E36
5 Lug Conversion on an E30
Why do it?
Bigger brakes
More wheel choices with E36 offset
Cheap conversion for bigger brakes front and rear
Ground Control makes modified strut mount housings with E30 M3 sway bar brackets
A few things you should be aware of when doing an E36 5-lug conversion on an E30:
E36 M3 struts\spindles\hubs and brakes are not the same as E36 325 or E36 328s. They are not interchangeable. I don’t know the specifics, but if you want E36 M3 brakes, you have to get E36 M3 spindles\hubs. Get only E36 M3 suspension for the front
If you don’t want to do the conversion, Ireland Engineering (www.bmw2002.com) sells a couple of great brake conversions to be used with your existing E30 suspension.
I make many mentions of Ground Control (www.ground-control.com) suspension in this article. I do not work for them, but fully endorse their products based on experience and workmanship. The guys at Ground Control, in particular Jay and Dale, know BMWs, race BMWs and built these kits just for us car nuts. They helped me custom tailor my suspension to my needs and put together the kit from my existing parts and new parts.
REAR:
318TI
Rear
Trailing Arms
You need 318TI rear trailing arms.
I have read a few things online that the Z3 rear might work
considering
it is a modified E30 rear end, but I am not sure if the wheel offsets
will work
correctly. With the 318TI, I used
E36 17x8.5 M3 Motorsport wheels in the rear with 245/40 R17s. They fit with a simple fender roll and
no other modification to body work.
While you have the rear trailing arms out of the car, you should strengthen the sway bar bracket mounts with additional metal and welding. The MZ3 arms are further strengthened. See Xwebsite for more details.
Rear
Springs
You can re-use your existing springs because the rear hasn’t changed
much. I use Ground Control rear springs
with
adjustable perches. Jay at Ground Control recommended 800lb springs for
my
track use. At first, I thought
that was going to be to way too stiff.
But due to the geometry of the rear suspension and placement of
the
spring perches, it is the equivalent of a 400lb spring on other cars. I had 450 rear springs before and I
felt they bounced too much and I sometimes bottomed out.
With the new 800lb springs, I don’t
bottom out at all and the rear is really tight. I
will also not be running a rear sway bar with these stiff
springs and adjustable shocks.
Rear
Shocks
Ground Control is the exclusive distributor of Koni Externally
Adjustable rear
shocks for the E30 chassis. I used
to have Koni Internally adjustable shocks on my GTI many years ago and
having
to take the shocks off the car in order to change the shock dampening
is a real
pain. Pay the extra money and get
the externally adjustables.
Rear
Sway Bar
Since my car is for the
track, I got
really stiff springs and won’t be running a sway bar.
FRONT:
M3
Front
Struts\Spindles\Hubs\Brakes
The most important pieces
are the
front spindles and hub along with the brakes. You
can also use the M3 struts, but you may find yourself
buying new struts if you are going to race the car or take it on the
track. The E36 struts include the
housings not like the E30 which you use inserts and re-use your
housings. I used M3 struts with E30 top
strut
mounts to get everything bolted to the car and running.
I bought Ground Control shortened E36
M3 strut housing that took my E30 Koni adjustable front inserts. Ground Control also sells a smaller
diameter insert ‘cap’ that won’t rub the small Eibach springs I am
using. The original cap you screw into the
strut housing in just too wide and will rub on the springs under load.
E30
Top Strut
Mount with E36 Strut
You need to use the E30
top strut
mount to be able to bolt on the E36 strut to the car.
I started off using a simple rubber mount knowing that I am
going to be using the Ground Control camber plates and solid spherical
mounts.
’97
or ’98 M3
front control arms
These arms on the E36 go
into centered
control arm bushings. This is
critical because the geometry is
compensated in the control arm, not the bushing for these cars. This geometry plus the offset bushing
puts the wheel in the correct place for the e30 chassis.
Offset
front
control arm bushings
These bushings along with the control arms mentioned above will give
your e30
the correct centered placement of the wheel in the front wheel well. I used E36 17x7.5 M3 Motorsport rims in
the front with 225/45 R17s. They
fit great and you can see from the shot below how they are centered in
the
wheel well.
E36
Steering
Rack
I used an E36 non-M3 steering rack as well when I did my conversion. I had the engine out so it was a bit
easier to do at that point. My old
rack was leaking and the E36 gives me a closer steering ratio. The E36 M3 is ideal with an even
shorter XbyX ratio.
Steering
rack
Stops
I am installing the Turner Motorsport steering rack stops to help
prevent the
rubbing of the wheels on the inside of the front wheel well. When the wheel is turned to full-turn,
the big wheels rub the chassis.
The steering rack stops should help stop this.