Solid Control Arm Mounts - points

[scoobyej20]

Noob here to TT. I'm preparing an e36 M3 for TTD; not many points to play with (TTD* car). Where do I go for point questions - use this forum or email questions to regional TT director?

 

Questions such as: how many pointed are assessed for Solid Control Arm Mounts. The mount uses the same chassis mounting location as the OEM mount but it is a different design offering additional caster.

example part: http://store.bimmerworld.com/bwsport-trackcab-solid-control-arm-mounts-p1301.aspx

 

Closest rule, I think is E13, but this rule is for trailing arms, not control arms. E13 states: Changing the orientation or design of a BTM mounting point or pick-up point of a control arm for a panhard bar or trailing arms +1

 

Thanks.

[Fixxxercask]

Write an email to your local TT director.

 

I would say you got it right with the points. I am not 100% though. It may fall under E:9.

 

Replace or modify control arms (other than plates, shims, slots, or eccentric bolts/bushings

for simple camber/caster adjustment only) or RWD/AWD rear trailing arms (may have

spherical/metallic joint for the connection to the spindle/knuckle) +4

 

I think it is E:13 though.

 

Changing the orientation or design of a BTM mounting point or pick-up point of a

control arm for a panhard bar or trailing arms +1

[Rob S.]

I suspect since you are effectively changing the design of the control arm it would fall under 9) Replace or modify control arms +4. Also if the metallic bushing is on the subframe/chassis side then it would also fall under 24) Metallic and/or spherical-design replacement suspension bushings +3.

 

However always good to send Greg Greenbaum an email to check.

[D_Eclipse9916]

Noob here to TT. I'm preparing an e36 M3 for TTD; not many points to play with (TTD* car). Where do I go for point questions - use this forum or email questions to regional TT director?

 

Questions such as: how many pointed are assessed for Solid Control Arm Mounts. The mount uses the same chassis mounting location as the OEM mount but it is a different design offering additional caster.

example part: http://store.bimmerworld.com/bwsport-trackcab-solid-control-arm-mounts-p1301.aspx

 

Closest rule, I think is E13, but this rule is for trailing arms, not control arms. E13 states: Changing the orientation or design of a BTM mounting point or pick-up point of a control arm for a panhard bar or trailing arms +1

 

Thanks.

 

If its a 96-99 you dont want additional caster, and certainly not worth the points. An e36 M3 in TTD is definitely doable, and might be fairly quick. 225 A6s + springs would fit in TTD. Cant touch anything else though!

[dew-e]

I already have a question in to my local TT director and Greg about the Treehouse racing LCAB eyeball arms.

 

You are not modifying the control arm by using these, and the bracket for these mounts to the same exact location as the stock bracket.

 

What you have here is essentially a free-point LCAB bushing that uses a different bracket to mount the bushing. You are free to change wheel alignment by changing bushings, which is what this does. The specific BW part shown, and the Treehouse eyeball arms are delrin bushings, not full-metallic. Bimmerworld calls them solid, but not the same definition as the free points for non-metallic bushings.

 

Here are the rules in question.

 

E.9- Replace or modify control arms (other than plates, shims, slots, or eccentric bolts/bushings

for simple camber/caster adjustment only)

I.e. Suspension

1) Simple camber, caster, and toe adjustment by any method that does not alter suspension

mounting points

3) Non-metallic replacement suspension bushings

 

So the only change these provide is offset geometry of the bushing which is legal to the rules, and a non-metallic suspension bushing. All stock mounting points are maintained.

 

My concern comes about because of this rule-

E.13- Changing the orientation or design of an OEM mounting point or pick-up point of a

control arm for a panhard bar or trailing arms +1

 

So the real question is, is this seen as a change of the OEM mounting point or pick-up point. My take is no, the mounting point on the chassis of the car does not change, I was still asking for a clarification before i compete in my car to make sure I'm running legally. Since the rule doesn't say you can change the bracket to accommodate a non-metallic bushing, I have my fears that this is assessed at least 1 point.

 

But, even if this is ruled as a point mods, there are plenty of other free point bushings that fit into the stock bracket that do the same thing, without taking points.

[TurboShortBus]

Ah yes, the question of lollipops vs eyeballs. Greg and I have been discussing them, but I believe they were temporarily put on the back burner while the 2012 rules were finalized. I hope to resolve this issue soon.

 

Mark

[bsytracklife]

I believe people have been replacing control arm bushings with solid Delrin. (Its a super hard rubber/plastic) They drill offset holes in them to gain camber... I beleive there no points?

The Delrin is not cheap, so I just take the +2 and did adjustable upper ball joints.

