Class
Modification
Street
(128i/135i = DS, 1M = BS)
Street Touring
(128i = STX, 135i = STU)
Street Prepared
(128i/135i = ASP)
Street Modified
(SM)
Suspension:
Springs
N Y Y Y
Shocks
Y
Max of 2 external damping adjustments, no electronic controls, +/- 1" length of OEM fully extended
Y Y Y
Anti-roll (sway) bars
Front or rear, but not both Y Y Y
Strut tower bars
N Y Y Y
Adjustable Camber Plates
N Y Y Y
Alignment pin removal mod
Y Y Y Y
Slot upper shock tower holes
Y* Y Y Y
Upgraded Bushings
For upgraded sway bar only Non-metal Non-metal Y
M3 Lower Control Arms
N Y
(or camber plates / slotting upper tower holes, not both)
Y
(or camber plates / slotting upper tower holes, not both)
Y
Coil-overs (KW, AST, TCK, etc.)
N Y Y Y
BMW Performance Suspension (full kit)
N Y Y Y
Dinan Stage 1 Suspension (kit)
N Y Y Y
Dinan Stage 2 Suspension (kit)
N Y Y Y
Dinan Stage 3 Suspension (kit)
N Y Y Y
 
Brakes:
DS/BS STX/STU ASP SM
Upgraded pads
Y Y Y Y
Upgraded fluid
Y Y Y Y
Upgraded discs (rotors)
N Any equal or larger, must be metal Any equal or larger, must be metal Metal
Upgraded calipers
N Piston count equal or more Piston count equal or more Y
Stainless-steel lines
N DOT approved Y Y
Brake ducts
N Y Y Y
Speed bleeders
Y Y Y Y
Disable ABS
N Y Y Y
BMW Performance Sport Brakes (kit)
N Y Y Y
Dinan/Brembo Front and Rear Brakes (kit)
N If these bolt to standard location without adapters (?) Y Y
 
Wheels/Tires:
DS/BS STX/STU ASP SM
Wheels
Stock size +/- 1" diameter,
+/- .25" offset
Y Y Y
Tires
140 wear rating min, 7/32" tread min 285mm max, 140 wear rating min Y Y
Spacers
Resulting offset = +/- .25" stock Y Y Y
Fender lip rolling
N Y Y Y
Wheel studs
Y Y Y Y
 
Engine:
DS/BS STX/STU ASP SM
Spark plugs/wires/coil
Y Y Y Y
Air cleaner element
Y Y Y Y
Oil filter
Y Y Y Y
Thermostat
Y Y Y Y
Oil cooler upgrade
N N Y Y
Silicone Hoses
N Y** Y** Y
Intercooler upgrade
N N Y Y
Water Injection
N N Y Y
ECU flash/replace (BMW PPK, Cobb, Dinan, Proceed, etc.)
N N*** Y Y
Tunes (JB4, SSTT, JB+, etc.)
N N Y Y
Air intake
N Y Y Y
Exhaust (rear-section - ex: BMW Performance)
Y Y Y Y
Exhaust (mid-pipe - ex: N54 to N55 mid-pipe conversion)
N
2011+ (N55) models only
Any emissions legal Y Y
Exhaust (manifold)
N Any emissions legal Y Y
Exhaust (downpipe - ex: cp-e)
N Any emissions legal Y Y
Catalytic Convertor replace/remove
N Replace only - Any cat(s) allowed, must attach within 6" of OEM Y Y
Turbo upgrade
N N N Y
Boost controller
N N Y Y
Turbo Timer
Y Y Y Y
Blow-off valve
N N N Y
Compressor bypass valve
N Y Y Y
 
Transmission:
DS/BS STX/STU ASP SM
Clutch
N N Y Y
Flywheel
N N Y Y
Limited Slip Differential
N Y Y Y
Clutch Delay Valve Mod
N N N Y
 
Interior:
DS/BS STX/STU ASP SM
Seat replacement
N 25 lbs min, stock mounts, top higher than head center, fully upholstered Fully upholstered,
full back with headrest
Fully upholstered,
full back with headrest
Rear-seat removal
N N N Y
Short-throw shifter
N Y Y Y
Shift knob/boot
Y Y Y Y
Custom pedals
Y Y Y Y
Steering Wheel (BMW Performance, MOMO, Nardi, etc.)
N N Y Y
Safety Harness
Seats may not be cut for installation. Existing restraints cannot be removed. See stock Standard seat-belts may be removed to facilitate alternative restraints Y
Harness Bar
Two bolted attachment points, or 'C'-type with four bolted attachment points See stock See stock. 6-8 point roll-cages are also allowed. Y
Airbag
N N Can be disabled Can be removed
 
Exterior:
DS/BS STX/STU ASP SM
Body kit
? (13.2) ? (14.2F) ? (13.2) Y
BMW Performance Spoiler
? (13.2) Y Y Y
Replacement Kidney Grills
Y Y Y Y
Replacement mirrors
Y Y Y Y
Replacement side skirts
? (13.2) ? (14.2F) N Y
Replacement Rear diffuser
? (13.2) Y ? (13.2) Y
Replacement hood
N N N Y
Tow hook
Y Y Y Y
Trailer hitch
Y Y Y Y
Debadge
N Y Y Y
 
Other:
DS/BS STX/STU ASP SM
Disable DTC/DSC
Y Y Y Y
Remove radio/speakers/wiring
N N Must leave wiring, speaker holes must be covered Y
Weld sunroof
N N Y**** Y
AC removal
N N Y Y
Battery replacement
N Same voltage Same voltage Same voltage
Emissions removal
N N Y Y
Fuel cell
N N +/- 20%, same location 5+ gallons
Minimum weight
None None None 2400 lbs.
 


* 13.8E - Allowed provided it is an authorized modification by the manufacturer.
** 13.10J - Must be the same size/shape/location/stiffness/contour/internal wall texture as OEM
*** Flash/replacements are allowed provided they do not alter factory boost levels or traction control parameters. Even those which provide stock maps or "bypass" modes are not allowed; "Alternate software maps which violate these restrictions may not be present during competition, regardless of activation."
**** 15.2O - "Sunroof equipped cars may be converted to a solid-roof configuration provided a model without a sunroof is listed on the same line in Appendix A." - Does convertible count as a "model without a sunroof"?

Change Log:
12/7/2013 Updates for 2014 season based on approved proposal
6/8/2012 Swaybar updates for 2012 season
  Added wheel studs
  Added shift knob/boot
7/4/2012 Clarified exhausts (rear vs. mid section)
  Added Harness Bar
  Added Safety Harness