (would prefer track days) then I will just be in DSP (that class is slow anyhow in my region).

[Aarodynamics]

Considering that a ZHP isn't a different car from a ZSP but rather just a different suspension configuration from the factory, I can't imagine any way that you wouldn't be able to use them.

[Def]

If you're just doing local events, and likely not winning or even placing that well, I really wouldn't worry much about it and go with whatever arm you want to.

If you're not even autoxing it much, what's the harm in just running TimeOnly anyway since it'd just be for fun?

[Mike S]

Originally Posted by Aarodynamics

Considering that a ZHP isn't a different car from a ZSP but rather just a different suspension configuration from the factory, I can't imagine any way that you wouldn't be able to use them.

There are considerably more differences between a ZHP and the non-ZHP cars than just the suspension. In the SCCA, Stock class rules for option package conversion would apply here. The conversion would have to be 100% (other than the pieces already allowed to be changed under the STX rules.)

And since the OP already said the ZHP wasn't available as a coupe in his model year and the Street Touring category doesn't allow update/backdate as does Street Prepared, that conversion isn't an option.

Mike

[D. Hitchcock]

Originally Posted by Mike S

Just curious... which rule allows upgrading the ball joints in ST? 14.8.I.2 specifically allows replacing the control arm *or* using another method of camber adjustment. In my unofficial opinion, that allows replacing an arm (and its integral ball joint) but then excludes the use of a camber plate.

14.8.B allows replacing suspension bushings, but that doesn't encompass ball joints.

Totally unofficial comment: I don't see how one can replace the arm and ball joint then argue it didn't improve camber therefore the camber plate allowance still applies.

If someone really wants to do this, I suggest writing to the SEB for guidance. Send your inquiry to seb@scca.com and they'll get your answer for you. I suggest sending this asap. The Street Touring Advisory Committee has a conference call in a few weeks.

Mike

This all makes sense to me. I guess where I'm fuzzy is, if the ZHP control arm does NOT change suspension geometry why would it preclude the use of camber plates.

I'm in no way a competent rule interpreter, however.

I guess the ruling notion would be: The rules don't specifically allow for changing to hotrod control arms, so you can't.

But OE-style replacements with upgraded balljoints, due to updated replacement-part specs? Wouldn't that be OK?

dh

P.S. It's very helpful to have posts from such great autoX people as Mike, Mike and Terry. You guys all rock.

[Mike S]

Originally Posted by D. Hitchcock

This all makes sense to me. I guess where I'm fuzzy is, if the ZHP control arm does NOT change suspension geometry why would it preclude the use of camber plates.

...

I guess the ruling notion would be: The rules don't specifically allow for changing to hotrod control arms, so you can't.

You answered your own question. The only ST allowance for control arms is the one mentioned above. It does not allow you to replace a control arm *and* use camber plates. There's nothing gray about this - it's clear.

But OE-style replacements with upgraded balljoints, due to updated replacement-part specs? Wouldn't that be OK?

You have to find a rule that allows that. ST builds on Stock, so if there's a Stock or ST rule that allows upgraded ball joints, it applies. It should be legal if the factory issues a technical bulletin noting the change in replacement parts, or if you find some other factory documentation that the original part was superseded. But you can't replace with non-stock for your car parts just because they fit, and that applies to both OEM and OE parts.

To the best of my knowledge, there is no Stock or ST allowance to upgrade your ball joints. The lowest legal SCCA category for this would be SP where update/backdate allows the use of the part.

Mike

[driver145]

Thanks everyone. I ordered the ZHP arms and will run without camber plates in STX for a while. If I am competitive then I will not add camber plates until the points series is over. Honestly though, the times in my area for DSP are slower than STX. I might run both classes if they let me, but I doub't they will.

[jjvincent]

I run the ZHP arms. They are the same as the Meyle ones. It just comes down to that the stock arms have the ball joint mounted in rubber and the ZHP arms do not. They are different castings and look a bit different. In reality, the ZHP arms just hold the camber settings (lack of flex) and the stock ones do not.

[Mike S]

Originally Posted by jjvincent

I run the ZHP arms. They are the same as the Meyle ones. It just comes down to that the stock arms have the ball joint mounted in rubber and the ZHP arms do not.

Again... this is unofficial, merely my opinion, etc., etc., etc. What you describe does not sound ST-category legal. If you're not using them for competition it certainly isn't a problem, but if you're running at Nationals with that setup don't be surprised about a protest and DSQ ruling.

I'd really hate to see that happen because someone reads this thread and thinks it's all - the ZHP or the Meyle solution - legal.

Mike