the instructions that came with the kmac kit kinda suck... but at the very top it says
"TAKE ALIGNMENT READING 1st. - fit time aprox. 3.5 hrs."
so first, 3.5hrs :eek:
and what do they mean by taking alignment reading first? i was just gonna put everything on then take it to an alignment place and get everything aligned, would that work.

They want you to know what the specs are before you start. Aligning the k-mac bushings is very tricky, and an alignment place is probably not going to do it for you, and almost certainly not going to do it correctly. It'll probably take you much more than the specified 3.5 hours.

well wouldn't i be able to tell if they did it correctly or not by looking at the alignment printout once they're done?

Here is another set of instructions for the Kmac rear bushings:

http://e30m3performance.com/tech_articles/susp-tech/ecc_bush/ecc_bush.htm

i understood none of that :(

In a nutshell, you can dial in maximums of 1.8 degrees of toe adjustment and 1.75 degrees of camber.

That means that if right now you are lowered and running 1.75 degrees too much camber you can dial that out. Now the downside is that you will also be dialing in a negative .8 dgrees of toe. So if your car is dead on in toe setting but only the camber is wrong, you will now have corrected your camber but hosed you ideal toe-in settings. In other words, it's a balancing game. Decide how far off you are willing to let your toe end up and then correct your camber up until that threshold.

Jose

the instructions that came with the kmac kit kinda suck... but at the very top it says
"TAKE ALIGNMENT READING 1st. - fit time aprox. 3.5 hrs."
so first, 3.5hrs :eek:
and what do they mean by taking alignment reading first? i was just gonna put everything on then take it to an alignment place and get everything aligned, would that work.

Let me try to shed some light on this. As an Alignment Technician for a company that deals with heavy collision and a lot of accident reconstruction I have probably installed a dozen of K-Mac kits into E12, E24, E28 and E30 chassis.
The rear kit is supposed to be installed by somebody with basic knowledge of suspension geometry because the final adjustment is a lot more involved then it seems. Once the bushings are installed they are actually a pain to rotate more then a few degrees at a time. By taking an alignment reading before installation of the bushings, the installer can actually get and idea on how to orient the bushings before the bolts are inserted and snugged up.
If I index the bushings during installation I can usually fine tune the rear setup in 15 minutes, I have spend as much as 2 1/2 hrs cleaning up some body elses mess because I did not have any idea how the original geometry looked like.

Now for a few general comments regarding rear alignment...
The K-mac kit serves well for lowered rear suspension where the basic suspension geometry was still intact before lowering, it is really useless when used to cover up damage to the rear cross member or arms. The suspension geometry on vehicles with stock suspension can usually be corrected without adjustable or off-set bushings by simply massaging the rear sub frame back to its original shape.
The rear tire wear is also not really influenced too much by negative camber, it's the combination of toe-out and negative camber that will produce tire wear. We have several suspension set-ups that run -4º camber on the rear with slight toe-in without any noticeable, excessive tire wear.
The main problem of the K-mac bushing and BMW off-set bushing set-up is that the adjustments of toe and camber a re interlinked due to the rotation of the bushings. A better way would be to modify the rear sub frame for a cam design, as Dinan offered in the 80's. Here is a link showing a similar set-up for an E30 chassis: http://www.strictlyea.com/features/e30subframe.html
The cam set-up makes adjustment of toe and camber much less interdependent, the adjustment range increases quiet significant.

Another comment on the choice of an alignment shop...
BMW provides alignment specifications for a loaded vehicle, basically 3/4 to full tank, nothing in the trunk other then 46 lbs of weight in the center, 150 lbs in each front seat and 150 lbs in the center of the back seat.
If the vehicle is not loaded down accordingly you might as well align it with a string wrapped around the tires. Trust me, it can not be done without proper loading.
Tire shops and mass marketers with an alignment rack are usually a poor choice due to the lack of qualified personnel. Ask around and see where the high line body shops in your area have their vehicles aligned. Also BMW dealer are not always a good choice as most of them don't have any technicians on staff that were alive when our cars were new.

