The Ford Mustang has a long history of road racing all over the world. The Mustang has been a tremendously competitive V8 race car in SCCA A and B Production, TRANS-AM, IMSA GTO, SCCA Super Touring Over (STO), NASA American Iron (AI and AIX), Grand Am Continental Sports Car Series, SCCA World Challenge, FIA GT, and American Le Mans GT competition. This article discusses how to build a NASA American Iron (AI) or SCCA Super Touring Over (STO) class road racing Mustang starting with a 1994 through 2013 vehicle.
STEP 1: Decide What Year Mustang Race Car You’re Going to Build
The first thing you should think about when building your V8 Mustang race car is what model year to start with. Although NASA’s American Iron allows cars as old as the 1960′s and SCCA’s Super Touring Over allows cars back to 1995, it’s much better to start with a modern car that has a stiff and light unit body and many parts available at a reasonable price. Each model will need work on weight reduction, suspension, motor, transmission, etc. to be competitive.
Fourth Generation Mustangs (SN-95):
- 1994-1995 Mustang GT with 5.0L (302 cid) Windsor V8 pushrod motor
- 1994-1995 Mustang Cobra with 5.0L (302 cid) Windsor V8 pushrod motor and Ford Racing GT-40 manifold (240 hp)
- 1995 Mustang Cobra R with SVT 5.8L (351 cid) Windsor V8 pushrod motor (300 hp) and Tremec 3550 5-speed manual
- 1996-1998 Mustang with aluminum 4.6L V8 SOHC Modular motor (215 hp, 1998 has 225 hp)
- 1996-1998 Mustang Cobra with aluminum 4.6L V8 SOHC Modular motor (305 hp) with T-45 5-speed manual
- 1999 Mustang Cobra (320 hp) with Teksid engine block and independent rear suspension
- 1999-2004 Mustang GT with 4.6L V8 SOHC Modular motor and new heads (260 hp)
- 2001 Mustang Cobra (320 hp) with WAP engine block and independent rear suspension
- 2001 Mustang Bullitt
- 2003-2004 Mustang Mach 1
- 2003-2004 Mustang Cobra (390 hp)
Fifth Generation Mustangs (S-197):
- 2005-2009 Mustang GT with 4.6L aluminum block SOHC 3-valve Modular V8 motor with variable timing cam (300 hp) and Tremec TR-3650 5-speed manual
- 2010 Mustang GT with 4.6L aluminum block SOHC 3-valve Modular V8 motor with variable timing cam (315 hp) and Tremec TR-3650 5-speed manual
- 2011-2013 Mustang GT with 5.0L Coyote 4-valve V8 (435 hp) and Getrag-Ford MT82 6-speed manual
- 2011-2012 Mustang Shelby GT500 with 5.4L supercharged aluminum block 4-valve V8 (550 hp) and Getrag-Ford MT82 6-speed manual
- 2011-2013 Mustang Boss 302 with 5.0L Coyote 4-valve V8 (444 hp) and Getrag-Ford MT82 6-speed manual
- 2011-2013 Mustang Boss 302S (Ford Racing factory built at Watson Engineering in Taylor, MI) with 5.0L Coyote 4-valve V8 (444 hp) and Getrag-Ford MT82 6-speed manual
- 2012-2013 Mustang Boss 302 ”Laguna Seca Edition”
- 2013 Mustang Shelby GT500 with 5.8L supercharged aluminum block 4-valve V8 (662 hp) and Getrag-Ford MT82 6-speed manual
NASA and SCCA Rules for the Ford Mustang
For a Mustang race car to be eligible for American Iron or Super Touring Over classes, it must have: 1) a unit body construction (no tube frame), 2) minimum 100 inch wheelbase, 3) front engine/RWD layout, 4) a solid axle or “approved” independent rear suspension, 5) stock bodywork including front clip, floorpan, and subframes. Limited production factory approved Mustangs such as the SVT Cobra R, FR500, Shelby, Roush, Saleen and Hennessey are acceptable, but these tend to be very expensive cars to start with.
A piece of advice here: It always costs twice as much to build a car from scratch as it does to start with an existing race car that has the major work such as cage and suspension upgrades already installed. It’s much easier and less costly to incrementally improve and existing Mustang American Iron or STO race car than it is to build one from scratch from a street car.
When deciding on a car and motor package, it’s critical to conform to NASA’s rules for power-to-weight and torque-to-weight ratios. The minimum weight for a V8 powered AI car is 2700 pounds with driver. The “American Iron” (AI) class has a strict 9.5:1 (9.5 pounds of vehicle weight per each horsepower) power to weight ratio maximum and 9:1 (9 pounds of vehicle weight per each foot-pound) torque to weight ratio maximum as measured at the rear wheels. The SCCA Super Touring Over (STO) rules have similar limitations. These classes are about fair competition and reasonable cost as opposed to maximum horsepower.
See NASA’s American Iron rules here: http://www.nasaproracing.com/rules/american_iron_rules.pdf
See SCCA’s Super Touring Over rules Section 9.1.4 here: http://www.calclub.com/html/html2/archives/2012/2012-GCR.pdf
If you want to go beyond these limited rules you can race in NASA’s American Iron Extreme (AIX) or SCCA’s Super Producton Over (SPO) which are basically unlimited classes.
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