Vehicle: 20-20 Cadillac Class: GT Vehicle Manufacturer: Year and Model: General Motors 20-20 Cadillac This specifications form was developed by SCCA Pro Racing and will be used by the TECHNCIAL MANAGER to establish technical compliance for vehicles competing in the SCCA PRO RACING WORLD CHALLENGE series. The TECHNICAL MANAGER can also use, but is not limited to also using the following items to check compliance: Electronic Parts Catalog (EPC), Technical Information System (TIS), and the FIA/ASN Homologation forms (or equivalent documentation). The specifications within this form include all modifications that have been approved by SCCA Pro Racing specifically for the vehicle model(s) and year(s) listed on this page. The parts, specifications and assemblies used shall be those for the unmodified stock vehicle, those permitted within the Pro Racing Regulations (PRR) and/or within this VTS. If the stock parts, specifications and/or assemblies exceed the performance potential of those approved with this form, then the parts, specifications and/or assemblies used shall meet those listed within this form. Refer to SCCA PRR and Appendix A. for rules regarding all vehicle specifications not specifically listed within the VTS. The most current rules can be downloaded from the official website: www.world-challenge.com and look under the Competitors section for the latest Technical Bulletins, Participant Bulletins, and Appendix A. The Vehicle Technical Specification sheet is a permissive document. The exact configuration of any modification allowed within this VTS is subject to the approval of the TECHNCIAL MANAGER.. General Vehicle Description.A. Body Type: coupe.b. Engine Location: front.c. Drive Wheels: rear.d. Wheelbase: 2880mm.E. Induction Type: OEM is forced.f. Competition Weight: See Appendix A.G. Weight Distribution: See Appendix A 2. Engine 2.A.. OEM Engine Designation: LS 2.A.2. Maximum Displacement: 6.2 L 2.A.. Number of Cylinders: 8 2.A.4. Rev Limit: See appendix A 2.A.5. Rev Limit Method: ecu 2.A.6. Max. Compression Ratio: 0.7/ 2.A.7. Maximum Piston Stroke: 92.08mm 2.A.8. Restrictors: 2.A.8.a. Percentage Restriction: 2.A.8.b. Hole Diameter: See appendix A 2.A.9. Cylinder Firing Order: -8-7-2-6-5-4- 2.A.0. Direction of Engine Rotation: Clockwise 2.B. Cylinder Block 2.B.. Part : Casting P/N = 262766 Date Issued: /8/20 //204 Page: of 7
Vehicle: 20-20 Cadillac Class: GT 2.B.2. Cylinder Block Material: Aluminum 2.B.. Maximum Cylinder Bore: 0.50mm 2.C. Cylinder Head 2.C.. Part Casting P/N = 260082 2.C.2. Cylinder Head Material: Aluminum 2.D. Valve System 2.D.. Number of Valves Per Cylinder: 2.D..a. Intake: 2.D..b. Exhaust: 2.D.2. Maximum Valve Head Diameter: 2.D.2.a. Intake: 55.0 mm +/-. mm 2.D.2.b. Exhaust: 40.4 mm +/-.mm 2.E. Intake Port Dimensions 2.E.. At Intake Manifold Face 2.E..a. Height: 65.7 mm 2.E..b. Width: 2.E.2. Intake Port Work Allowed: yes 2.E.2.a. Depth From Face: 2.F. Exhaust Port Dimensions 2.F.. At Exhaust Manifold Face: 2.F..a. Height: 6.5 mm 2.F..b. Width 2.F.2. Exhaust Port Work Allowed: yes 2.F.2.a. Depth From Face:.9 mm 40.9 mm 2.G. Piston and Connecting Rod 2.G.. Connecting Rod Length: 2.G..a. Stock: 54.9 mm 2.G..b. Approved: See engine misc 2.G.2. Reciprocating Assembly Mass: 2.G.2.a. Stock: 20 g 2.G.2.b. Minimum: See engine misc 2.G.. Aftermarket Rods Allowed: yes 2.G.4. Aftermarket Pistons Allowed: yes 2.H. Camshaft 