#37051 Create ruleset that allows GTL cars to run in FP

classified in GT Classes based on their competitive potential. The purpose of this amendment is to provide the rules
classifications for previous GT-Lite cars that intend to compete in the F-Production class. The Club may alter or adjust
specifications and require, permit, or restrict certain specific components to equate competitive potential. The
SCCA does not guarantee the competitiveness of any car.
F.2. INTENT
It is the intent of these rules to allow modifications useful and necessary in the construction and preparation of an
extremely high performance road racing vehicle. It is understood that such a vehicle can be updated and/or
changed from marque-to-marque, based on member interest and manufacturer incentive. With this in mind, the
Club will use the following guidelines in the determination of the suitability for classification of cars within this
Appendix in the GT Category:
1. Basic vehicle size, shape, engine displacement, and cylinder head design of the standard and/or alternate
engine(s).
2. Member interest.
3. Manufacturer interest and potential support to competitors.
4. Vehicle production quantities of no less than 3000 units of the specified make/model within a twelve (12)
month period, all such units being approved by the EPA and DOT for sale in the United States (Production
Cars that have been reclassified into the GT Category need not meet minimum production quantities).
F.3. SPECIFICATIONS
The SCCA shall publish this Appendix the GT Category Specifications (GTCS) containing recognized specifications for
each car eligible to compete in F Production with a car previously classified in GT-Lite the GT Category during the
calendar year. Cars shall be listed according to the manufacturer’s make and model designation. In the case of
doubt involving specifications not adequately described in this Appendix the GTCS, Scrutineers/Stewards may refer
to maintenance manuals, spare parts books, general catalogs and performance catalogs published by the vehicle
manufacturer, MVMA specifications, and FIA Homologation Certificates for the make and model, or may inspect
other cars of the same make and model.
1. Cars log-booked for GTL Competition are eligible to run in F Production via this Appendix. GT Category
automobiles shall be divided into Classes based on relative performance as follows: GT2, GT3, and GTLite.
2. Cars may be updated or backdated within the specifications of the recognized make and model as listed on the
Approved Automobile List in this Appendix of the GTCS, or as listed on a single GT Specification Form line in
this Appendix of the GTCS. Any classified engine may be used in a classified chassis within the same
manufacturer as shown on the specification line.
3. Cars shall meet or exceed their minimum specified weight, as listed in this Appendix the GTCS, as qualified
or raced, with driver.
4. No permitted component/modification shall additionally perform a prohibited function.
Appendix N: GT-LITE CATEGORY SPECIFICATIONS for inclusion into F-PRODUCTION
5. Turbocharging/supercharging is not permitted unless listed on the spec line.
6. Construction of tube frame cars is permitted. Standard maximum track dimensions for all cars is 60.0”
Front & Rear, unless otherwise noted., are as follows:
GT-2 64.0” F & R
GT-3 / GT-Lite 60.0” F & R
7. Automatic Transmissions (10 forward speeds max.) are allowed in GT2 with a 100# weight penalty.
8. Current FP spec line cars may compete in GT3 as long as they maintain their full FP rule set.
F.4. GT Cars registered as GT cars prior to January 1, 1990.
All GT cars registered as GT cars prior to January 1, 1990 shall use the manufacturer’s original engine location,
i.e., front, mid, rear; drive location, i.e., front or rear, and type of front and rear suspension, i.e., MacPherson
strut, double A-arm, live axle, semi trailing arm, etc., unless authorized by the GTCS for a specific make and
model.
Front-engined GT cars registered as GTcars prior to January 1, 1990 may be converted to Section F.2.,
specifications, but shall meet ALL specifications of Section F.2.
F.5. GT cars registered as GT cars after January 1, 1990.
All front engined GT cars registered as GT cars after January 1, 1990 shall utilize McPherson strut or double A-arm
front suspension. A-arm front suspensions shall have the shocks attached to the outboard end of an upper or
lower control arm. Rocker arms, push-pull rods, etc., are prohibited. Front wheel drive cars may convert to rear
wheel drive. Cars classified per this Appendix in GT2-Lit e that retain the original front wheel drive (FWD)
configuration may retain the original type of rear suspension with no weight penalty or use a beam axle.
Cars classified in GT2-Lite running front engine, rear wheel drive (RWD) may use independent rear suspension (IRS),
by choice at a weight increase equal to 1.25% of the car’s specified weight.
All GT cars registered as GT cars after January 1, 1990 or updated to Section F.2. specifications shall utilize left side
driver placement.
Disenfranchised small bore GT2 cars will be allowed classification in GT3 “In GT2 spec” on a case by case basis but will
be classified with the appropriate SIR and GT3 weight + 150 lbs. to offset any advantage in the wider wheel/tire, track
and wing width. Max wheel/tire 16.0”. Cars must have a GT2 logbook issued prior to 1-01-2013
F.6. Safety Equipment required on all cars.
a. Bulkheads
1. A metal bulkhead shall separate the driver/front passenger compartment from the compartment
containing the fuel cell. The fuel cell, cap, filler neck, and all fittings shall be isolated so that in case of
spillage, leakage, or failure, fuel will not reach the driver. The bulkhead separating the driver/ passenger
compartment from the fuel cell shall not be above the bottom of the rear window and the bottom of the
side/quarter windows. An additional vertical, transverse bulkhead is permitted behind the driver. It shall
be located above the mandatory vertical bulkhead and shall allow the driver adequate vision to the rear.
It is recommended that this additional bulkhead be made of a clear, transparent polycarbonate material.
b. Fuel Cells
A safety fuel cell complying with GCR Section 9.3 Fuel Cell Specifications, shall be installed. All fuel cell vents shall
incorporate check valves to prevent fuel spillage. Dry-break refueling couplings and discriminator valves may be
installed, provided they do not extend beyond the bodywork. The use of a fuel cell is required unless the stock fuel
tank is located between the axle centerlines and within the main chassis structure (e.g. frame rails). Spec line
allowances will be added on a case by case basis.
c. Windows
1. Windshield safety clips and rear window safety straps shall be installed on all closed cars. Three (3) clips (3
inch x 1 inch x 1/8 inch) shall be bolted or riveted to the body at the top of the windshield. Two (2) clips (3
inch x 1 inch x 1/8 inch) shall be bolted or riveted to the cowl and extend over the bottom edge of the
windshield. Clips shall be spaced a minimum of twelve (12) inches apart. The rear window shall be secured
with two (2) metal straps (1 inch wide x 1/8 inch thick) bolted or riveted to the body at the top and bottom
of the rear window. Polycarbonate windshields such as Lexan are allowed. Alternate windshields must be
of 6mm minimum thickness. Alternate mate- rial windshields must be identical in size and curvature to
the original glass component. Alternate material windshields must have in addition, three (3) inner
supports to prevent the windshield from collapsing inward. These supports must be 0.75” by .125”
minimum straps of aluminum. Spacing between these inner supports must be six (6) inches minimum. In
place of clips, polycarbonate windscreens may be mounted using a fastener spaced a minimum of
every 12 inches across the top and sides, with a minimum of four across the bottom. Alternatively, the
bottom may be captured in a channel. No clips or straps are required if bonded-glass factory windshields
and/or rear windows are attached to chassis per original specifications (i.e., glass-bonding adhesive).
