AX Classification System FAQ

Why We Classify

Everyone participating in the GGC autocross program must classify your car. By going through this process, you will select a unique driver number and your car will be assigned a number of points which will determine the class you will compete in.

You may classify more than one vehicle, but only one vehicle may be active. Before your next competition event make certain that the car you’re driving is active on this page. The active vehicle will be highlighted in the list. To change to a different car, just click on it.

How to Classify

If you don’t already have an account at Boston-BMWCCA.org, create one here. Be certain to provide your e-mail address, and your first and last names.

Once you have an account, visit autox.s22536.p20.sites.pressdns.com to get started.

Select Driver Number

Each driver must have a unique driver number. Our system is the keeper of these numbers. Choose your number from the drop-down list and proceed to the next step.

Classify X-Class (Non-BMW or Mini)

If you are classifying a vehicle other than a BMW or Mini, you’re almost done. We just need to know the year, make, and model of your car. Type this information in the entry field just as the sample text indicates, then click the Submit button. You’re done!

Sharing A Car

If you’re sharing a car with another person, choose the “Copy someone else’s classification” button and pick their name from the list. That’s it! Their classification will be copied to your account and made active.

Classify a BMW or Mini – Select Year, Make and Model

If you are classifying a BMW or Mini, select the year of your car. Once selected the page will populate another drop-down list. Select the model designation for your vehicle.

Select Wheel/Tire Package

Depending on the model and trim level of your car, you may have optional factory installed wheels and tires. Choose the appropriate entry from the drop-down list.

Optional Equipment and Modifications

Your vehicle may have additional optional equipment and modifications. This page is where you will make those selections.

Tire selection

Select the type of tires you will run on your car for autocross events. Note that race compound tires (also known as r-comps) are defined as any tire having a tread wear rating less than 110. If you don’t know this value, visit TireRack.com and look it up.

The system will pre-select the type of tire it thinks your car came with from the factory. If the default value is not correct or you have installed different tires, click on the type of tire you have installed. Don’t know what you have?

  • All-season tires come standard on most non-M cars without the sports or performance package. They’ll clearly say ‘M+S’ on the sidewall
  • Summer tires come standard on most M cars and cars with the sports or performance package
  • Examples of cross-tread R comp tires: Michelin Pilot Sport Cup (not Pilot Sport or Pilot Sport PS2), Kumho Victoracer V700/Ecsta V700, Toyo RA-1
  • Examples of a grooved R comp tires: Kumho V710, Hoosier A6/R6, Hoosier AxS0x/SxSOx (A3S04, etc) line
  • Examples of non-DOT R comp tires: Hoosier R35/R45/R55/R60

Transmission selection

The system will choose a default value based on your previous selections. If the transmission in your car is different, select the type of transmission your car has.

  • Manual, SMG, or DCT: These are all manual transmissions. SMG and DCT have paddles in place of the third pedal for shifting gears. Your shift lever does not have “PRND…” indicators.
  • Steptronic or CVT: These are automatic transmissions with a sport or manual mode. Changing gears may be done with the gear lever or steering wheel mounted paddles, if equipped.
  • Fully automatic (no steptronic): A fully automatic transmission will have the traditional PRND shifter with no mode to manually change gears.

Shocks selection

Also known as dampers, shocks play an integral part in the handling of your car. Note that a stock BMW suspension means your car has BMW shocks and/or BMW springs. If you have a sport/performance pkg, M or JCW car, the system will select your default suspension type for you.

If you’ve installed non-standard parts, choose the item that describes your shocks.

  • BMW base shocks: original equipment, base-model shocks
  • BMW sport or performance package shocks: your car is equipped with the sport or performance package dampers
  • BMW M suspension shocks: you have an M car, or an M car with competition package, or you’ve installed an M suspesion on a non-M car.
  • Non-Adjustable or Single-Adjustable shocks: aftermarket dampers with or without adjustments.
  • Double-adjustable or Triple-adjustable shocks: your wallet will be significantly lighter if you installed one of these options as they are very expensive.

Springs selection

Springs play an integral part in the handling of your car. Note that a stock BMW suspension means your car has BMW shocks and/or BMW springs. If you have a sport/performance pkg, M or JCW car, the system will select your default suspension type for you.

If you’ve installed non-standard parts, choose the item that best describes your springs.

  • BMW base springs: original equipment, base-model springs
  • BMW sport or performance package shocks: your car is equipped with the sport or performance package springs
  • BMW M suspension springs: you have an M car, or an M car with competition package, or you’ve installed an M suspesion on a non-M car.
  • Springs without adjustable perches: you have aftermarket springs that are not height adjustable
  • Springs with adjustable perches: you have aftermarket springs that are height adjustable
  • Springs along with major suspension changes: you have installed aftermarket springs and have made additional geometry changes to your suspension that may include relocation of mounting points, custom control arms, or other extensive modifications.

Differential gearing modifications

If you’ve installed a different ratio rear differential, or modified your differential with a new ratio gear set, choose this item.

Drivetrain modifications

If you’ve installed a lightweight flywheel, choose this item.

Weight reduction modifications

Saving sprung weight can significantly increase the handling, braking, and acceleration capabilities of your car. We have done extensive testing and have calculated points for the most popular weight saving modifications.

sprung mass (or sprung weight) is the portion of the vehicle’s total mass that is supported above the suspension. The sprung weight typically includes the body, frame,  internal components, passengers, and cargo, but does not include the mass of the components suspended below the suspension components (including the wheels, wheel bearings, brake rotors, or calipers.