Hope this helps, let me know if you need any more details.

Klaus

Wow! This information should be stickied. Good read.

ok so i can still install the bushings myself it'll just be a pain for the alignment shop to do it right?
also i don't usually have any other passengers especially not in the back seat, should i still have it all loaded down or could i just do the driver seat and a full tank?

ok so i can still install the bushings myself it'll just be a pain for the alignment shop to do it right?
also i don't usually have any other passengers especially not in the back seat, should i still have it all loaded down or could i just do the driver seat and a full tank?

Sure, depending on you mechanical ability you can install the bushings yourself.

All I can tell you is how we would be handling this at our shop:
Our basic charge for a loaded BMW 4-way alignment is $125, I will charge extra time to set-up aftermarket adjusters at an hourly rate of $100 if the vehicle is occupying an alignment rack. If I install the K-Mac kit at our regular labor rate of 3 hrs @ $85, it will usually take 10-15 minutes maximum to fine tune the rear suspension, because I took a prior reading (to verify basic geometry) and pre-set the bushings when I installed them.
If the bushings are just randomly installed, without any regards to desired correction, it will take me up to 2 1/2 hrs to sort out the mess, as I don't know what I can expect as a final result, so I have to try different scenarios. Things start adding up money and time wise real quick, I had several cases were my fixed estimate for the whole job including installation was lower then the final bill with the customer installed bushings.

To answer your question about the load procedure...
This subject is simply non negotiable, the published alignment specifications for BMW assume a vehicle loaded to the specifications. This has nothing to do with your personal driving habits or weight distribution. The specifications just simply reference a specific condition of the vehicle.
And, no, it does not work aligning the vehicle empty or with just weight in the driver seat, the end result is drastically different.
Because I am lazy, I created custom data files for my BMW's, with no loading and full fuel tank. I use these files for a quick alignment check, just to verify that everything is in the ball park. I demonstrate these files on a regular basis a training classes I hold for other technicians, it is sure amazing how many incompetent people work in tire and alignment shops...

BTW, I still don't have any idea what you are trying to achieve by installing the K-Mac kit, maybe you can give us an idea why you think your car needs this adjustment.

Klaus

the car is lowered and i had some bad inner tire wear.

it all started with a busted oil pan, then i figured i might as well do the suspension while i was down there. so i'm doing a complete suspension overhaul and getting some new tires and decided to get the kmac kits so the new tires won't wear so quickly.

i'm planning on going to a place that does lifetime alignments so pretty much it'll be like $195 or however much they charge. i've had some places take over 6 hours to do an alignment once trying to get everything right and they've never charged me extra. i maybe have to bring my own weights to load it down though.

Great article Klaus, good stuff.

For those interested, Ireland Engineering sells a kit like the old Dinan kit Klaus mentioned (Requires welding):

https://store.nexternal.com/ireland/images/E30RearCamberToeKit.jpg

Hey Klaus, I have seen race setups on 02's where they slot the outer mounting point horizontally and the inner vertically. They cinch everything in with star washers This can be done with minimal dismantling and parts cost. It also lets you use stock bushings if you want to keep things soft. Would you consider that a good, budget priced option for 6 owners?

Jose

on the instructions it says to have the thick lip of the bushings towards the outside.
does that mean the outside of the car or the outside of the trailing arm?
i.e. should both thick lips on each arm be pointing the same way or opposite directions?

Hey Klaus, I have seen race setups on 02's where they slot the outer mounting point horizontally and the inner vertically. They cinch everything in with star washers This can be done with minimal dismantling and parts cost. It also lets you use stock bushings if you want to keep things soft. Would you consider that a good, budget priced option for 6 owners?