3. Open cars must remove the windshield glass, door window glass, quarter window glass, rear glass, vent
glass, frames/channels and all mounting brackets. Window winding mechanisms can be removed. A
replacement windshield must be installed. The replacement windshield must be fitted within the vertical
planes of the front most and rear most elements of the stock windshield and frame. The replacement
windshield must not exceed the height or width of the stock windshield and frame. Any portion of the
windshield that is in the driver’s line of sight, must be constructed of a clear material. No part of the
replacement windshield can be constructed of glass.
4. Ducts may be installed in the side windows or window openings for the purpose of supplying cooling air
to the driver and/or differential/transmission coolers and/or the rear brakes. Air passing through the
differential/transmission coolers may be exhausted through an opening identical in size and location to the
rear license plate frame.
F.7. Authorized Modifications
The following modifications are authorized on all GT-2, 3, and GT-Lite cars classified via this Appendix.
Modifications shall not be made unless specifically authorized herein. No permitted component/modification shall
additionally perform a prohibited function.
a. General
1. It is not permitted to make any changes, alterations, or modifications to any component produced by the
manufacturer, unless specifically authorized by these rules, or required by the GCR.
2. Any springs (including torsion bars) may be replaced by others of unrestricted origin, unless specifically
prohibited by these rules.
3. Where alternate suspension and/or drivetrain equipment is authorized, modifications to the car/chassis are
permitted to install authorized equipment, provided the modifications serve no other purpose.
4. All component parts of the bodywork, such as hood, doors, fenders, deck lid, rocker panels, wind- shield
surround, roof, etc., may be lightened or replaced by ones of alternate materials, provided the shape, size,
and relative position is identical to the original or approved alternate. The original size, angle, and relative
position of the windshield shall be maintained. Convertible tops, sunroofs, and removable panels shall
meet GCR Section 9.3 Detachable Panels/Sunroofs.
Vents may be added to the roof panel or rear window for the express purpose of venting the driver’s
compartment. There may be no more than 12 openings with a total area of not more than 24 square
inches.
5. Spare wheel and tire shall be removed.
6. Glass and/or plastic headlights, front parking lights, front signal lights, lenses, and bulbs shall be removed.
Headlight openings shall be covered with a wire mesh screen or panel having the same contour as the
original lens, mounted so that the headlight bezel/rim remains in place, maintaining the standard
appearance of the Production automobile. Side marker light assemblies shall be removed and the
resulting openings covered with a plate whose dimensions do not exceed those of the original parts; side
marker lights that are an integral part of the taillight assembly cannot be removed. Other lighting parts
and operating mechanisms may be removed. In the case of pop-up headlights, the entire assembly may
be removed and the opening covered with a screen or plate (as above, without the headlight bezel/rim
requirement) which provides a stock appearance. It is not permitted to relocate the standard headlight,
parking light, signal light, etc., openings. Traditional GT cars only. Not allowed with any “Spec Car, GT2-ST,
or any other added non Traditional GT car. Taillights shall be in the original location and may be the original
style/type of taillight for the make, model, and year of car. A rear body panel having the same contour as
the original lens area and in the original location, may be fitted with a tail-light graphic of the original
style/type frame/lens adhered to it. If side marker lights are an integral part of the tail-light assembly they
must be represented by the panel graphic. These panel/graphics shall have a functioning red LED lamp
assembly fitted through them on both sides of the car to serve as brake lights. A 15-watt or equivalent rain
light may be included with-in this LED assembly or may be a separately mounted single or dual LED
assembly.
Ducts from headlights, front parking lights, and front signal lights in the front of the car may be used for
ducting air to the engine, front brakes, and/or oil cooler(s). These ducts may pass through interior panels
for this purpose. The cross section area of a single duct shall not exceed the cross sectional area of the
original (single) headlight.
b. Chassis and Bodywork
The purpose of the following rules is to maintain recognizable external features of the manufacturer’s make and
model, while providing necessary safety and performance modifications.
Restrictions regarding external body shape and use of belly pans are aimed at preventing attempts to obtain
ground effect or streamlining. Provisions in the rules permit one-off chassis and frames, to reduce the cost of
building and repairing GT cars, not to permit high technology (streamlining and/or ground effects). Semi-
monocoque or monocoque construction is prohibited.
1. The external shape of the body cannot be changed, except when specifically authorized. Stan- dard grills,
window openings, or approved facsimiles shall be retained. All external trim and model identification may
be removed. Misalignment or modifications to create ventilation where none previously existed are
prohibited. One piece front and one piece rear bodywork is allowed. Rocker panels and doors may be
parted and/or integrated with associated body panels. Rocker panels of an alternate material may be a
flat vertical panel having the same dimensions as the original component when viewed from the side.
Overall width of the vehicle/rocker panel measured at the door sill must remain stock. Roof/A-pillars shall
be separate pieces. The cowl trim panel may be modified or removed. GT2 only: Four (4) hood/fender
louvered panels are allowed. Total maximum area of panels shall not exceed 600 sq. inches with a
minimum of five (5) slots for each panel. All louvers must be mounted in front of the windscreen.
2. Chassis, frame, or subframe may be lightened, reinforced, or replaced, provided components and
attachments are not relocated, except where specifically permitted. Reinforcing does not authorize the use
of belly pans forward of the firewall, or aft of the front edge of the rear wheel opening. There shall be no
pans, whether factory supplied or otherwise, between the spoiler pan and the floor pan nor between the
floor pan and the floor behind the rear wheel opening. The floor behind the rear wheel opening shall be
flat and follow, but not exceed, the line of the rear fender bottom. Only the fuel cell container may
protrude or extend below this plane. There shall be no pans, whether factory supplied or otherwise,
between the spoiler pan and the floor pan nor between the floor pan and the floor behind the rear wheel
opening.
3. The firewall and floor may be replaced with aluminum alloy or steel. Firewalls may be modified or notched.
4. Bumpers may be removed providing all projecting hardware is removed except when it (they) are an
integral part of the bodywork, in which case it (they) may be replaced with replica(s) of different
material. Non-integral bumpers may be replaced with a replica of alternate material or removed.
