#26237 Request clarification on 9.1.3 D1.A.2

MAF, or AFM, etc., if so equipped. Air intake source shall be within the confines of the engine
compartment or stock location.
3. b. The original, standard intake manifold shall be maintained. No porting or polishing of the
manifold is permitted except as allowed by rule D.1.I these rules.
c. Carbureted engines
a. 1. Any carburetor jets, needles, and/or metering rods may be used in the stock or
approved optional carburetor(s). Alternate needle valves are permitted. Removable
jets may be replaced or resized. The number of carburetors may not be changed
from standard. No venturi (including secondary or auxiliary) of any carburetor may be
modified in any way.
1. 2. Certain cars have optional carburetors listed. On these cars, adaptor(s) may be
used to mount the optional carburetor(s), provided the adaptor serves no performance
function, i.e., plenum chamber, etc.
2. 3. External throttle linkage to the standard or optional carburetor(s) may be modified
or changed. Choke mechanisms, plates, rods, and actuating cables, wires, or hoses
may be removed. Method of operating the secondary throttle may not be modified.
(previously D.1.a.2)
5. 4. All single carbureted cars may fit an approved optional carburetor. Approved
optional carburetors are:
1 Weber 32 DGV/DGAV/DGEV
1 Weber 32/36 DGV/DGAV/DGEV
1 Weber 32/36 DFV/DFAV/DFEV
1 Weber 34 DAT/DATR/DATRA/DMTR
1 Holley-Weber 5200
Weber carburetor(s) with swaged fuel inlet fitting shall be replaced by drilling and
tapping the carburetor body for a threaded fitting. Fuel injection manifold(s) shall not
be replaced with carburetor manifold(s) from a different model, type, or engine size
in order to fit an optional carburetor. All cars equipped with multiple carburetors shall
run the original induction system, except for modifications allowed by the Authorized
Modifications Sections D.1.a., and D.1.a.2., above in these rules.
d. Fuel injected engines
6. 1. The engine management computer may be altered or replaced. A throttle position
sensor and its wiring may be added or replaced. A MAP or MAF sensor and its wiring
may be added. Other existing sensors, excluding the stock air metering device, may be
substituted for equivalent units.
2. External throttle linkage to the standard or optional carburetor(s) may be modified or
changed. Choke mechanisms, plates, rods, and actuating cables, wires, or hoses may
be removed. Method of operating the secondary throttle may not be modified.
2. External throttle linkage may be modified or changed. Electronic control of the
throttle is forbidden unless fit as stock. The method of operating any secondary throttle
may not be modified. Electronically actuated throttle bodies may not be replaced by
mechanical units unless specified on the vehicle’s spec line. Requests for alternate
throttle bodies will be considered on a case by case basis.
6. 3. The engine management computer may be altered or replaced. A throttle position
sensor and
its wiring may be added or replaced. A MAP or MAF sensor and its wiring may be
added. Other
existing sensors, excluding the stock air metering device, may be substituted for
equivalent
units.
7. 4. Wires and connectors in the engine wiring harness may be modified or replaced.