After my friend Dave Adams' 92 330iC was rear-ended, he bought an E30 M3 and swapped his cabrio 5-lug parts onto the M3. I took that opportunity to buy the M3 5-lug parts to swap on my car because, well, I had nothing else to do that day.

Like the 328i conversion page, I decided to break down the parts by type (brakes, suspension, wheels). There are a few ways to go about this conversion, like you can use E36 front struts, E36 318ti or Z3/M Roadster rear trailing arms, etc. but I wanted to use the stock E30 M3 parts because everything bolts right up with no modification or headaches. The parts I used are the M3 front strut assemblies, trailing arms, calipers, rotors, EBC brake pads, E32 750iL brake master cylinder, E36 Racing Dynamics 17" wheels, E34 5-series 15" spare wheel, and my existing Racing Dynamics swaybars/springs and Bilstein shocks.

If you add all the figures up from the "new" column the total comes out to something ridiculous, but nobody buys new trailing arms and strut assemblies. In fact, a lot of times people sell the entire E30 M3 5-lug conversion "kit" for $1,000 or so with everything included except the wheels. Your best bet is to check the junkyard, online classifieds, BMW forums, or eBay for various parts and accessories that you may need because you'll save a lot of money that way.

NOTES

(1): The factory upgrade to this is the E32 750iL master cylinder, part number 34-31-1-156-643, BMW list price $398/avg Internet price $175. It's slightly larger than the M3 master (25mm versus 23mm), but more importantly it has the same 10mm brake line fittings as the stock E30 and is a direct bolt-on. The M3 master has one 12mm fitting and requires a different line.

(2): I used EBC Greenstuff front pads, part number DP2414.

(3): I used EBC Greenstuff rear pads, part number DP2690.

(4): M3s have a 33mm anti rattle bolt for the parking brake shoes. The non-M's have a 28mm bolt and it isn't transferable.

(5): M3s use 51mm strut housings, which are the same size as late 86+ E30 struts. However, you can't swap over non-M struts onto the M suspension because the M3 strut connects to the control arm by 4 bolts, while non-M3 struts are held by one nut.

(6): The M3 front swaybar is 19mm, most non-M E30s had a 21mm front bar. For most people it wouldn't be much of an upgrade unless you really want to reduce understeer.

(7): M3s 1989+ had aluminum control arms, which are the part numbers listed. 1988 M3s used the same steel control arms that the non-M RWD E30s used.

(8): Technically, all you need for the rear 5-lug are the rear hubs, but if you don't have a press it may actually be easier just to change the whole damn trailing arm.

(9): There isn't anything special about M3 rear shocks, so you can actually reuse your old ones. I did.

(10): Most stock E34 wheels have a +20mm to +22mm offset so they don't require spacers. Factory E36 wheels with a +41mm offset would require at least a 10mm spacer to clear properly; factory E36 wheels with a +46 offset would need at least a 15-20mm spacer to fit properly. E32 and E38 wheel offsets range from +13mm to +25mm so some may not fit properly because they'll stick out too much. E39 wheels have a different centerbore altogether and will not fit at all. (Remember, the lower the offset the farther out the wheel sticks out from the chassis, the higher the number the further in the wheel is.)