Bumper bracket holes in the bodywork may be covered provided such covering serves no other purpose.
5. All standard production seats and seat backs shall be removed. The driver’s seat shall be replaced with a
one-piece bucket-type race seat. Such seat shall be installed so that a second seat of the same dimensions
could be simultaneously fitted to the passenger’s side of the car (no center seating).
6. Doors shall be pinned or otherwise positively fastened to prevent their opening in case of an accident.
Standard door hinges and latch mechanisms may be removed, but the doors shall be capable of being
opened or removed unless integrated into the bodywork. Interior door panels may be removed and the
door window slots may be covered. Pins or straps may be added to hood and deck lid to supplement or
replace the latches. Hood and deck lid hinges may be removed.
7. All driver and front passenger door window glass shall be removed. Window cranks and mechanisms may
be removed. Rear quarter, rear side, and rear windows may be of transparent (clear) polycarbonate
material, minimum thickness 3mm, but shall remain in the same position in the frame or opening as the
original glass it replaces; rubber molding optional. Rear windows/hatch- backs and deck lids shall be
completely closed. No bumper blocks or other means of poor alignment of bodywork will be permitted.
Rear quarter (side) windows may be run in their original open or closed position.
8. Fenders may be flared for tire clearance, provided their shape and opening contour, in the hori- zontal
projection, is similar and proportional to the original opening. Rear doors on 4-door automobiles may be
considered part of the fender for purposes of fender flaring. The tire shall not extend beyond the fender
openings at the highest point of the tire. The rear fender flares on GT-2 cars may extend forward into the
door, no more than 26 inches from the rear axle centerline (GT-2 only). Wheel opening location may be
altered in accordance with the allowable wheelbase tolerance in order to maintain vehicle’s stock
appearance. Ventilation openings, other than those which are standard production on the recognized
model, are prohibited.
9. Front and rear inner fender panels may be altered, replaced, or removed provided there are panels
providing total separation between driver compartment and wheel wells.
10. Replacement, addition, or removal of accessories (gauges, switches, indicators, etc.), or other interior
modifications for driver convenience, or to permit installation of required safety equip- ment, is
authorized provided such modifications have no influence whatever on the mechanical performance of
the car. Such modifications do not include the substitution or replacement of any bodywork or chassis
component except those specifically authorized by these rules. Floor mats and all interior trim shall be
removed.
11. A spoiler may be fitted to the front of the car. It shall not protrude beyond the overall outline of the car as
viewed from above, except as follows:
• GT3: a front splitter may extend up to 2 inches.
• GTLite: a front splitter may extend up to 2 inches.
In all classes, the The spoiler shall not extend aft of the forward most part of the front fender opening
(cutout), and shall not be mounted more than four (4) inches above the horizontal centerline of the
front wheel hubs. The spoiler shall not cover the normal grill opening at the front of the car. An
intermediate mounting device may be used on cars whose front bodywork is above the four (4) inch
minimum. Openings are permitted for the purpose of ducting air to the brakes, radiator, airbox and/or
oil cooler(s); equal openings may be placed in the standard lower front panel directly behind openings
placed in the spoiler. When bumpers are retained, the spoiler and bumper shall appear to be two
separate parts. Spoiler “pans” are only permitted forward of the leading edge of the front wheel
openings and shall be flat and follow, but not exceed, the line of the front fender/ spoiler bottom.
12. A spoiler or a Club Racing Board specified rear wing for GT 3 may be fitted to the rear of the car. Note:
OEM rear spoilers and wings are not permitted unless specifically listed on the vehicle’s specification line.
If a spoiler is used, it shall be contiguous with the bodywork and shall comply with the following:
A. Height (max): six (6.0) inches (GT3) or five (5.0) inches (GT-Lite) measured from the body- work along
the face of the spoiler from the point of attachment to the top of the spoiler. In the case of a spoiler
with a curved top edge conforming to the shape of the bodywork (rear- view), the measurement is to
be made perpendicular to the tangent of the body at the point of attachment. In the case of a spoiler
mounted with a vertical mounting flange on the bodywork, the measurement shall be made ignoring
any slight amount of mounting flanges (see below) exposed due to the curvature of the rear bodywork
at the point of attachment.
B. Width and Overhang: If roof mounted, no wider than the roof at its mounting point when viewed from
above the car. Mounting to be no further rearward than the forward most part of the rear window. If
rear mounted, no wider than the body, excluding fender flares, from the forward most part of the
spoiler (or mounting flange) rearward. Shall not extend rearwards of the rearmost extremity of the
bodywork for the entire width of the car (when viewed vertically from above the car at any point, the
spoiler shall not protrude beyond the bodywork).
C. Mounting: Spoilers shall be strong enough to be self-supporting. A mounting flange no greater than
one and one-half (1-1/2) inches wide, contiguous with the bodywork, (either forward facing on the
top surface of the bodywork or downward facing on the rear surface of the bodywork) shall be
employed. Supplemental forward bracing may be added in the form of two (2) rods, mounted at least
ten (10) inches inboard from the ends of the spoiler. Rear supports may be added.
D. Configuration: The spoiler shall be a single plane spoiler (a straight line in any vertical cross section)
uniform in height from the bodywork with no more than 1/8” gaps/openings below the spoiler to
facilitate imperfect mounting. The gaps/ openings are to be included in the overall height of the
spoiler. Only enough curvature (in a fore and aft direction as viewed from above) shall be permitted to
facilitate mounting. The use of fences, end rails, Gurney flaps, or other forward facing lips or
aerodynamic devices is prohibited.
NOTE: O.E.M. rear spoilers are not permitted unless specifically listed on the vehicle’s speci- fication
form.
If a Club Racing Board specified wing is used (GT3 only), it shall comply with the following:
E. A single element, single plane airfoil up to a maximum chord length of 10.75 inches.
A maximum 0.50 inch Gurney flap is allowed at the trailing edge of the wing element. The flap must be
mounted 90 degrees to the upper wing surface. No air may pass between the flap and the wing.
The wing end plates may be no more than 64 square inches. No portion of the wing element or tab
may extend beyond the perimeter of the endplate. The endplates must be mounted parallel to the
vehicle centerline, and must be perpendicular to the ground. Endplates must be flat, with no
curvature or Gurney flap.
GT3: The maximum width of the entire wing assembly (wing element, endplates, Gurney flap, and
mounting hardware) is 64.00 inches, but no wider than the rear body width including fender flares.
F. Wing mounting
GT3: The entire wing assembly must be mounted below the highest point of the roof or roll cage
main hoop whichever is higher measured at the highest point.
GT3: The trailing edge of the wing assembly must be located within an area not forward of 6” forward
of the rear most bodywork and not rearward of the rearmost bodywork. The rearmost bodywork is to
be measured at the vehicle centerline.