2.H.. Part 26206: General or 2.H.2. SCCA Profile Motors 2.H.. Rocker Arm Ratio:.7: 2.H.4. Valve Actuation: Pushrod 2.H.5. Type of Cam Follower: Roller Lifter 2.I. Crankshaft 2.I.. Part 2597569: General Motors 2.I.2. Stock Mass: 50.5 lbs 2.I.. Minimum Mass: 4.5lbs -.5 lbs per rule book See engine misc 2.J. Flywheel 2.J.. Stock Ring Gear Diameter: 55.6 mm 2.J.2. Flywheel Weight: 2.K. Forced Induction Intake System 2.K.. Turbocharger Manufacturer and Model: 2.K.2. Supercharger Manufacturer and Model: 2.K.. Compressor Inlet Diameter: 2.K.5. Compressor Pinwheel Inlet OD: 2.K.7. Maximum Boost Pressure: 2.K.8.a. Number of Intercoolers: 2.K.8.c. Intercooler Dimensions: 2.K.9. Permitted Modifications 2.K.0. Required MAP Sensor Location: 2.K.. Turbo Compressor Map: na na 2.K.4. Number of Compressors: 2.K.6. Turbine Pinwheel Inlet OD: 2.K.8.b. Intercooler Locations: Date Issued: /8/20 //204 Page: 2 of 7
Vehicle: 20-20 Cadillac Class: GT 2.L. Intake Manifold 2.L.. Part 2602477: General Motors 2.L.2. Stock Port at Cylinder Head Face: 2.L.2.a. Height: 6.4 mm 2.L.2.b. Width: 2.L..a. Allow Port Match to Head: Yes 2.L..b. Port Matching Depth: 2.L.4.a. Throttle Body Bore Dia.: 90 mm 2.L.4.b. Throttle Body Part 260509 2.L.5. Number of Throttle Bodies: 2.L.6. Butterflies per Throttle Body: 2.L.7. Intake Manifold Material: Composite 2.L.8. Manifold Pieces: 2.L.9.a. Intermediate Port Matching Allowed: yes 2.L.9.b. Depth from Face: 2.M. Required Engine Seal Locations 2.M.. Valve Cover Seal #: 2.M.2. Oil Pan Seal #2: 2.N. Engine Miscellaneous: "Race" spec components substituted for "stock engine" components to improve Engine reliability: - Cylinder Head Assembly: General Motors P/N 88958752. Combustion Chamber Volume = 62.5 cc - intake valve supplied with cylinder head, is titianium part # 2605524 - exhaust valve supplied with cylinder head, is hollow stem steel valve part # 2605525 - intake port volume 268cc +/- % - exhaust port volume 88cc +/- % - Piston & Pin Assembly: Mahle P/N 772-000/0. Compression Ration = 2.0: - Connecting Rod Assembly: Carrillo P/N GM-BKTLS-OHT-6250B6S. Length = 58.75 mm NOTE: Mass of Reciprocating Assembly (Piston, Pin, Rings, Connecting Rod) = 069 g - Camshaft: Competition Cams P/N 268R/268R HR0 - Crankshaft: Bryant Racing P/N 2968-GMWC. Mass = 4.5 lbs (-.5lbs per rule 2.4.5..) - Throttle Body Assembly: UMI p/n GM-PAX 0649. 90 mm - allow Aluminum main bearing caps, billet lifter valley, Billet rear main seal -Traction control and launch control permitted 29.6 mm. Drivetrain.A. Transmission.A.. Number of Forward Speeds: 6.A.2. Manufacturer: Xtrac.A.. Gear Ratios:.A..a. st:.0.a..b. 2nd: 2.54.A..c. rd:.64.a..d. 4th:.5.A..e. 5th:.50.A..f. 6th:.00.A.4. Gear Shift Pattern: sequential.a.5. Gear Engagement: Dog.B. All Wheel Drive System.B.. Transfer Case Manufacturer and Model No.:.B.2. Center Differential Type and Manufacturer:.C. Final Drive.C.. Axle Ratio:.0 drop gears.045 /..D. Drivetrain Miscellaneous Xtrac 559 6 Speed Transmission Step gear and change gear ratios to be supplied NA NA Date Issued: /8/20 //204 Page: of 7
