The Rules

UPDATED 08-19-2021: Upload New Website.

UPDATED 09-05-2022: 2.2 Alignment Sugg/Specs.

UPDATED 11-14-2022: 2.1.6 Track Width

UPDATED 11-14-2022: 5.5 Windshield Material

UPDATED 11-28-2022: 3.13 Factory Rev Limiter

UPDATED 11-28-2022: 8.0 SCCA T2 Classifications

Mandated Spec Corvette Specifications v2.0
The main goal of Spec Corvette is to promote the equal competition of C5-generation Chevrolet Corvettes. Eligible cars are 1997 to 2004 C5 Corvette models: base coupe, FRC, and Z06. The rules emphasize driver skill and reliability, not driver budget. Any modifications not specifically approved are not allowed and will result in likely disqualification. Do not try to get away with unapproved modifications or we will disqualify you from the series indefinitely. If you are caught blatantly cheating, your car and the shop that built it will be announced as disqualified from the series.
Tech Bulletin 11-28-22: All SCCA T2 Prepped Corvettes grandfathered into Spec Corvette. Please see 8.1 below for SCCA T2 specific eligibility and rules.

1. Car Preparation Rules

1.1. Vehicle Eligibility
Any Corvette hatchback base model year 1997 to 2004, fixed-roof coupe (FRC) model year 1999 and 2000, or Z06 model year 2001 to 2004 that passes SCCA or NASA safety technical inspection can be used in Spec Corvette provided it is in compliance with the rules set forth below.
1.2. Competition Weight
Minimum competition weight is 3200 lbs. Competition weight includes driver, fluids, and all items, directly after you pull off the track post race.
1.3. Competition Horsepower
Maximum competition horsepower is 380 horsepower measured at the rear wheels. The GM LS6 engine is the benchmark engine. Each car will be required to submit the racing vehicles dyno sheet for approval before its first race and subject to random dyno testing. Racer dyno sheets will also be posted to the website for reference.
1.4. Competition Tires
Nankang NS-2R tires are the official tires of Spec Corvette. All cars must be equipped with the series specific Nankang NS-2R. Tires must be 315/30/18 on all four corners.
1.5 Reliability
Red Line Oils are the official lubricants of Spec Corvette. Fluids are open. Larger radiator, engine oil, transmission and differential coolers are allowed.

2. Chassis

2.1. Suspension
2.1.1. Penske Spec Corvette sealed units are the official coilover system of Spec Corvette. OEM and T1 mono-leaf springs and shocks are allowed. OEM C5 or OEM C6 uprights are allowed.
AFE Control Phase Out Plan: AFE Control Coilovers and Sway bars allowed until the end of 2020 race season. After the 2020 race season, AFE Control coilovers and sway bars will be out of compliance.
2.1.2. Spec Racing SCT-1 sway bars, polyurethane bushings, and end links are the official anti-roll system of Spec Corvette. These are a direct replacement for T1 sway bars. OEM C5, C5 Z06, and T1 sway bars are allowed.
2.1.3. A-arm bushings may be upgraded to monoball, delrin, or polyurethane. OEM rubber bushings in OEM A-arms are allowed.
2.1.4. OEM hubs are allowed, but not advised. OEM hubs are guaranteed to crack at the flange under frequent racing conditions. SKF racing hubs with ARP extended studs are allowed and recommended.
2.1.5. Bump steer kits are prohibited. Only OEM or factory replacement tie-rod ends are allowed.
2.1.6. Track Width - Maximum Track width allowable is 75.25" measured at the ground directly below the outermost part of the tire. This measurement is found using Trackspec 18 x 11 SPEC Wheel in +54 Offset. Spacers may be added to narrower wheels to achieve equivalent track width BUT MUST NOT EXCEED stated track width maximum.
2.2. Alignment (Revised 1/1/2022)

Front Camber is OPEN. Front Toe is OPEN. Caster is OPEN.

Rear Camber is OPEN. Rear Toe In is OPEN.

Rake and ride height settings are open.

Suggested Alignment Starting Points (Revised 09-05-2022)

Front Camber 2.7. Front Toe 0. Caster max.

Rear Camber 1.2. Rear Toe In 1/8.

3.5" front 4" rear to frame jacking points.

2.3. Brakes

Wilwood Disc Brakes AERO6Rs are the official big brake kit of Spec Corvette. This includes the radial 6-piston caliper and rotor kit (part no. 140-14557-N) and flexline kit (part no. 220-8176). OEM brakes are allowed. Race pad compounds are open.