If you have removed any factory part listed here, and/or replaced a factory part, choose all that apply. NOTE: If you’ve removed your rear seat and/or trunk lining and have installed a roll bar, partial or full cage, do not select that item from the list.

  • Aftermarket sport seats: you’re replaced your stock seats with sport/racing seats
  • Rear seat removal and/or removal of trunk lining: see note above.
  • Stripping of interior: you’ve removed the dash, glove box, door panels, headliner, center console, etc.
  • Lightweight hood and/or body panels: you’ve replaced a factory panel with a lightweight version
  • AC removal: you’ve removed any part of your air conditioning system
  • Airbag removal (other than steering wheel airbag): you’ve removed door, a-pillar, or other airbags
  • Interior carpeting and/or sound deadening: you’ve removed the carpet, or ground away any amount of sound deadening material. This is effort intensive – you’ll know if you did it or not.

Additional weight reduction

This option should only be used if the items you remove are not included in the “Weight reduction modifications” list above. If the sprung weight was removed while installing an OEM part from the same make and model, you should not classify that weight here.

Examples of what NOT to classify:
  • Removed fog lights and replaced with delete panels
  • Installed lighter wheels and/or tires
Examples of what TO classify:
  • Removed metal from door shells, rear deck, or any other area of your car
  • Removed and did not replace exhaust system or suspension components
  • Removed glass and/or replaced with lexan or other lightweight materials

Add up the total weight savings for the removed items and select the appropriate range from the list of options.

Front camber modifications

Increasing negative camber is a significant handling improvement. Note that this option only applies to parts ADDED to the car that increase negative camber (camber plates, shimming the struts, swap strut hats, etc) and does not include the additional camber gained from alignments or lowering of the car.

  • If you’ve increased front negative camber on your e30 3-series and prior, or your e28 5-series or prior, select this option.
  • If you’ve increased front negative camber on any other vehicle, select this option.

Rear camber modifications

If you’ve increased rear camber on your e30 3-series and prior, or your e28 5-series or prior, select this option.

Sway bar modifications

If you’ve changed the front sway bar or you have the BMW active rollbar option, select the front sway bar item. The BMW active rollbars option is treated the same as having aftermarket sway bars.

If you’ve changed the rear sway bar and do not have adjustable rear spring perches, select the rear sway bar item. If you have adjustable spring perches, do not select this item.

Front wheel change in width

If you’ve installed wider front wheels than your car had from the factory, select the item that  matches the increased width measurement.

Rear wheel change in width

If you’ve installed wider rear wheels than your car had from the factory, select the item that  matches the increased width measurement.

Limited Slip Differential

The system will select this item automatically if we believe your car had one from the factory. If your car did not come from the factory with a limited slip rear differential (LSD) and you installed one, or we made a mistake, select this option.

Engine modifications

We provide two methods for calculating points for your engine modifications. You may choose your modifications from our list and accept our points values, OR you can enter the rear wheel horsepower of your vehicle as measured on a dynomometer.

Choose from our list:
  • Big bore throttle body: select if you’ve installed one
  • Underdrive crank pulley: select if you’ve installed one
  • Removed cats: select if you’ve removed your catalytic converters
  • Manifold: select if you’re replaced your intake manifold
  • Headers: select if you’ve installed aftermarket headers
  • Exhaust: select if you’ve replaced your muffler
  • Injectors: select if you’ve replaced your injectors
  • Air Intake: select if you’ve replaced your stock air intake
  • Underdrive pullies: select if you’ve installed assessory underdrive pullies
  • Distributor: select if your car does not have electronic ignition and you’ve replaced your distributor
  • Valves/Head work: select if you’ve modified your valves or had head work (like port/polish)
  • Software (OBD2 naturally aspirated): select if you’ve installed different engine management software on your non-turbo/non-super charged engine
  • Chip (OBD1 naturally aspirated): same as above for cars with OBD1
  • Carbs: select if you’ve modified or replaced your carbeurator(s)
  • Fuel injection in place of carbs: select if you’re installed fuel injection on a car that was carbeurated
  • Cams: select if you’ve replaced your original cams with a different grind
  • Supercharger pulley reduction: select if you have a supercharger and installed a smaller pulley
  • Piston/bore or stroke or compression increase: select if you’ve bored, stroked, or otherwise increased compression of your engine.
  • Chip/Software (turbo engine): select if you’ve installed different software or a piggy-back tuner on your turbo car.
  • Supercharger (not twinscrew): select if you’ve installed a non-twinscrew supercharger
  • Turbo or twin-screw supercharger: Select if you’ve installed a turbo or twin-screw supercharger on a car that did not include this feature from the factory
Rear Wheel Horspower Number:

If you’ve had your car dyno’d and know your rear wheel horsepower, select this option and enter the supporting data. Note that you will not have points deducted if your dyno results or horsepower claim is lower than the factory claimed rear wheel horsepower for your car.

No Engine Mods:

If you have not made any engine mods, click this button.

Run in Higher or Non-Compete Class

You may decide that you want to compete against drivers in a higher class. Select that class here: Note that if you choose to run in the Gonzo class, your base points will be increased to 80 which is the minimum number of points for that class. Gonzo times are indexed for all events. For regular season events, 80 points will be used if you run in this higher group. For Top Driver Shootout, your actual points will be used in this calculation.

You may also decide that you do not want to compete for a class trophy during the regular season. If this is your intention, select (N – Non Compete) from the dropdown list.

Save Classification

Click the “Save this classification to my user profile” button and you will be returned to your home page.