Jose

Jose, nothing wrong with the approach as long as you use a proper torque retaining mechanism like star washers or a flat and a split washer. While it is a low cost alternative, it is very hard to move the bushings minute amounts in the slot for fine tuning the alignment settings, the ramps and cam bolts on the Dinan and Ireland Engineering kits make adjustments much more precise and reproducible. The end result is the same...
I actually use this technique in the shop when just one parameter is off, like one rear wheel is too negative in camber.

... i've had some places take over 6 hours to do an alignment once trying to get everything right and they've never charged me extra...

BTW, if a shop takes 6 hours to do a base alignment set-up, it's an indication that the technician is simply incompetent and probably works at a tire shop...

Klaus

Thanks Klaus. I am really leaning toward the Ireland kit. I can do the welding and metal work and then take it to someone for adjustment.

Do you think the weld in tabs require the same type of pre-measurement as the K-Macs? I was thinking that because they are easily indexed, it would be possible to weld the adjusters over the tab indexed at 0 and then hog out the tab. This would give you a net zero change but add the adjustability. I would then take it to a shop with the right equipment and have them do an alignment.

Also, do you think making these mods to the sub-frame would hurt the status of the car? Granted, I have no compunction about putting miles on my //M and will alternate between it and the spare rice burner as the whim strikes me. Hey, I bought the car because I like driving it. I realize not treating like a garage queen might make any valuation concerns moot. Just kind of checking around for alternate opinions.

Jose

Thanks Klaus. I am really leaning toward the Ireland kit. I can do the welding and metal work and then take it to someone for adjustment.

Do you think the weld in tabs require the same type of pre-measurement as the K-Macs? I was thinking that because they are easily indexed, it would be possible to weld the adjusters over the tab indexed at 0 and then hog out the tab. This would give you a net zero change but add the adjustability. I would then take it to a shop with the right equipment and have them do an alignment.

Also, do you think making these mods to the sub-frame would hurt the status of the car? Granted, I have no compunction about putting miles on my //M and will alternate between it and the spare rice burner as the whim strikes me. Hey, I bought the car because I like driving it. I realize not treating like a garage queen might make any valuation concerns moot. Just kind of checking around for alternate opinions.

Jose

I would agree that the Ireland Engineering kit is the way to go. The adjustment range is at least 3 times the range of the K-Mac bushing kit and you also don't run into the problems of the bushings falling apart in a short amount of time as you are using factory bushings.

Normally the ramps of the Ireland kit are mounted zeroed over the existing subframe holes, you mark the slot and the cut the material away with a grinder. I usually don't even remove the subframe, if it measures symmetrical left to right. Alternatively you can off-set the ramps a little bit for more adjustment range on the track or to hide some bend or asymmetrical parts (which would be a wast of time and energy if you are installing the kit to mask damaged parts).

For alignment purposes you should set the cams at dead zero to provide reference data for the alignment shop. You should also be prepared to provide some in ital alignment data (taken before the installation of the kit) and be able describe what end result you are trying to achieve with the installation of the kit (for example reduced tire wear, less oversteer...).

You ask about the impact on vehicle value with the installation of the Ireland kit? I can just speculate from the enthusiast level...
In my opinion, a major short coming of the early BMW chassis was the lack of factory alignment provisions for the rear suspensions. The front suspensions were usually over-build and stable, even handling spring settlement and minor wear parts without too much impact on steering geometry. Making the rear subframe adjustable can improve handling and tire wear problems to a drastic extend, especially if it is done nicely with a kit like the Ireland kit. Does it add to the value of an M car? Probably depends on the potential buyer or user. If the car is just driven occasionally, puttering around at free way speeds, I don't see much change in value or perception, for an enthusiastically driven vehicle that sees track use or is driven aggressively, I see a major value addition due to improvement to the factory design.

Klaus

Thanks so much for the input Klaus. This thread hijack is over. I started a new one hoping to consolidate camber setup info.