Pastelblau 520/6

[BertjeConti]

I have found a solution for my chamber problem, these are known items in the BMW 2002 scene and called " OFFSET ROLL-CENTER SPACERS", these plates have a double function:

1 give some extra negative chamber, about 1,7º
2 correct the "roll center" on lowered suspension

here is an example for the BMW2002, for E12 the dimensions are slightly different:



here a link with technical bla bla https://www.iemotorsport.com/bmw/2002-s ... amber.html

And a guy who made them for his 2002 Alpina http://www.bmw2002faq.com/topic/68936-o ... cers-done/

so now i'm searching for someone who will make them with my specs, and first check if there is enough clearance with the 14" wheels

[bmw e12 e21]

That's a nice option. Do you feel while driving you need those?

[loentje]

I've got them also on mine 02


greetings loentje

[BertjeConti]

These "OFFSET ROLL-CENTER SPACERS" just don't exist for early E24 or E12.

I don't have the tools to make them myself , and probably there aint enough room to place them and keep the 14" alloys. Another disadvantage is that these offset plates make the "SCRUBB-RADIUS" bigger, with the negative effect when taking corners, the inside of the car will raise more and the outside will drop more, because of the bigger SCRUBB RADIUS. And thats someting we do not want.

So I did some calculations what the effect of relocating the control arm mounts at the subframe would have. negative "Bump Steer" effects was my biggest concern.
These calculations weren't easy to do, because the suspension setup isn't as straight forward as most other cars, but after an evening calculating i had these results:

factory setup:
suspension travel 50mm in results in: add 0.7° neg chamber and 0.12°toe out
suspension travel 50mm out results in: subtr 1.1° neg chamber and 0.25°toe in

relocated control arms 15mm outwards setup:
suspension neutral: adds 1.3° neg chamber
suspension travel 50mm in results in: add 0.8° neg chamber and 0.14°toe out
suspension travel 50mm out results in: subtr 1.3° neg chamber and 0.35°toe in

Conclusion: BMW E12 factory suspension setup has very little "BUMP STEER" effect, and changing the control arm mounts a little outwards doesn't change it much.

So this is my approach to give the car some negative chamber and a little more track width.
The control arm mounts at the subframe will be moved 15mm outwards and 3mm upwards.

[bmw e12 e21]

Nice work!

[BertjeConti]

I've discovered why my control arms are 5mm short.

The control arms for the BMW E3 and E9 are almost the same as the E12 and early E24, with these diffences:
1) 5mm shorter
2) E3/E9 use 16mm bolts to the subframe, E12/E24 use 12mm bolts to the subframe.

So Moog probably took the old E3/E9 arm cast and only changed the rubber mountings to E12/E24 specs

Let this be a warning, DO NOT BUY MOOG ARMS for your E12 or E24

[BertjeConti]

Modiefied subframe

I'd already purchased a spare subframe for other plans.

Because we drive classic rally's with the E12 i had plans for a sump protector. In classic rally's you'll occasionaly go off road, mainly gravel roads or forrest roads. To mount a sump protector some mounting brackets are needed, and thats where the spare subframe comes in. Welding brackets at this subframe and build the sump protector around it on the workbench makes work much easier.

So after a good cleaning job i welded re-enforcement plates over the control arm mount holes and drilled new holes 15mm further outward and 3mm upward.

original mount hole:


first re-enforcement bracket welded:


drilled new mount hole:


other side:


arm test fitted:


next job is creating some brackets for the sump protector.

[Jeroen]

Some nice things going on again!

[BertjeConti]

sump guard

last weeks i've spent some time in the garage building a sump guard.

First thing i did was welding some brackets to the subframe. Because the sump guard will hide the oil drain plug it has to be made removable.
And because the sump guard will restrict the airflow around the sump i'll add a oil temperature sensor to keep track of the oil temp.

brackets with M10 threaded:






And building the sump guard on the subframe, the sump guard will reduce ground clearance with max 10~15 mm













Test fitting the sump guard:





and the lump painted





When once stranded in the dessert during a rally we'll have a nice barbeque grill for cooking a lion or other wild beast

haven't decided yet if the bumper stays of or not, when so i'll need some new indicator lights.



if there were some indicator lights out there that fit these holes would be perfect

[Jeroen]

As we say in Dutch... no half measures, thorough work!

[uwbuurman]

That's a serious skidplate!!

[bmw e12 e21]

+1

[BertjeConti]

Sump guard continued

Because i want some massive driving lights at the front to give the car a real rally look, the sump guard became brackets for these lights. To avoid a collision with the opened bonnet the driving lights should be mounted much lower as the top of the bumper, see this photo how much space is left with the bonnet opened:



Thats why my first idea was to get rid of the bumper and mount some universal indicator lights in the holes behind the original indicator lights, but while browsing photos of other rally cars this peugeot 504 gave me the idea to copy this setup to my BMW:



cutting the middle section out of the bumper would give enough room for 8" driving lights and indicator light problem solved too
But i wasn't happy to cut my fine shiny rust free bumper into 3 sections, so by browsing internet for a spare bumper, i found one perfect for me.
BMW organ spender Loentje had a E12 bumper with a big dent in the middle section, which is now mine.

[uwbuurman]

Cool! Can't you put on a e28 front Valance? Thry have the indicator lights in teh Valance, not in the bumper. It fits, I think. I can use yours if you want to sell it...

[BertjeConti]

Yeah Koos,
I saw your E12 front valence is a little bit demolished. But no i'll keep this front and use Loentjes bumper sectioned.

Nice try..

Oh but now i've a nice rust and dent free bumper in spare, which could hide your demolished valence.