Two wing mounting posts must be used, with each one located between 2”-20” inboard from the end
of the wing. The exposed portion of the wing mounting posts shall not exceed 85 square inches
each. Curved brackets will be measured as if they’re in a flat plane as viewed from the side.
Mounting brackets are to be included in measurement.
The maximum wing angle from horizontal is 30-degrees.
13. GTL Wing Rules
A. The maximum width of the entire single element, flat plane wing assembly (wing element, endplates,
and mounting hardware) is 56.0 inches, but it may be no wider than the bodywork including fender
flairs. The maximum chord is 8.0 inches. Wing endplates may be a maximum of 64 Sq. inches. Endplates
must be flat, with no curvature or Gurney flap. A maximum 0.5- inch Gurney flap may be employed.
B. The wing shall be mounted with two brackets. Each mounting bracket shall attach to the wing at least
2.0 inches inboard of the endplates. The brackets may protrude through the trunk/ deck lid to allow
the brackets to be fastened together and/or to the chassis of the car beneath the lid.
C. The entire wing assembly must be mounted below the highest point of the roof or roll cage main hoop
whichever is higher measured at the highest point.
D. The trailing edge of the wing assembly must be located between 6.0 inches forward of the rearmost
bodywork and the rearmost bodywork as measured along the vehicle longitudinal centerline.
E. Cars with a wagonback/notchback/hatchback style body must have the entire wing positioned
between 6.0 and 28.0 inches of the rearmost bodywork as measured along the vehicle longitudinal
centerline, and a maximum of 4.0 inches above the highest point of the roof. For this subsection, a
wagonback/notchback/hatchback style body (or variations of these) is a car in which the rear edge of
the roofline is no more than 28.0 inches forward of the rearmost bodywork as measured along the
vehicle longitudinal centerline.
F. Two wing mounting posts must be used, with each one located within 2”-20” inboard from the end of
the wing. The exposed portion of the wing mounting posts must not exceed 85 square inches each.
Curved brackets will be measured as if they’re in a flat plane as viewed from the side. Mounting
brackets are to be included in the measurement. Openings in the side view of the wing mounts are not
included in the sq. inch limit.
14. GTLite front splitter: A front splitter may be added that is a flat single-plane. The splitter shall be mounted
flat. The splitter must not extend laterally any further than the widest point of the front fenders. The
splitter must have no vertical deviations. Additionally, a maximum of four (4) rods or cables may be used to
support the front, and/or the sides of the splitter. A single-plane vertical close- out panel may be used to
bridge any gaps between the front fascia and splitter.
15. GT2 Aerodynamics
A. Front Air Dam
1. A front spoiler/air dam may be added. It shall not protrude beyond the overall outline of the body
when viewed from above perpendicular to the ground, or aft of the forward most part of the front
fender opening.
2. The spoiler/air dam shall be mounted to the body and may extend no higher than four (4) inches above
the horizontal centerline of the front wheel hubs. The air dam shall have no support or reinforcement
extending aft of the forward most part of the front fender wheel opening.
3. The minimum ride height of the air dam is 2.0 inches.
4. Openings are permitted for the purposes of ducting air to the brakes, cooler(s), and radiator(s).
B. Under tray
1. An under tray may be added. The under tray may close out the underbody from the leading edge of
the approved bodywork (including air dam) back to the centerline of the front axle.
2. The minimum ride height of the under tray is 2.0 inches.
3. Regardless of front or rear engine placement, an additional front under tray (close out panel) is
allowed from the floor pan forward to the rear of the rear of the front wheel opening.
C. Splitter
1. Definition: A horizontal, single-plane aerodynamic device attached to the lower front of the
vehicle, protruding forward. It is intended to divert air and produce down force through vertical
pressure differential. A splitter shall have no vertical deviations.
2. A front splitter may be added. A maximum of 4 rods or cables may be used to support the front
and/or sides of the splitter. No other material(s) may be used external to the body to support the
splitter.
3. The front splitter must not extend more than 5.0 inches past the forward most surface of the
original or approved bodywork as viewed from above for the entire profile of the splitter.
4. No part of the splitter shall extend laterally any further than the widest point of the outside sidewall
of the front tires with the wheels pointed straight ahead.
5. The splitter may have vertical deviations, fences, etc., only if they are part of the production
bodywork for street use.
6. The minimum ride height of the front splitter is 2.0 inches.
D. Rear Wing
1. The wing shall be mounted to the trunk lid upper surface / deck lid upper surface with 2 mounting
brackets. Each mounting bracket shall attach to the wing at a point that is between 4.0 and 30.0
inboard of endplates, including the entire exposed vertical struc- ture. The wing, and the portion
of the mounting brackets located externally to the trunk lid upper surface / deck lid upper surface,
may only be reinforced by a diagonal strut having no aerodynamic effect, and/or by affixing the
external parts of the brackets to internal parts of the brackets within the trunk/cargo area. The
internal parts of the brackets may protrude through the trunk lid upper surface / deck lid upper
surface to allow the two parts of each bracket to be fastened together. The exposed side view
portion of the wing mounting brackets / posts shall not exceed 100 square inches each. Curved
brackets / posts will be measured as if they are in a flat plane as viewed from the side. Mounting
brackets / posts must have no additional aerodynamic purpose.
2. Rear Wing: Wings shall be a single element with a maximum chord length of 12.00 inches, including
any Gurney flap.
3. No wing may exceed 72” in length. The entire wing assembly may be no wider than the widest
part of the car.
4. The entire rear wing assembly, including the end plates and any Gurney flap, shall be mounted
level with, or below, the peak of the roof.
5. The trailing edge of the rear wing may be mounted no further rearward than the center of the
rearmost part of the approved bodywork.
6. Wing end plates must not exceed 144.0 square inches each.
E. Additional Aerodynamics
1. Canards or dive planes are permitted up to 50 square inches (per canard) and two per side (max 4).
Vertical side fences permitted at a maximum of 0.75” from the canard surface. Canard surface
must be mounted to the front bodywork/spoiler with a maximum 1/16” gap allowance between
canard and bodywork.
2. Regardless of front, rear or mid-engine placement, flat underbody panels are permitted.
Underbody panels may start behind the front wheel openings.
