A high level of vehicle performance is best achieved with a combination of low overall weight and select high quality components. Therefore, the modifications permitted for SpecE46 focus on these two areas.
The current release of the rules are here, and you can view previous versions in on our Google Drive rules folder.
A quick summary of the rules is below. Please note that these are for reference only and the full rules document is official.
SpecE46 is open to model year 2001 to 2005 USDM BMW 330i sedans and 2001 to 2006 330ci coupes. No ZHP, 330xi, wagons, or convertibles are permitted.
- Driveline
- Manual transmission, five or six speed (both have the same 2-5 gear ratios).
- Stiffer motor and transmission mounts using stock location permitted.
- Stock 2.93 open diff may be replaced with a 3.46 LSD.
- Shifter and linkage may be modified or replaced.
- Engine
- Stock M54 motor, flywheel and clutch may be upgraded.
- E36 exhaust manifolds and spec exhaust system supplied by BimmerWorld/Magnaflow.
- Cooling system improvements in known weak areas are permitted.
- A custom ECU tune is provided by Epic Motorsports in order to ensure compliance and maximize power/reliability.
- Suspension
- MCS single adjustable non-remote reservoir shocks with 750/850 springs.
- Front camber plates and rear shock mounts w/ spherical bearings.
- Polyurethane/Delrin control arm bushings.
- Sway bars must be steel, non-bladed, using stock mounting location.
- Rolling hardware
- Stock brake calipers and brackets. OEM style rotors are required. Pads, bushings, and flex lines are open.
- Wheels are 17″ with a maximum width of 9″ and must fit inside stock fenders. 16.2 pounds minimum wheel weight.
- Tires are Toyo RR (Dry) in size 255/40/17 and RA1 (Wet) in size 235/40/17.
- Body and interior
- Non-essential hardware and systems may generally be removed (HVAC, airbags, etc).
- Sunroof must be removed and covered.
- Chassis reinforcements in known weak areas are permitted.
- Interior, doors, and trunk may be gutted. Dash must be retained.
- No aerodynamic aids (wings, splitters, etc) are permitted.
- Minimum vehicle weight 2,850 lbs. with driver
Spec E46 is an officially recognized racing class with the following sanctioning bodies:
