# K-MAC Camber plates, need first hand info...



## Lscman (Aug 5, 2003)

Are these strut mounts good or garbage?

I have an E39 5 series that sees 95% street & 5% Open/DE track duty. I want a way to dip the struts in & back for track days. I was intrigued by the urethane K-MAC's. Changing settings between track and street can be a little tricky, since it appears a wooden template of some type is needed to accurately index & document the strut rod positioning. I suppose two positioning templates could be made made for each side. 

I am not real keen on choosing an all-metal strut mount that adds harshness, although I'll go that route if necessary.

I suspect the K-MAC for 3 series is similar. I heard K-MAC's do not allow the strut rod to turn freely and I also heard they do not work with GC and some other coil-overs. These are some negative comments I've heard...I'm not sure how true or how serious. Do the stock strut mounts allow the rod to rotate when the steering is turned? Most domestic strut mounts do not allow rotation, but this causes uneven rod wear.

Thanks for any comments.


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## Raffi (May 18, 2002)

I have K-Mac plates with my Bilstein PSS9s on my E46, and the car turns on a dime. I do not change the camber between track and street settings, I just have it set at -2.5 degrees and it works really well for both applications.


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## TeamM3 (Dec 24, 2002)

changing camber changes the toe settings

adding negative camber from the street setting will cause toe settings to move outward (unless the steering rack is behind the wheel centerline like on a Mini Cooper, then it will move inward)

might prove beneficial for autox but may be a detriment on the track depending on where the street toe setting is and how much it changes as a result of the camber change.


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## Raffi (May 18, 2002)

But you can also get the toe set properly when you get the car aligned after installing the K-Mac plates.


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## TeamM3 (Dec 24, 2002)

Raffi said:


> But you can also get the toe set properly when you get the car aligned after installing the K-Mac plates.


not sure who misunderstands who here:

if you set it and forget it like you have done, yes.

If you want to change between a street camber setting and a race camber setting as the original post suggests, the toe will change with those camber settings as described above. Ideally you'd want to re-adjust toe as well, but taking it to the alignment shop everytime would be a major headache and expense.

He might be able to have it initially set at the race camber/toe settings (zero toe) on the alignment rack, then adjust camber-only to a street setting and see if the resulting toe-in reading is something he can live with on the street. If so, it could then be swapped back & forth between street & track camber settings without having to worry about toe.


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## Pinecone (Apr 3, 2002)

A couple of people have toe setting for M3s with GC setups that go from slight toe in with the street camber setting, and very slight toe out with the track camber setting.

Best is a single setting. But reseting for the track may work. The question would be will the templates give you eh accuracy you need to reset the camber back and forth.

And since this is tracking, not racing, a single setting will work fine.


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## Lscman (Aug 5, 2003)

I appreciate all the feedback on K-MAC design and function. Sounds like they do not fall apart or malfunction.

The use of templates to document & change settings will surely give you adequate camber and caster accuracy. The stock camber mounts are sloppy rubber and move around. Plus, the strut mount bolt holes have some clearance and the stock setup does not even allow adjustment. A 1/4" movement at the top of the strut does not even change caster or camber 0.1 degrees, so a tight-fitting template should have more than adequate setting repeatability. 

As for toe....sounds good to me! Obviously the tie rod connection to the spindle is above the ball joint. Probably not much. I prefer more toe out for track and toe in for street anyway. I don't have a problem dialing in a 1/4 turn on each tie rod to put the toe if needed. I've had alignment shops put paint marks on my steering linkage on various cars and it works just fine.

I'm not sure a single setting is "best". Optimum track settings require a little toe out and tons of negative camber that will quickly chew the inside edge of the tire to bits on the street. Maybe such a street setting is desired by some weekend warriors with low mile street kill cars, but not me. I don't want my inner tread disappearing while I'm cruising 70 MPH down the highway. I want my street tires to wear fairly evenly & provide a good tire patch for panic braking. Optimum streetable settings are a severe compromise for track use & will result in understeer and inside edge tread lift on the outside tire. At 0.9G's you want your camber setting to compensate for bodyroll and tire distortion caused by lateral forces. You want the tread to sit flat on the pavement. This requires you to dial in several degrees of negative static camber.


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## Raffi (May 18, 2002)

Lscman said:


> I'm not sure a single setting is "best". Optimum track settings require a little toe out and tons of negative camber that will quickly chew the inside edge of the tire to bits on the street. Maybe such a street setting is desired by some weekend warriors with low mile street kill cars, but not me. I don't want my inner tread disappearing while I'm cruising 70 MPH down the highway. I want my street tires to wear fairly evenly & provide a good tire patch for panic braking. Optimum streetable settings are a severe compromise for track use & will result in understeer and inside edge tread lift on the outside tire. At 0.9G's you want your camber setting to compensate for bodyroll and tire distortion caused by lateral forces. You want the tread to sit flat on the pavement. This requires you to dial in several degrees of negative static camber.


I think that -2.5 degrees of front camber is a great compromise for daily street use and track use once or twice a month, without much noticeable adverse effect on front tire wear, especially if you get your tires flipped on the wheel every few months. YMMV.


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## Lscman (Aug 5, 2003)

Raffi said:


> I think that -2.5 degrees of front camber is a great compromise for daily street use and track use once or twice a month, without much noticeable adverse effect on front tire wear, especially if you get your tires flipped on the wheel every few months. YMMV.


I don't believe in compromises. It takes no more than 15 minutes to change alignment. I don't think I'm going to flip my tires inside out on the wheels every couple months to distribute inner tread scalloping & cupping to both sides of the tread. Every visit to the tire shop subjects your wheels to more abuse from the tire changing machine and it costs about $30-$40 each time for R&R and rebalance. I'd rather change alignment settings and run the ideal setup for both track & street. Running the optimal alignment settings means street and track tires last longer (less cost), less hassle/work, less tire shop fees, less rim damage, better track handling, better street steering feel & less tread noise (from odd tire wear). JMHO


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