3. An underbody close-out panel(s) may be used in the area behind the rear axle centerline. These
panels shall not alter the external appearance of the car when looking from the rear and sides of
the car (i.e. we want to have to lay on the ground to see them). If the produc- tion car uses
underbody trim pieces, the OEM trim pieces may be removed or replaced, but any close-out
panel(s) used may not visually hide any more of the mechanical compo- nents, when looking from
the rear and sides of the car, than the OEM trim pieces do. On rear engine cars, any close-out
panels shall not extend any further forward than the rear axle centerline. Cars with a fuel cell,
engine, etc. that extend down into external visual range shall fit the close-out panel(s) around the
component in such a way that it does not alter the external appearance of the car. Regardless of
front or rear engine placement, an additional rear under tray (close out panel) is allowed from the
floor pan rearward to the centerline of the rear axle.
F. Up to four hood/fender louvered panels are allowed. Total measurement area of panels shall not
exceed 600 sq inches with a minimum of five slots (louvers) for each panel. All louvered panels must
be mounted in front of the windscreen.
c. Suspension and Wheels
1. Wheelbase will be homologated on a case by case basis as requested by the manufacturer. Wheel- base
may be changed from -3” to +1” from printed stock dimensions in a fore/aft direction.
2. Suspension components may be reinforced, modified, or replaced as long as the type of suspension is
not changed from that authorized in this Appendix GTCS.
3. Suspension mounting points, including suspension springs, may be relocated.
4. Suspension springs may be replaced with others of unrestricted origin.
5. Modifications or substitution of hubs, bearing, spindles, axle shafts, universal B joints, flex joints, and CV
joints is permitted.
6. Addition or substitution of antiroll bars, camber compensating devices, and/or suspension stabi- lizers is
permitted. If these devices extend into the driver/passenger compartment, they shall be completely
sealed off by metal panels.
7. Suspension bushings and joints may be replaced by others of different material and/or design. Offset
bushings and spherical bearings are permitted, including adjustable type.
8. Steering arms, pitman arms, and steering linkage component parts may be modified, reinforced, or
substituted. The steering system may be changed and/or relocated.
9. The steering wheel may be replaced and rake of the steering column may be altered. A collapsible type of
steering column equivalent to Federal Motor Vehicle Safety Standard No. 204 is required in all cars
registered after January 1, 1983 and highly recommended for prior registered cars. GT cars registered
after January 1, 1990 or GT cars converted to Section F.2., specifications shall have left side driver
placement.
10. Substitute wheels of any type may be used. All four (4) wheels shall be of the same diameter. The
maximum wheel size is 13” X 7” unless otherwise noted on the vehicle specification line. Alternatively,
any wheel up to 15” x 7” may be used with a weight penalty equal to four percent of the car’s weight as
listed on the specification line. The minimum vehicle weight shall be rounded to the nearest pound.
except in GT2.
a. GT2 cars may run any tire/wheel combination provided that the tire does not exceed a maximum
cross section width of 12.0” in the front and 13.75” in the rear. GT2 cars using 15 x 7” wheels exclusively
may reduce the listed weight by 50 lbs. GT2 cars may run Hoosier DOT tires #46846 front,
P315/30ZR18 A7 and #46850 rear, P335/30ZR18 A7.
b. The maximum wheel size for GT3 cars is 15 x 7”. Alternatively: GT3 cars may run up to a maximum
17” x 9” wheel with a weight penalty equal to three (3) percent of the car’s weight as listed on the
specification line. The maximum vehicle weight shall be rounded to the nearest pound. Additionally:
Any wheel up to 18” with a maximum tire cross section of 12.0” and a maximum tire diameter of 26.0”
may be used with a weight penalty equal to five
(5) percent of the car’s weight as listed on the specification line. The minimum vehicle weight shall be
rounded to the nearest pound. A maximum brake rotor diameter of 13.0” may be used with
alternate wheels. Any racing tire including DOT is allowed in GT3. Cars using 15” American Racer
23.5-10.0-15, bias ply, non-belted tire may do so without the weight penalty.
c. The maximum wheel size for GTL is 13” X 7” unless otherwise noted on the vehicle specifica- tion line.
Alternatively, any wheel up to 15” x 7” may be used in GTL with a weight penalty equal to four percent
of the car’s weight as listed on the specification line. The minimum vehicle weight shall be rounded to
the nearest pound. Cars using 13” wheels may run 13” x 8” wheels, but only with American Racer 20.0-
8.0-13, bias ply, non-belted tires, without weight penalty. GTL cars using 15” wheels may run 15” x 10”
wheels, but only with American Racer 23.5-10.0-15, bias ply, non-belted, tire without weight penalty.
11. Shock absorbers: It is not permitted to alter the number of shock absorbers. The make of shock absorber
is free and its points of attachment may be moved. Shock absorbers may have load bearing capacity; e.g.,
gas filled or coil over. When using load bearing shocks, the original springs may be removed. GT cars
registered after January 1, 1990 or GT cars converted to Section F.2., specifications shall have the shock
absorber attached to the outboard end of an upper or lower control arm. Rocker arms, push-pull rods,
etc., are prohibited.
d. Electrical Systems
1. The electrical/electronic system may be modified or replaced provided an operating starter motor and
two (2) brake lights are retained.
2. Any distributor or transistorized ignition system (including crank triggered), firing the same number of
spark plugs as the original distributor, may be used.
3. Magneto ignition is prohibited unless listed in this Appendix the GTCS. Ignition wiring and spark plugs are
unrestricted.
e. Engine and Drivetrain/General
1. Exhaust manifold(s), header(s), tailpipe(s), and muffler(s) may be of unrestricted origin. The exhaust pipe(s)
and/or muffler(s) may be recessed into the floor panel and rocker panel. The exhaust may be recessed
into the bottom of the door or rear fender below a line seven (7) inches above the bottom of the rocker.
There maybe a maximum of two (2) such areas in the door or fender, with the maximum length for each
no more than seven (7) inches. Note that the exhaust outlet shall still be mounted as low as possible.
Exhaust opening(s) shall exit to the rear of the wheelbase center- line and away from the body.
180 degree headers: The passenger’s side floor pan may be raised not more than ten (10) inches or a
secondary floor may be installed at that level to accommodate the installation of the exhaust system and
muffler(s) provided such raising of the floor serves no other purpose. Exhaust may pass through the rear
bodywork no higher than the rear axle centerline.
2. Exhaust emission control air pumps, associated lines and nozzles, and EGR devices cannot be modified in
any way except that they may be completely removed. When air nozzles are removed from the cylinder
head, the holes shall be completely plugged.
3. Substitution or modification of the clutch and/or flywheel is permitted.
4. It is permitted to lighten, balance, or modify in shape, by tooling, the standard or optional components of
the engine and drivetrain, provided it is always possible to identify them as such. Material shall not be
added to these components unless specifically authorized by these rules.
5. Alternate engine and drivetrain components considered replacement parts, such as seals, bearings, valve
guides, pushrods, water pump (including electric), timing chains/belts and sprockets, nuts, bolts, studs,
washers, and gaskets are permitted. Bushings or offset keys of unrestricted origin may be installed.
