Used BMW 3 series (e36) tuning

Tuning the E36 couldn't be easier, there are literally thousands of performance parts available from all the major performance part manufacturers ensuring it won't be difficult to find the part your looking for. Combine this with the fact that you can interchange the E36 parts with loads of other BMW models and the road to a road and track weapon couldn't be easier.

Used BMW 3 series (e36) tuning - Suspension

"The Ultimate Driving Machine" was not simply a slogan for the E36 BMW, the chassis is perfectly balanced and were, as now, the leaders in their class. 2 suspension options were available as standard from the factory, for the saloon you had the standard suspension or the M-Tec suspension and for the Coupe, the M-Tec suspension came as standard. The coupe was also available with the AVUS package which featured higher quality Bilstein units and eccentric front bushes for more negative camber.
When tuning the suspension, like any car, the first step is to build a solid foundation and this means sorting the bushes. Most E36s are getting on for 10-15 years old now and the standard bushings will be well past their best. The solution to this problem is to fit uprated polyurethane bushes from SuperFlex or Powerflex. Both companies have complete bush kits available off the shelf. If after fitting these bushing you can still hear knocking, the likely cause is worn top mounts, if your fitting coil overs without top mounts then the M3 top mounts are compatible and will give extra caster. At the rear E46 top mounts are a direct fit.
With regards to fitting uprated suspension, don't be tempted by fitting the M3 suspension, its not worth the hassle. For road and light track use H&R Springs combined with Bilstein B8 dampers. For regular track work Bilstein make an adjustable coil over kit as do KW.
To reduce chassis flex, the underbody cross brace found on the M3 and Cabrio can be fitted and this make a noticeable difference according to people who have tried it. These can be found at a breakers for as little as 10quid.
If your looking for quicker steering the Z3 steering rack has less turns lock to lock and is a direct fit.

Used BMW 3 series (e36) tuning - Engines

Concentrating on the larger 6 pots namely the 323, 325 and 328. The older 325 engines use a cast iron block, engine code M50. The 323 and 328 use an alloy block, engine code M52.
Engines:
325i - Capacity: 2.5litres - Power: 192bhp
323i - Capacity: 2.5litres - Power:170bhp
328i - Capacity: 2.8litres - Power: 193hp

Used BMW 3 series (e36) tuning - Engine Tuning

The reason why the 323 and 328 are down on power relative to the original 325 is that they were strangled by the inlet manifold from the 320. This was fitted for German insurance bands. This means that big gains can be made by fitting a flowed 325 inlet manifold with a bigger bore throttle body, this give approx 20hp and makes the car more responsive.
All the sixes respond to breathing modifications, a Dave F (E36Coupe.com) induction kit gives approx 10bhp. Supersprint is a popular choice for exhaust.
After this an ECU remap is a good idea, Pre 96 cars need to be chipped while post 96 cars can have their ECUs reprogrammed.
These breathing mods should give a
323 with 200bhp
325 with just over 200bhp
328 with 230bhp
US Spec M3 cams fit all these engine and give approx +10-12bhp.
After this your looking at an engine swap, although for the 325i, 328 crank, rods and pistons can be fitted.
BMW E36 Engine Swap / BMW E36 Engine Conversion
On the engine swap front the 3.0litre M3 motor is a much more straight forward process than the 3.2litre. The 3litre plugs into the existing wiring loom and connects directly to the 5 speed gearbox. M3 engines can be found for 1500quid although early M3s are creeping down to 5000 so it might be easier just to buy an M3 to start with.
V8 engines can also be fitted, the M62 being the choice motor and the E34 V8 5 speed gearbox will bolt straight in if you use the propshaft from a E36 M3 3litre. Alternatively if you use the later 6 speed box, the prop shaft from an E36 M3 EVO will fit. The biggest problems with a V8 swap is getting a sump mount kit to fit. Alpina do these parts off the shelf but they cost over a grand so the best option would be to modify the existing items if possible.
For the engine mounts an E34 mount can be worked to attach to the end of an E36 mount. This is cheaper than buying the Alpina mounts which are 360quid.
The steering column will also have to be changed to an item from a 325td to withstand the heat and obvioulsy a custom exhaust will have to be made up. If you get the orginal V8 loom and ECU, wiring shouldn't be too much of a headache and all the coolant pipes are available from Alpina. The V8 is also ripe for supercharging.

Used BMW 3 series (e36) tuning - Transmission

To quicken the shift a Z3 gear lever can be fitted, a direct swap, and when mated to a weighted E46 M3 gear knob a superb shift can be realised.
Diff ratios can be changed and an LSD can be fitted by using the rear diff off a 325, 328, 323 and M3. These all use a Type 188 medium diff. The smaller engine cars have a weaker Type 168 diff.
The M3 and 325s use a 3.15:1 ratio and the 323 and 328 use a taller 2.92:1 ratio.

Used BMW 3 series (e36) tuning - Brakes

Standard brakes are good so uprating to braided lines and DOT 5.1 fluid, grooved discs and uprated pads should be sufficient.
For big brake kits the BMW parts bin can be raided. To go from 286mm to 300mm use the discs and caliper carriers from a Z3 3 litre but use the existing calipers. (Carrier part number 34.10.6.758.120 - 106pounds from BMW)
Want bigger - Use BMW E46 330i calipers and carriers from the breakers and new discs and pads from a performance brake manufacturers such as Tarox, EBC, Ferodo etc etc. However this conversion makes for a long brake pedal, to cure this, fit an E36 M3 master cylinder and servo, though the parts for an E34 5 series are the same and much cheaper. You'll need 17inch wheels to fit the 330i discs.