320i

This is the car the 325i People make fun of, but 320's are as smooth as silk and don't go sideways at every corner. You can make them more fun with a little bit of work

To improve a 320i engine you need more airflow and better fueling.

1) Complete a full service and clean out air flow meter. In fact clean all the inlet system and seal any leaks

2) Flush through the injectors (redeX or similar) and check the earth on the suspension turret and the connector under the inlet manifold

3) Fit a mild chip from Speedtouch or Ant (look in traders) I would recommend Speedtouch at £30.00. but Ant does a fine product and gives great service.

4) Fit a 325i throttle body with 320i modified inlet manifold to keep a reasonable low torque. Don't fit a 325i manifold unless you want all top end power and no pull low down. (see wiki for details)

5) I would fit an adjustable pressure regulator, but I know the 325i owners don't like them. They do however improve a 320i with the above mods. Site it back by the throttle cable bracket, Inlet side of the engine, and make sure all the hoses and clips are in good condition

6) If you must fit a cone filter - build a heat shield. However the best solution is a standard filter box with a good free flow panel filter (Pipercross) then drill your front grill in line with the air pick up pipe. 10mm holes are fine just where the bottom of the grill fins are blanked off (you will understand when you look at the grill)

To improve the handling

1) Fit all new BMW rubber bushes front and rear. If you don’t do this, the rest is a waste of time.

2) Fit a good lowering kit such as Koni but only with a 30 or 40mm drop.

3) Fit an anti-roll bar to the back ( not all 320's had them )

4) New front control arms are nice if you can afford them or a Must if the joints are worn.

5) The ride will now be harsh, to smooth it out fit Sparco solid strut braces front and rear.

6) Wheels and tires of your choice, but make them at least 15”x 7”

To improve the brakes

1) Fit Goodrich braided hoses.

2) Fit new discs, (You don’t need drilled on a 320i.)

3) Fit Green Stuff front pads.

4) Fill with DOT5 fluid and bleed.

To improve the looks

1) You can’t, its perfect just the way it is

Do all this - It won't cost the earth and you will be amazed how good a 320i can be.

LEGAL DISCLAIMER: I am not responsible for any problems that may arise following this procedure. Any work you do is at your own risk.