6. The substitution of valve spring retainers and keepers is permitted. Valve springs are unrestricted
(including number) provided the type and location remain unchanged.
7. Generator (alternator), crankshaft, and water pump pulleys may be altered or replaced with others of
unrestricted origin. Any crankshaft vibration dampener is allowed.
8. Any oil pan (sump), oil pump(s), and/or pickups are allowed. Oil pump(s) shall be driven mechanically by
the engine. Dry sump systems are permitted. The oil tank shall be located within the bodywork. The oil
tank, cap, and all fittings shall be isolated so that in case of spillage, leakage, or failure, oil will not reach
the driver. Any oil filter(s) may be used.
9. Installation of any vent or breather on the engine, transmission, or differential is permitted (See “Oil Catch
Tanks”). Crankcase vacuum devices are prohibited, but a conventional dry sump system is permitted.
10. Any readily available manual transmission having no more than six (6) forward speeds in GT2 and five (5)
forward speeds in GT3 and Lit e and a functional reverse speed may be used, provided that it is fitted in
the same basic location used in the standard production automobile. Any shift linkage may be used. If a
sequential shift gearbox is used, the car must carry a weight penalty equal to 1.25 2.5 percent of the
weight as listed on the spec line. If a synchromesh engagement transmission is used, the weight may be
reduced by 1.25 percent of the weight listed on the spec line. A synchromesh gearbox is one having a
friction mechanism to allow engagement. Note: The minimum vehicle weight is to be rounded to the
nearest pound. Air, hydraulic or electric actuation of the gearshift mechanism is not allowed. For front
engine, rear drive cars requiring the transmission to be attached to the engine, the transmission front seal
shall be within twelve (12) inches of the back of the engine block. On front engine/rear drive cars, the
transmission front seal is that seal which is within 5” of the gear on the input shaft which meshes with the
foremost gear on the counter/layshaft.
A functional reverse is defined as “operable by the driver from his normal seated position and capable of
sustained movement of the vehicle, under its own power, in a reverse direction.” A driver-operated
device for locking out reverse gear may be added provided it does not prevent prompt engagement of
reverse in an emergency situation.
11. Heavy duty propeller shaft(s) and/or drive shaft(s) may be used. Steel retaining strap(s) shall be used to
prevent drive shaft failure from dropping or entering driver compartment.
12. Any axle tube, final drive housing, gear ratio, limited slip, or locked differential may be used. Final drive
units which permit ratio changes while the car is in motion are prohibited. GT cars registered after January
1, 1990 or GT cars converted to Section F.2., specifications, using the front engine/ rear drive configuration,
shall use a “closed tube” rear axle housing or may use independent rear suspension (IRS), by choice, at
weight increase equal to 2.5% of the car’s specified weight.
13. OEM body-engine-chassis combinations may run in their stock locations. If the factory chassis is altered
with respect to engine mounting or spindle location then engine location must comply with the following:
Engine location is defined such that the forward-most spark plug is within 1.0 inch of the front axle
centerline. Engine and transmission mounts may be of alternate shape and/ or material. Cars with engines
mounted longitudinal to the chassis MAY relocate the engine in a longitudinal, not lateral, direction within
the following restrictions: (Note: A tolerance of up to a 1.0 inch setback is allowed if the engine is
relocated.)
A. V8, V6, and V4 engines shall align the center of the foremost spark plug hole in line with the front
axle spindles.
B. In-line six (6) cylinder engines shall align the center of the first spark plug hole (from the front) in line
with the front axle spindles.
C. In-line four (4) cylinder engines shall align the center of the first spark plug hole (from the front) in
line with the front axle spindles.
D. Rotary engines setback from the front spindle centerline to the front spark plug is 4.5 inches.
E. The engine may be rotated about the crankshaft centerline (lean over) a maximum of fifteen
(15) degrees unless otherwise noted and shall not cause hood bulges.
14. Any transverse mounted engine may be rotated for axle/CV joint alignment. Any readily avail- able
transmission having a functional reverse and no more than five (5) forward speeds may be used, provided
it is mounted to the rear of the engine. All transverse engines may be rotated 180 degrees. A transverse
mounted engine may be rotated to a longitudinal position that places the crankshaft centerline on the
longitudinal centerline of the car (shall conform to all restrictions in Section 9.1.2.F.4.e). The engine may
be rotated about the crankshaft (lean over) a maximum of fifteen (15) degrees unless otherwise noted
and shall not cause hood bulges. Rear axle / suspen- sion per GTCS 9.1.2.F.2.
f. Engine, Reciprocating
1. Engines may be rebored a maximum of 1.2mm (0.047 inch) over the standard bore size listed in this
Appendix the GTCS. A cylinder block from any model from the same manufacturer which is of the same
material and dimensionally identical throughout, except for non-critical bosses, is permitted.
2. Crankshaft main bearing caps may be modified or substituted. Main bearing cap straps or girdles and/or
additional main bearing cap bolts may be used, provided that no material is added to the block for their
attachment.
3. The crankshaft may be replaced with another of the same basic material, but with no change in stroke
and provided the angles of the crank throws remain the same. The engine firing order shall remain
unchanged.
4. Connecting rods may be replaced with any connecting rod of steel (ferrous) material. Aluminum, titanium,
and non-metal connecting rods are prohibited, except where fitted as standard.
5. Any pistons and piston pins may be used.
6. Any camshaft(s) may be used, provided locations are (is) the same as standard.
7. Any cam followers may be used, except that roller cam followers shall not be used unless fitted as standard
equipment.
8. Any rocker arms and rocker assembly supports may be used.
9. Valve sizes are unrestricted except when limited by this Appendix the GTCS for specific automobiles.
Centerlines shall not be altered. Valves may be of alternate material; non-metal is prohibited.
10. Compression ratio may be altered by machining, using any head gasket(s) or elimination of head gasket(s).
g. Engine, Rotary Piston
1. The capacity of the working chamber(s) shall not be changed.
2. The eccentric shaft may be replaced with another of the same basic material, but no changes in
eccentricity or journal dimensions are permitted.
3. Rotor is unrestricted, providing the material and number of lobes remain unchanged.
4. Alternate rotor housings are allowed only as listed in this Appendix the GTCS for specific automobiles.
No changes are allowed in the epitrochoidal curve in alternate housing.
h. Engines, GT3 Turbocharged Built:
1. Engines up to 4 cylinders and 1800 cubic centimeters factory displacement are permitted with a single
turbocharger. Engines may be prepared in accordance with 9.1.2.f.
2. Turbo inlet restrictors designed per GCR Appendix F Technical Glossary definition of “Turbo Inlet
Restrictor” may be required; see GT3 Turbocharged Built Engines Table.. Swapping of turbo- chargers
between engine makes and models is prohibited.
