E36 5 Lug Conversion on an E30
Why do it?
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.
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.
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.
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.
Since my car is for the track, I got really stiff springs and won’t be running a sway bar.
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.
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.
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.
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.
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.
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.