Vehicle: 20-20 Cadillac Class: GT No lift shift Xtrac 247 Final Drive with.0 Ratio Quarter Master assembly containing bell housing, ring gear, and starter (p/n: 957790) Tilton 4 disc clutch / pressure plate p/n:67-004-h6 Tilton clutch disc pack p/n: 6440-9-A-CCC-6 PME adapter p/n 8P-00 PME Bellhousing p/n 8P-2000-0 standard Bosch Motorsports ABS M4 system, 4. Suspension 4.A. Suspension Type: 4.A.. Front: Double A-Arm 4.A.. Rear: Multi-Link 4.B. Suspension Miscellaneous The following part numbers are from Pratt and Miller The replacement steering rack was allowed in September 200 Front upright assembly p/n: 8E-000(L&R) Front upper control arm p/n: 902-E-000 Front cradle p/n: 8E-800 Rear trailing arm p/n: 902-F-4000 Rear cradle p/n: 8F-8000 Bishop/PME steering rack p/n J-0200 Rack is repositioned forward and up a total of 8.5 mm due to clearance Note: the front and rear cradles are production pieces modified for reduction in ride height. 5. Chassis 5.A. See Technical Department for information 5.B. Chassis Miscellaneous The following changes are for safety, service, crash protection and to allow the rule specified.0 inch minimum ride height Transmission access panel in the transmission tunnel Bolt in X brace extending beyond the rear axle Transmission tunnel is a production appearing replica Rocker bottom pinch flange and sled rails are trimmed and capped Rear chassis rails are raised 0.6 mm to allow for fitment of OEM ride height modified rear cradle Firewall is moved rearward 04 mm for engine location and fitment of OEM ride height modified front cradle. Engine set back measured from rear face of engine Block to Center line of rear axle is 28mm 6. Body 6.A.. Stock Coefficient of Drag:.6 Cd 6.A.2. Total Frontal Area: 4.4 m^ 6.B. Maximum Body Overhang: 2.B.. Front: 2.B.2. Rear: 6.C. Stock Body Materials: Steel body w/ non metallic front and rear fascias 6.D. Maximum Body Width at Front Wheelhouse: 887mm Date Issued: /8/20 //204 Page: 4 of 7
Vehicle: 20-20 Cadillac Class: GT 6.E. Maximum Body Width at Rear Wheelhouse: 6.F. Permitted Rear Wing Design: 6.F. Body Miscellaneous: The following parts are Pratt & Miller carbon fiber parts Hood p/n 8A-000 Trunk p/n 8A-0600 Front Fascia p/n 8A-0700 Front splitter Under-wing p/n 8A-200 890mm Hood Louvre p/n 8A-000 Front Fender p/n 8A-0200 L/R Door p/n 8A-0400 L/R Rocker p/n 8A-0500 L/R Rear Fender p/n 8A-00 L/R Rear Fascia p/n 8A-0800 Dash p/n 8A-500-0/02 L/R Console p/n 8A-500-0 Rear wing p/n 8A-200 Radiator exit duct allowed New rear stock appearing lower rear fascia p/n # 8A-080-02 Closeout panel p/n# 8A-080-0 Date Issued: /8/20 //204 Page: 5 of 7
Vehicle: 20-20 Cadillac Class: GT Camshaft Profile SCCA Profile Vehicle: Intake Lobe Cam Lift Duration Intake Lobe (in) ( ).00 294.54.020 279.57.00 269.7.040 260.77.050 25.58.060 247..070 24.24.080 25.75.090 20.56.00 225.56.50 202.5.200 78.82.250 5.46.00 24.0 Maximum Lift: 0.97 Cam Lift (in) Date Issued: /8/20 //204 Page: 6 of 7
Vehicle: 20-20 Cadillac Class: GT Exhaust Lobe Cam Lift (in) Exhaust Lobe Cam Lift (in) Duration ( ) Open Close Area 0.00 0.24 0.020 292.57 0.00 280.70 0.040 27.9 0.050 26.48 0.060 256.54 0.070 250.2 0.080 244.7 0.090 28.88 0.00 2.68 0.50 209.46 0.200 85.5 0.250 59.42 0.00 28.9 Maximum Lift: 0.97 Permitted Cam Tolerances Camshafts used for this car must meet the specifications above within the following tolerances: Duration at the seat (From 0.020 lift to 0.00 lift) +/- 6.5 degrees Duration on flank (From 0.00 lift to 0.00 before maximum lift) +/- 4.0 degrees Duration over nose (From 0.00 before maximum lift up to maximum lift) +/- 6.0 degrees Maximum Lift (This tolerance applies to maximum lift only) +/- 0.005 in (0.27 mm) Date Issued: /8/20 //204 Page: 7 of 7