Well since noone was willing to share their front control arm angles with me in my previous post I have decided that I need to drop the mounting point of the front control arm to the spindle anyway :) I really think it needs to move down upwards of an inch. Whatever I guess, its a guess, but I have some theories and some nifty pieces of software one of my buddies gave me that are steering me in the right direction.

So for me it makes more sense to modify the stock spindles with some spacers that I'll make on a lathe to accept the taper of the control arm / tie rod ends and then machine the spindle down so I can spin the nuts on after I tig weld them on. I think I will be somewhat limited to the amount of gain but my logic is that I wish to continue to use the stock BMW control arm rather than use a fabricated one to accomplish my roll center fix.

Has this been done? Does it just sound stupid? Does someone already make a "drop spindle" for the E36? Questions, questions...

We are working on a production version of an E46 Arm that corrects the roll center for race cars if you are interested. We are just waiting to receive the prototype for final fit right now.

Rob, any idea about the cost? I was curious as to the construction too, are they made from tubes or is a modified E46 control arm?

I'm sorta probing the net right now looking for some E36 spindles in the meantime. I'm doing this all for an autocross car so maybe I should just work on my driving instead :) I live in the NE so we tend to get a little goofy in our long off season.

We are using E46 arms with some light machine work to accept a bearing cup. We found a way to buy them before the balljoint gets pressed into the hole in the arm. This makes the core material reasonably priced. We will have several options for arm setup with offset and centered cups etc. It will be more reliable and just as effective as tubes for our intents. We wanted something that was rugged and easy to maintain and setup. We used a similar system on the E46 World Challenge program. We could modify spindles for you too I guess. We do it both ways depending on what is needed.

No pricing yet. They won't be too bad.

Rob, isn't the E46 arm longer than the E36 control arm? Is there a product that will be available for the E36 too?

We are using E46 arms with some light machine work to accept a bearing cup. We found a way to buy them before the balljoint gets pressed into the hole in the arm. This makes the core material reasonably priced. We will have several options for arm setup with offset and centered cups etc. It will be more reliable and just as effective as tubes for our intents. We wanted something that was rugged and easy to maintain and setup. We used a similar system on the E46 World Challenge program. We could modify spindles for you too I guess. We do it both ways depending on what is needed.

No pricing yet. They won't be too bad.

Rob, isn't the E46 arm longer than the E36 control arm?

I can answer, having had various flavors of E30, E36, E46 and now custom tubular arms on our car. The E46 arms are longer than E30/E36 in both directions away from the inner balljoint. The E46 M3 control arms are longer still with regards to track width. You can gain even more width by using an offset outer spherical (which is what we ran in the past on normal E46 control arms). We now run tubular arms that are more like E46 M3 width under widened E36 fenders.

Remember if you start playing around with the control arm mount to the upright, you'll also need to play around with the tie-rod mount to the upright.

Also, if you plan to use E46 arms on your E36, you'll not only need to have fenders than can accept the extra track width, but you MUST use an offset bearing cup and you'll probably still need to shave down the outer portion of the control arm to keep it from rubbing on your brake rotors (depending on the offset and thickness of your particular rotor setup). Been there, done that, filed down the aluminum to prove it. :) You will also need to create a custom bearing cup to press into your lollipops since the E46 arms extend back further than the E36 arms.

Yikes Brian, that sounds like a lot of items to deal with. Maybe I should try just modifying a set of stock E36 M3 control arms to accept an aftermarket bearing cup and spin out a spacer on the lathe.

I'm just afraid I don't have the know-how to mount the bearing correctly into the control arm. I know I saw some pictures of E46 control arms with this done somwhere on the web :)

I can answer, having had various flavors of E30, E36, E46 and now custom tubular arms on our car. The E46 arms are longer than E30/E36 in both directions away from the inner balljoint. The E46 M3 control arms are longer still with regards to track width. You can gain even more width by using an offset outer spherical (which is what we ran in the past on normal E46 control arms). We now run tubular arms that are more like E46 M3 width under widened E36 fenders.

Remember if you start playing around with the control arm mount to the upright, you'll also need to play around with the tie-rod mount to the upright.

Also, if you plan to use E46 arms on your E36, you'll not only need to have fenders than can accept the extra track width, but you MUST use an offset bearing cup and you'll probably still need to shave down the outer portion of the control arm to keep it from rubbing on your brake rotors (depending on the offset and thickness of your particular rotor setup). Been there, done that, filed down the aluminum to prove it. :) You will also need to create a custom bearing cup to press into your lollipops since the E46 arms extend back further than the E36 arms.

Yikes Brian, that sounds like a lot of items to deal with. Maybe I should try just modifying a set of stock E36 M3 control arms to accept an aftermarket bearing cup and spin out a spacer on the lathe.

If you aren't comfortable doing the work yourseld and if Bimmerworld isn't going to be offering up the E36 arms as an off-the-shelf part, I'm sure RRT can fab some up for you along with some matching tie-rods. For that matter, they may have a set laying around the shop somewhere from our car since we decided to go the E46 route a few years ago instead of using the E36 parts. Call them up and talk to Barry.

www.rrtsuspension.com

Now for a potentially really silly question . . .

Is there anyone who offers a similar solution for the E36 like the one Gustave offers for E30s?

See pics here: http://gsperformance.com/products/rc-spacer/pic-2.jpg

I haven't read the rules lately, but I'm sure it would be safe to assume roll center spacers wouldn't be IP legal. But, they would be nice to haves for dedicated autox/track cars.

GrifM3
Dinan S2

RRT does, but its basically a custom per order item. Since the OP is in NJ though, its a quick drive down to RRT :)

For the OP, care to elaborate on your theories and software?

Did you collect your own data from your car?

This is not an easy task, nor is there an easy solution. There will be quite a bit of tuning involved, altering not only track width, but ride height, bearing offsets, bump steer, etc.

How low is your ride height?

We can assume this is a dedicated race car, right?

Sounds like you should just go tubular. You'll all the adjustment you'll need, and won't have to fuss with any OEM equipment. RRT has been there, done that. Tubular is the way to go if you want the total solution. You can definitely get pretty far with the e46 components modified on the E36 though, Watts car is a good example of that.

Depending on how much you raise the spindle and how much you change the width, you'll also want to look into raising the inner tie rod mount, like the Motorsport Tie Rod kit does.

I'll test fit some of the stuff you buy! This is the same thing that I have to do.