Cento Challenge – Class 1B – Technical Regulations

Photo by Martin Gallagher


27.1. A Seicento or Cinquecento (sei /cin) Specification car is a fundamentally standard car 1108cc in compliance with the App 2 for speed events.

27.2 Cars must be in completely standard condition except for the specified modifications detailed in these regulations.

27.3 Every part or component of the car must be a standard production item identifiable as the manufacturer’s listed and numbered part or an equivalent generic or “spurious” part obtainable in the normal course from normal motor factors, except where alternative components are specifically permitted by these regulations.

27.4 Mechanical parts from a sei/cin may be interchanged

27.5 Cars must be in a road worthy condition (i.e. lights, horn, front wipers must all work) wheels, tires 165 / 65 / 13 e marked tires must be used, wheels may be replaced but must
be to the original size (5.5 j et +31 or 5.5 j et +27). Suspension is free, however dampers that use remote canisters are not allowed. Mountings to the body and hubs must be to the original points.

27.6. Bodywork: Cars must have bodywork that represents the manufacturer’s original profile, as in standard or manufacturer’s optional extra form.

27.7. All bodywork must be of the material provided as standard by the car manufacturer.

27.8. Front and rear bumpers must be retained and be of the same material and dimensions as those fitted by the manufacturer. The fitting of additional wheel arch extensions is prohibited.

27.9. Trimming / drilling of the body shell is not permitted.

27.10. Power steering may be removed

27.11. De-mountable strut brace’s may be fitted.

27.12. Detachable sump-guards, transmission, fuel tank and silencing system protection plates may be fitted.

27.13. Bonnet, door and rear door / hatch locks. as per MI Yearbook appendix 2

27.14. Sun-roofs as per MI Yearbook appendix 2

27.15. Interior: All trim must remain as originally supplied by the manufacturer And in compliance. MI Yearbook appendix 2. The exceptions are:
a) Full harness belts must be fitted as per MI Yearbook appendix 2
b) An alternative steering wheel of different diameter and style may be fitted.
c) The front passenger seat may be replaced with a competition seat.
d) Rear seats may have their backs folded down and securely fastened (or cut only where necessary to allow the fitting of a roll cage or seat belts)
e) Parcel shelves may be removed
f) Trim and carpets behind the rear seats in the boot space may be removed
g) Inside door panels may be re-shaped to allow fitting of roll cage as per. Appendix 2-16 or substituted by an alternative panel from a model variant
h) Safety air-bags must be removed or disabled
i) Additional instruments, switches and controls may be fitted providing the layout of the original components is not changed
j) Interior accessories may be added to improve comfort, convenience or safety, provided they do not affect the affect the performance of the car

27.16. The engine must in all respects conform to that originally fitted by the manufacturer for the model of car unless detailed below.

27.17. The flywheel may be lightened to a minimum of 5Kgs. (with starter ring fitted)

27.18 Either a standard camshaft or fiat 866 (regrind to 866 spec is allowed)

27.19 Cam timing may be adjusted, the original pulley must be retained but the drive dowel may be modified or removed. Use of a dowel is permitted to lock the drive.

27.20 Rods and pistons may be balanced to the lightest one in a set. (i.e. 1 unmodified)

27.21 The inlet manifold may be modified up to 30 mm of an inlet or outlet to enable matching of ports.

27.22 The cylinder head may be skimmed to min thickness 126mm

27.23 The cylinder head may be ported, valve guides may be modified.

27.24 Competition brake pads / shoes may be used (friction material free) fluid may be competition type

27.25 Fuel filter may be repositioned

27.26. Engine and gearbox mountings may be modified or replaced, provided there is no alteration to the engine or gearbox or their position within the car.

27.27. Additional engine braces are allowed, provided they utilise existing attachment points on the engine and a strengthening plate may be attached to the base of the sump-pan.

27.28. Fuel injection engines must retain the standard injection system complete with plenum chambers. The throttle body may be modified up to a max of 40mm

27.29. Air intake trunking to the air filter is free. Air filters and elements are free vapour canister and pipework may be removed.

27.30. All component parts of the gearbox and transmissions must remain as standard for the models sei/cin of car entered and be unmodified, except the clutch friction material which
is free.

27.31. The use of a limited-slip or torque-biasing differential is prohibited.

27.32. The original exhaust manifold must be retained as cast (standard) but the dimensions of the exhaust system after the exit from the manifold is free, it must follow the original routing and exit point and must carry a silencer. Catalytic converter may be removed

27.33. Additional straps and brackets may be fitted to the exhaust system.

27.34. The wiring loom and ignition and engine management system may be modified. The ecu may be modified by changing of the internal chip.

27.35. The battery may be changed and its mounting strengthened but its position must remain as standard.