3. All cars shall use the installed engine’s stock air throttling device (e.g., throttle body, carburetor) and
intake manifold, unless noted otherwise.
4. Compression ratio on spark-ignition engines is limited to 15.0:1.
5. Dry sump systems are permitted. The oil tank shall be located within the bodywork.
6. Factory turbocharged engines must run the stock turbo or any turbo from the following list:
A. KKK/Borg-Warner K04
B. IHI VF30, VF39, or VF48
C. Garrett GT2554R, p/n 471171-3
D. Borg-Warner EFR6258
GT3 Turbocharged Built Engines:
Engine
Displacement (cc)
Valves
/ Cyl. Restrictor Weight (lbs) Notes
<1400 4 33 mm 2100
1401-1850 4 34 mm 2250
1401-1850 4 35 mm 2350
i. Engines, GT3 Turbocharged OEM:
1. Engines up to 4 cylinders and 2000 cubic centimeters factory displacement are permitted. Engines must
remain in their OEM configuration.
2. Turbo inlet restrictors designed per GCR Appendix F Technical Glossary definition of “Turbo Inlet
Restrictor” may be required; see GT3 Turbocharged OEM Engine table.
3. Dry sump systems are permitted. The oil tank shall be located within the bodywork.
GT3 Turbocharged OEM Engines:
See Car and Engine Spec Lines
m. Cooling Systems
1. Cooling fan(s) may be modified, substituted, or removed. Electrically operated cooling fan(s) may be
installed, provided it (they) serve no other purpose. The use of any engine, transmission, and/ or
differential oil coolers(s) is (are) permitted provided it (they) are mounted completely within or under the
bodywork, but not in the driver/passenger compartment. Associated oil cooler pumps and lines are
permitted for the transmission and differential. Air ducts may be fitted to the oil cooler(s) as specifically
authorized herein.
2. Any water radiator is allowed, provided there are no changes in the exterior bodywork to accommodate
its use. It shall not be located in the driver/ passenger compartment. Separate expansion or header tank(s)
are permitted, provided they are mounted in the engine compartment. The heater core may be removed
entirely but not modified or replaced.
3. Sealing or shrouding the airflow area between the normal grill opening and the water radiator is
permitted.
4. On water cooled cars, thermostats may be modified or replaced with blanking sleeves or restric- tors.
5. Alternate fan and fan shroud are permitted on air cooled engines.
6. Radiator intake and brake openings may be covered with screen and/or taped as necessary to protect
the radiator and/or regulate air flow.
n. Fuel Induction System
All inducted air shall pass through venturi(s), maximum one (1) per cylinder or rotor.
1. Any air filter(s) may be used, or the filter(s) may be removed. Velocity stack(s) and/or air box(es) may be fitted. Air
may be ducted to the carburetor(s) provided the ducting is contained within the engine compartment and air is
supplied through normal openings in the bodywork (or as specifically authorized herein).
2. Any fuel pump(s) may be used and the location(s) may be changed. Fuel pump(s) shall not be located in the
driver/passenger compartment.
3. All fuel/oil lines passing through the driver/passenger compartment shall be steel or metal braided hose. Number of
fuel lines is unrestricted.
4. Carburetors:
A. Reciprocating engines: Carburetor(s) and intake manifold(s) are unrestricted except as limited in this
Appendix the GTCS for a specific make/ model. All cars with restricted carburetion are required to use
I.R. manifolds with no plenums or balance pipes unless using an SIR or otherwise restricted for specific
automobiles. Intake manifold(s) shall be attached to the head(s) without modification to the head(s).
B. Rotary engines: Carburetor and intake manifold are unrestricted except as limited in this Appendix the
GTC S for a specific make/model. All cars with restricted carburetion are required to use I.R. mani-
folds with no plenums or balance pipes, unless using an SIR. Intake manifold(s) shall be attached to
the end cover(s) or rotor housing(s) without modification to the end cover(s) or rotor housing(s).
C. No portion of the intake manifold(s) may extend into the intake ports (reciprocating and rotary
engines.)
D. Carburetors shall incorporate a butterfly-type throttle plate for engine speed control. For GTLite only:
Carburetors shall incorporate a butterfly or slide-type throttle plate for engine speed control.
E. Where Weber or Weber-type carburetors are specified and used, they shall retain their stan- dard
configurations of fuel distribution. This is to prohibit annular discharge carburetors.
F. Where Weber carburetors are specified, Weber-type carburetors may be substituted. The following
are approved Weber-type carburetors: Weber, Solex, SK, Mikuni, Delorto, Berg, and PMO.
5. Any car may utilize fuel injection, whether originally equipped with fuel injection or not. The following
restrictions apply.
A. Both method and manufacturer are open.
B. Intake manifold shall be of the individual runner type, unless using an SIR or otherwise notes on the
vehicle spec line. Cars using an SIR may use any manifold type.
C. Only butterfly-type throttle plates for engine speed control, one per cylinder or rotor, are permitted
if intake restrictors and/or chokes are specified on the vehicle specification line, the restrictors shall
be round orifices (unless otherwise specified) and located within four (4) inches of the throttle
butterfly. SIR location is unrestricted so long as all SIR criteria are met. Restrictors shall be a minimum
.060” thickness and of the specified diameter.
D. All inducted air for each cylinder must pass through the specified restrictor. Fuel injected cars, unless
otherwise specified, shall use the same individual venturi restriction size specified for a car using
carbureted induction.
E. The number of injectors shall be one (1) per cylinder (unless otherwise noted on the vehicle
specification line). Direct injection is permitted only if it came OE and must be installed using only OE
high pressure pump(s), hard and soft hoses and injectors.
F. Rotary engines may use two (2) injectors per rotor.
6. Supercharging/turbocharging is prohibited.
7. Any throttle linkage may be used.
8. Induction systems shall be equipped with a positive method of throttle closing by means of (an) external spring(s).
For GT3 and GTL (GTLite) only:
9. As an option, induction system “Chokes” may be used where a SIR is required. Said chokes shall be fitted to
each barrel of carburetor/throttle body and all airflow into engine must pass through them. Choke size will
be the same as listed SIR unless noted.
This option is for normally aspirated cars with SIRs only and does not apply to turbo cars with TIRs.
10. All 2.0 liter 4-valve non-turbo engines currently listed in GT3 shall be permitted to run without any
restriction (SIR or chokes) at 2060lbs.
j. Brakes
1. Any dual master cylinders and/or pressure equalizing/regulating device(s) are permitted. ABS braking
systems are allowed if shown on the individual Spec Line.
