Spec MX-5 Rules and Regulations
#35343 from Spec Miata Committee · Rule change · TB 24-01 (2024-01 Fastrack)
In GCR, Section 9.1.7.1. SPEC MX-5 (SMX), make edits as follows:
9.1.7.1. D. VEHICLE TECHNICAL SPECIFICATIONS
3. Chassis
b. All cars must use the front subframe PT# - NE51-34-800C
c. All cars must use the rear subframe PT# - NE51-28-800B.
Re-Letter Appropriately
4. Body
q. It is allowed to apply roll bar padding to the crash support bar (52-070) located behind the front bumper to mitigate
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damage to the bumper.
Re-Letter Appropriately
6. Engine Modifica�ons
6.2. Engine Block
Honing of cylinders is permitted to accommodate piston clearance so long as a maximum standard diameter is not
exceeded shown in Table 3.
b. The cylinders may be bored to accommodate piston clearance requirements so long as maximum permitted
overbore diameter is not exceeded shown in Table 3 below.
Table 3: Piston Sizes
Piston Part # Bore Diameter Max
Standard 0000-01-5310 87.6046mm (3.449”)
Allowed Overbore (.020) 0000-01-5310-OS 88.1126mm (3.469”)
6.13. Lubrica�on System
a. OEM engine oil filter is required; no subs�tu�ons permited.
b. OEM oil pump PT# L310-14-100J is required and no modifications are permitted.
c. Mazda Motorsports’ compe��on oil cooler adaptor kit with lines (part # 0000-01-5100KT) is required; no
modifica�on is permited.
d. An oil pressure sensor integrated into the required AIM data acquisition system is required. It must be operational, and a
proper value must be visible within the track data when viewed or downloaded in pre or post session inspections.
12. Suspension and Steering: Suspension
a. OEM control arms are required; no modification is permitted.
Re-Letter Appropriately
13. Hubs
c. OEM RX-8 rear uprights, bearings, hubs, and hybrid axel may be used in place of OEM MX-5 parts.
17. Electrical Equipment
d. One of the two OEM alternators (Mazda part # LF9H-18-300R-OA, or part # L3P9-18-300D) is required; no modification is
permitted.
g. One of the two OEM alternator drive pulley’s part # AJ51-18-W10 (60mm), or part# L813-18-W11(55mm) is required;
no modification is permitted.
Re-Letter Appropriately
20. Data Acquisi�on
1 A technical evaluation process for cars is available from the Series. Part of this process is the required download of AiM
Data files after each timed session (Qualifying 1 & 2, Races 1 & 2). Within 30 minutes of each timed session end, all
Series Competitors MUST send the AiM Data file (.XRK) for all timed laps of that session to the secure email address
(data@specmx-5.com), where data will be reviewed by AiM directly. Failure to adhere to this guideline from the Series,
or having non-functioning data, may be grounds for penalty or disqualification by the Series.
a. Vehicle must be equipped with current generation AiM data acquisi�on system (configurable in Race Studio 3) that
can provide on track data to AiM race studio 3. The data acquisi�on system may only read the OBDII/ECU data
stream. It is not permited to alter/manipulate data to and from the ECU. The AiM system may be u�lized to trigger
a switch I.E., cooling fans or diff cooler pumps but must be wired via a separate analog circuit.
Refer to Sec�on 17: Electrical Equipment above for installa�on requirements.
b. The connection at the OBDII port for the AiM system may be made in either one of two ways:
1. Through a dedicated OBDII AiM adaptor.
2. By direct wiring to the back of the OBDII port within 3” of the ODBII connector.
c. Fuel pressure datalogging is required.
d. Oil pressure datalogging is required.
21. Mandatory Video Camera
Cars running in Spec MX-5 must have a functioning video recorder/camera during all qualifying and race sessions as more particularly in
9.3.11. Upon request the SCCA a competitor shall provide their video recording/data which may be used by the SCCA for any purpose
including but not limited to rule enforcement and marketing. Failure to comply with a video request from officials, or having non-
functioning video, will be grounds for penalty or disqualification.