[TurboShortBus]

Note that "what the guys on the forum say" may or may not correspond to what your regional or national directors think, and if it becomes an issue in tech/impound, then you know whose interpretation will prevail.

 

Mark

[Varkwso]

Note that "what the guys on the forum say" may or may not correspond to what your regional or national directors think, and if it becomes an issue in tech/impound, then you know whose interpretation will prevail.

 

Mark

 

 

I advised E9 on the control arms BTW

[Greg G.]

This is certainly a complicated modification.

 

First, it would be hit for +3 points for a metallic suspension bushing replacement. If one were to take the BTM bracket, and switch out rubber with polyurethane or other non-metallic material, then it would be a simple No-Points mod. But, this is not only changing the bracket, but also making a "solid" mount using "forged" metal that is essentially lubricated with a delrin liner. Similar metallic bushings use a greased metal sleeve instead of the delrin liner. Either way, while this is not a spherical joint, it is a replaced suspension bushing that does not fall under the No-Points modification, so takes the +3 points.

 

Then, the real tricky part comes. By changing the BTM bracket or "Control Arm Mount" as the part name states, one is changing either the mounting location of the control arm, or if one considers the control arm and it's bracket to be one unit, then changing the control arm itself. In fact, the company selling the part specifically mentions that this mount changes the suspension geometry (by changing the location that the control arm mounts). Now, if one states that the same mounting holes in the subframe/frame are used to mount these suspension parts, it could be countered that hypothetical brackets could be made for each control arm mounting location on the vehicle (inboard and outboard) that are 10" away from the usual mounting locations, using the BTM holes to mount these new brackets. I don't think anyone would then argue that there has been a relocation of suspension mounting points.

 

While these specific part is clearly not "worth" +9 points, there are theoretical parts using the same modification, but made in multiple locations and taken to more of an extreme in size/relocation, that could be "worth" +9 points. Therefore, I don't think that any of us would recommend this modification, and would recommend to find other ways to accomplish the goals (some stated above in this thread).

[dew-e]

The change in the bracket makes sense as Mark described it to me since you can't really verify that a more dramatic change in geometry hasn't been made. That was the main reason I checked into these. As these are sold, the geometry is identical to running an early M3 offset bushing, so yeah, definitely better ways to skind this cat. Didn't expect +9 though.

 

I guess the interesting part that I read differently is about the delrin just being a lubricating sleeve for a solid mount. How would you see this kind of bushing-

http://store.bimmerworld.com/ground-control-e30e36z3-delrinalloy-front-control-arm-bushings-p594.aspx. Doing a quick search, I see the corvette aftermarket calls them del-a-lum bushings.

 

The free TT bushing rule is basically just for a block of delrin/urethane similar in shape/size to the stock bushing, and not for replacement bushings that have some amount of metal in them. Or does that really depend on the design?

[Kubs]

The change in the bracket makes sense as Mark described it to me since you can't really verify that a more dramatic change in geometry hasn't been made. That was the main reason I checked into these. As these are sold, the geometry is identical to running an early M3 offset bushing, so yeah, definitely better ways to skind this cat. Didn't expect +9 though.

 

I guess the interesting part that I read differently is about the delrin just being a lubricating sleeve for a solid mount. How would you see this kind of bushing-

http://store.bimmerworld.com/ground-control-e30e36z3-delrinalloy-front-control-arm-bushings-p594.aspx. Doing a quick search, I see the corvette aftermarket calls them del-a-lum bushings.

 

The free TT bushing rule is basically just for a block of delrin/urethane similar in shape/size to the stock bushing, and not for replacement bushings that have some amount of metal in them. Or does that really depend on the design?

 

My understanding of the rule is any metal in the bushing (not counting the sleeve for the bolt) takes the +3 points. Poly or delrin cannot be INSIDE of metal. In the case of BMW bushings I would think anything thicker than the OEM bushing housing makes it a points mod, but if you could machine a delrin bushing to put in an OEM sleeve than zero points.

[dew-e]

Great way of explaining it, thanks. When I said metal in the other thread, I didn't mean to say that bushings with the sleeve for the bolt like you see in the middle of urethane. I know for BMW club racing these bushings were made as a way around the "solid" bushing rules. If it isn't solid metal, it fits their rules, so stick a little bit of delrin in there, and you no longer have a solid bushing, even though delrin is pretty darn solid. The no poly/delrin inside of metal makes the most sense and removes that loophole. If I was thinking about the rules that way, and not from a perspective of how other clubs interpret this kind of bushing I wouldn't have questioned it at all to begin with.