2. Servo-assist systems are unrestricted.
3. Backing plates/dirt shields may be ventilated or removed. Brake air ducts may be fitted within the
provisions of these rules. One brake duct fan per corner may be added.
4. The hand brake may be removed.
5. Brake lines shall be steel or metal braided hose. They may be relocated and may be given additional
protection.
6. Brake calipers and/or drums are unrestricted except as limited by this Appendix the GTCS for a specific
make/ model. Brake rotors shall be ferrous material but are otherwise unrestricted. Brake rotors/drums
shall be located in the original position (e.g., inboard vs. outboard).
7. Water cooled brakes are permitted, maximum reservoir capacity two (2) gallons, maximum line size 3/16
inch I.D. The water shall be atomized by an atomizing nozzle, and the water shall enter the air duct a
minimum of twelve (12) inches from the centerline of the spindle/axle.
k. GTLite Rules Concerning Alternate Weights and SIRs
1. Allow currently restricted 2V engines less than 1400ccs to run unrestricted at a 100 lb. weight penalty.
Allow currently restricted 3V and 4V engines less than 1400ccs to run 1mm larger SIR as an option at a 100
lb. weight penalty.
2. Allow all 2V and 3V restricted engines less than 1600ccs to run 1mm larger SIR as an option at a 125 lb
weight penalty.
3. Allow all 4V restricted engines less than 1600ccs to run 1mm larger SIR as an option at a 175 lb weight
penalty.
4. Competitors running the alternate SIR must display “+1mm” on the side of their car next to their new
weight.
5. Competitors running the unrestricted option must display “UNR” on the side of their car next to their new
weight.
6. Compression ratio limited to 15:1 for SIR restricted engines.
l. GT2 Rules Concerning Alternate Weights and SIRs
1. Traditional GT2 cars that are currently required to run an SIR may run unrestricted induction with a 350
lb. weight penalty. This weight penalty is to be added prior to any “add-on” penalties, such as sequential
shifting, IRS, etc.
m. GT3 Rules Concerning Alternate Weights and SIRs.
1. Traditional GT3 cars that that are currently required to run an SIR may run +1mm above spec line listed size
size with a 175lb. weight penalty.
2. Competitors running the alternate SIR must display “+1.mm” on the side of their car next to the new
weight
FP-GTL Cars
Note; FP/GTL Cars must comply with rules as stated in Appendix N of the GCR. GTL cars are allowed to compete under the 9.1.2.F. GT-2, 3, LITE Category Specifications at the Regional Level.
Acura
Model Years Body Style Drive-line Wheel-base (in) Notes
Integra (-93) 2dr FWD 96.5 May use any class legal Honda engine.
Integra (94-) 2dr FWD 101.2 May use any class legal Honda engine.
RSX (02-05) 2dr FWD 96.5 / 101.2 May use any class legal Honda engine.
FP-GTL Cars - ALFA ROMEO
Model Years Body Style Drive-line Wheel-base (in) Notes
GT-1300 Junior NA 2dr RWD 92.5
GTA Junior NA 2dr RWD 92.5
Alfetta GT NA 2dr RWD 94.5
Guilia 1300 NA 2dr RWD 98.8
Guilia 1300 TI NA 2dr RWD 98.8
GTV 1600 NA 2dr RWD 92.5
GTV 1750 / 2000 NA 2dr RWD 92.5
Giulietta Spider / Giulia Spider NA 2dr RWD 86.6 / 88.6
All Spider Models (-94) 2dr RWD 88.6
Engines - ALFA
Engine Family Engine
Type
Bore x Stroke
(mm)
Disp.
(cc)
Head Type Valves/
Cyl.
Fuel Induction Weight
(lbs)
Notes
DOHC 78.0 x 67.5 1130 Alum, Crossflow 2 Unrestricted 1565
DOHC 74.0 x 75.0 1290 Alum, Crossflow 2 Unrestricted 1565
DOHC 80.0 x 67.5 1357 Alum, Crossflow 2 Unrestricted 1565
DOHC 78.0 x 82.0 1570 Alum, Crossflow 2 24.5mm SIR 1935
DOHC 80.0 x 75.0 1508 Alum, Crossflow 2 24.5mm SIR 1905
DOHC 80.0 x 88.5 1779 Alum, Crossflow 2 24mm SIR 2040 Alt. head: 19510-01053-04 (twin plug).
FP-GTL Cars - AMC
Model Years Body Style Drive-line Wheel-base (in) Notes
AMC/Renault Alliance NA 3dr FWD 93.5
AMC/Renault Encore NA 2dr FWD 93.5
Engines - AMC/Renault
Engine Family Engine
Type
Bore x Stroke
(mm)
Disp. (cc) Head Type Valves/
Cyl.
Fuel Induction Weight
(lbs)
Notes
OHV 73.0 x 77.0 1289 Alum, Crossflow 2 Unrestricted 1619 Alternate crossflow head #7700597627.
OHV 76.0 x 77.0 1397 Alum, Crossflow 2 24.5mm SIR 1850 Alternate crossflow head #7700597627.
FP-GTL Cars - BMC thru Rover Group
Model Years Body Style Drive-line Wheel-base (in) Notes
Austin-Healey Sprite NA 2dr RWD 80.0 Roll cage meeting requirements for cars under 1500lbs are acceptable for cars
registered prior to 4/1/82.
MGB & MGB-GT NA 2dr RWD 91.0
MG Midget NA 2dr RWD 80.0 Roll cage meeting requirements for cars under 1500lbs are acceptable for cars registered prior to 4/1/82.
Mini Cooper NA 2dr FWD 80.2 1) Roll cage meeting requirements for cars under 1500lbs are acceptable for cars registered prior to 1/1/82.
2) Reduce by 100 lbs with original suspension and 10” wheels.
3) Front and rear body seams may be removed.
4) Full flat bottom floors are permitted.
5) Rear valance panel may be removed or modified.
6) Rain gutters may be modified.
Austin America NA 2dr FWD 93.5
BMW Mini 2002-
2013
2dr FWD 97.1
Triumph Spitfire NA 2dr RWD 83.0 Roll cage meeting requirements for cars under 1500 lbs. are acceptable for cars registered prior to 4/1/82.
Engines - BMC thru Rover Group
Engine Family Engine
Type
Bore x Stroke
(mm)
Disp. (cc) Head Type Valves/
Cyl.
Fuel Induction Weight (lbs) Notes
MG “B” Series OHV 80.3 x 88.9 1798 Iron, non-
Crossflow
2 24.5mm SIR 2035
Triumph Spitfire OHV 69.34 x 76.2 1147 Iron, non-
Crossflow
2 Unrestricted 1492
Mini/Sprite/Midget OHV 2.78 x 3.20