All cars must run OEM or factory replacement rear brake calipers. Aftermarket 2-piece rotors are allowed for improved reliability and life but must maintain factory dimensions. Rear stainless brake lines are allowed. Race pad compounds are open.

2.4. Bracing and Bushings

Aftermarket engine, differential, and transmission mounts are allowed and recommended. Solid or polyurethane replacements are allowed. Transmission/differential bracing such as the DTE Differential Brace is expressly prohibited (see Section 4.5).

2.5. Wheels

Wheels must be 18" diameter and a minimum 10" width and maximum 11" width on all four corners. Wheels must weigh 20 lbs. minimum. Aftermarket wheel studs and lug nuts are allowed.

2.6. Interior

2.6.1. Vehicle must retain OEM dashboard. Dashboard may be cut to allow installation of roll cage. Removal of OEM radio and shifter trim is allowed.

2.6.2. Steering wheels are open. Quick-release steering hub is allowed.

2.6.3. Removal of airbags, carpet, insulation, AC/heating, windows, radio, passenger seat, parking brake, sunglass holder, mustache combs, gold chain lanyards is allowed.

2.6.4. Removal of non-essential wiring is allowed.

3. Engine

It’s real simple. Don't touch it. If you think it’s not allowed, it’s not allowed. If you think it might be allowed, it’s probably not. Be sure to ask questions if you are unsure about the specifications.

3.1. Engines must be stock LS6 or LS1. LS6 Engine is the benchmark engine. LS1 Engines upgradable with OEM unmodified LS6 243/799 heads, LS6 camshaft, and LS6 intake manifold. Cylinders may be honed during rebuild with maximum .010" over bore to clean up cylinder walls.

3.2. Exhaust manifolds must be stock. Pre-2001 cars may upgrade to LS6/2001+ exhaust manifolds. Removal of catalytic converters and exhaust after manifolds is open to modification. LS1 Engines with unported 241 heads, LS1 OEM camshaft, and unported LS1 intake manifold may add TPS Motorsport headers (part no. TPS-C5178LTH) and factory LS6 intake. Basically bone stock corvette LS1 can be equipped these headers and LS6 intake instead of upgrading to LS6 heads and cam as a budget friendly bump in horsepower. No combination other than stock LS1 as mentioned may use headers. (Updated 02-15-21)

3.3. All cars must be equipped with unmodified OEM LS1/LS6 throttle body and MAF sensor. Porting and any other modifications are strictly prohibited.

3.4. All cars must be equipped with the OEM Corvette airbox assembly. “Zip tie/flip tie mod” is allowed. Factory accordion bellows tube connecting to the throttle body must be run. Aftermarket smooth tubes are strictly prohibited. (Updated 08-19-21)

3.5. OEM LS6 intake manifold must be untouched. Porting and any other modifications are strictly prohibited. Stock LS1 engines can be upgraded to LS6 intake manifolds.

3.6. OEM LS6 243/799 heads must be untouched. Porting, polishing, and any other modifications are strictly prohibited.

3.7. OEM LS6/LS3 and factory replacement valve springs are permitted and recommended. PAC 1218 valve springs are also permitted. Valves must be factory sized and untouched.

3.8. Oil catch cans are allowed. Stock oil pump may be replaced with high pressure/high volume pump Melling part no. MEL10295 or MEL10296. Improved Racing Oil Pan Baffle Kit (part no. EGM-202) is allowed and recommended. OEM “Batwing” pan is allowed and recommended. Accusump oil injection system is allowed. Dry sump oiling systems of any kind are strictly prohibited. ONLY SCCA T2 grandfathered vehicles allowed to run dry sump during grace period.

3.9. Factory LS1/LS6/LS3 water pump with factory drive ratio is allowed. Under-driven water pumps are prohibited. Electric water pumps are prohibited. (Updated 05-25-21)

3.10. Katech Belt Tensioner (part no. KAT-A4425) is allowed to prevent belt walking.

3.11. OEM engine ECU is mandatory. Tuning for race gas and use of race gas is strictly prohibited. All cars must run local pump gas 91oct maximum. If your region has 94oct available, it must be written into region rulesets and approved by your region director.

