Group ND Proposal
The Fuel delivery system type must remain as per the manufactures specifications in the Vehicle Specifications eg:
- Carburetted
- Mechanical Fuel Injection
- Electronic Fuel injection
Note: For both mechanical and electronic fuel injected cars there can be no more than 1 fuel injector per cylinder or rotor.
Only pure pump fuels may be used i.e. 98RON, 95RON or 91RON. Fuel blends such as E10, E85 etc are not permitted. "Race Only" fuels are also not permitted
Justification and Rationale
As other historic classes have permitted quite radical changes to carburetted vehicles. The same freedoms have been translated into both Mechanical Fuel Injection and Electronic Fuel Injection systems that are used on a lot of Group ND era cars.
Restricting the fuel to only pure pump fuels will curtail the development of very high compression, high revving and excessive forced induction engines. Thus keeping ND cars on a par with other category 5 groups and align with the group C rules of the day.
Related Discussions:
More Detailed information
Throttle Plates
On a carburetted car the original carburettor may be swapped for a different carburettor or replaced with multiple carburettors. The inlet manifold is free.
On fuel injected cars the number of throttle bodies is free as is the inlet manifold.
The total number of throttle plates can be no more than the number of engine cylinders or rotors.
Fuel Regulation
Fuel pumps and fuel pressure regulation is all free.
On Carburetted cars, elements that control the fuel regulation such as jets, vacuum units, springs and electro-mechanical mechanisms are all free.
On Mechanical Fuel injected cars, elements that control the fuel regulation such as metering units, distributing units, vacuum units, springs, air flow devices and other mechanical mechanisms are all free. The size of the fuel Injectors is free.
On Electronic Fuel injection cars, elements that control the fuel regulation such as the ECU, sensors and pickups used to provide the ECU with engine data are all free. The number of sensors and pickups used is also free. The size of the fuel Injectors is free.
Defintions
Mechanical fuel injection system: For the purpose of these requirements, a mechanical fuel injection system will be defined as any system where the injectors are operated solely by mechanical means, eg a pressure pulse. The inclusion of any electronic devices elsewhere in the system, is considered irrelevant.
Electronic fuel injection system: For the purpose of these requirements, an electronic fuel injection system will be defined as any system where the injectors are operated solely by electrical means, eg a voltage pulse. The inclusion of any mechanical devices elsewhere in the system, is considered irrelevant.