3.12. Underdrive Balancer is strictly prohibited. Factory-sized steel balancer or ATI factory replacement steel damper permitted (part no. 917246). (Updated 08-19-21)

3.13. Factory Rev Limiter MUST BE MAINTAINED at 6600 RPM. Extended rev limiter to higher than 6600 is prohibited. (Updated 11-28-22)

4. Drivetrain

All cars must be equipped with the factory transmission, torque tube assembly, rear differential and housing.

4.1. All cars must be equipped with OEM MN6 or MN12 transmissions. All factory gear ratios must be maintained. Transmissions may be rebuilt with improved reliability (steel forks, bronze, etc.) but overall performance and gearing cannot be altered.

4.2. OEM LS6 clutch with factory steel flywheel is allowed. LS7 factory clutch with RAM Clutches 19lb aluminum flywheel is allowed to improve clutch reliability and bring overall unit weight back down to LS6 level.

4.3. OEM GM or Tilton Adjustable Clutch Master Cylinder is allowed. Please be advised to properly adjust the Tilton or you will have clutch failures. Extending clutch bleeder line is allowed.

4.4. OEM GM rubber guibos, aluminum solid, polyurethane guibos, or any combination of these are allowed for increased reliability. Factory prop shaft must be maintained.

4.5. All cars must be equipped with OEM rear differential and factory gears. Aftermarket differentials and LSDs are strictly prohibited. Rear gears maximum 3.42 ratio. All cars must use factory housing. Bracing is prohibited and is not needed.

4.6. Transmission shifters are open. We have had the best luck and recommend the factory C6 shifter. Cheap and reliable. Aftermarket shift knobs are open.

5. Bodywork

5.1. Trackspec Motorsports T1 Hood Louvers are the official hood vent kit of Spec Corvette (part no. C5T1HL). All hood louvers must be installed in the specified location. All other vents are prohibited.

5.2. Trackspec Motorsports/G-Stream 3” Rear Spoiler is the official spoiler of Spec Corvette. Spoiler must be installed in the specified location. All other spoilers and wings are prohibited.

5.3. The removal of the trunk tub is allowed to gain access for easy differential and transmission removals. The tub is allowed to be cut at the intersection of the vertical walls where it meets the horizontal trunk area. A closeout panel is allowed to be fabricated and installed to complete a flat surface across the trunk area. Fans and differential and transmission oil coolers may be mounted to this close out panel.

5.4. OEM headlights may be removed. Aftermarket covers or lights may be used in place of headlights as long as the top surface does not deviate from factory shape and plane. i.e Froggie style headlights not allowed.

5.5. Windshield - Factory style glass windshield must be used. Plexi or polycarbonate front or rear glass not permissible.

6. Safety

The safety rules within the SCCA General Competition Rules are the overriding guidelines with regards to safety specifications listed.

6.1. Roll cage must meet SCCA specifications for T1 (currently Section 9.4 of the 2021 SCCA GCR).

6.2. FFP Racing is the official fire system provider of Spec Corvette. All cars must be equipped with a 10lb. fire suppression system.

6.3. All cars must be equipped with a master kill switch.

6.4. All cars must be equipped with an FIA approved racing seat. Halo protection is strongly recommended. Sparco Racing supplies the official seats of Spec Corvette.

6.5. All cars must be equipped with an up-to-date FIA or SFI harness.

6.6. All cars must be equipped with a window net.

6.7. All cars must be equipped with front and rear tow hooks.

6.8. All drivers must be equipped with a Head and Neck Support (HANS) or equivalent.

7. Data

7.1. All cars must be equipped with hard-wired and operational front and rear video cameras.

8. SCCA T2 Vehicle Cross-classing Eligibility

8.1. T2 Cross-Classing is defined when any of the following is present: Penske DA Shocks, dry sump w/ battery relocation, battery relocation alone, Quaife Limited Slip Differential, T2 4 piston 13" front brake system, coil springs other than Eibach part number 0800.225.0550. Any one of these items will net a 3275 lbs min weight.

8.2. Factory LS6 engines with factory LS6 exhaust manifolds allowed to run. All T2 cars must produce under the 380 rear wheel horsepower dyno limit and have dyno certificate showing compliance.

8.3. 18x11 maximum wheel width permitted front and rear

8.4. 315/30/18 Nankang NS-2R tires must be run.

8.5. Penske Double Adjustable shocks permitted with T1 monoleaf springs

8.6. Add SPEC Rear Spoiler.

8.7. T2 cross-classing is permitted through the end of the 2024 season