Today’s Grassroots Drag Racing Market - Engine Builder Magazine

Today’s Grassroots Drag Racing Market

Bracket racing is the most popular form of drag racing. Participants in various bracket racing classes make up the majority of NHRA & IHRA land racers in the U.S.

Drag races usually cover 1/8 or 1/4 mile tracks on land, a couple hundred feet for mud and usually 1/4 mile for water. Some high-powered land drag classes limit distances to 1,000 feet to keep speeds down. As a result in all of these, duty cycle under full power is low compared to sprint car, road racing or top speed events where engines are under full load for a longer time interval. Engine cooling systems are less critical and fuel mixtures are leaner.

While motorcycle and snowmobile drag racing is expanding, a full-bodied car is quite common for land vehicle racing. Some are dragsters, altered or fiberglass or carbon fiber replicas.

Typical engine building specs:

• Usually small or big block V8 with single 4 barrel is a niche market; 4 cylinder VW niche; occasional other engine combos with various cylinder numbers;

• Some bracket racers use mechanical fuel injection; some use EFI;

• Some use nitrous oxide assist; power adder from 75 to 900 HP on nitrous;

• Nitrous oxide at the higher power levels can get hard to manage; the nitrous oxide bottle temperature is critical.

In land racing, there is usually an automatic transmission with a torque converter requiring a broad power band and good off-idle response. Torque converters with over 5,000 RPM stall speed are quite common. Therefore you can cam the motor for a torque peak at 5,000 to 5,500 RPM. That would be 255 to 270 deg. duration camshaft.


Usually around 7,000 RPM peak


Engine power “on the motor”


High volume, low priced small block usually 500 to 700 HP


High volume, low priced big block 600 to 900 HP


High end, big power small blocks can go to 900 HP


High end, big power big blocks can go to 1500 HP on single carburetor.

Mechanical fuel injection and electronic fuel injection (EFI) are both popular in grassroots racing.

For mud racing, truck or special chassis are common. For boat racing, flat bottom, tunnel and jet vee-bottom styles are common. In many heavier boats, such as heavy day cruisers with big engines, a transmission is used in some setups. Thermostat controlled engine temperature is helpful in boats to get engines up to temperature for more racing power.

Fuels Used

Racing gas is common throughout grassroots racing, however there are other options.

E85 is becoming more popular as a racing fuel. For racing with E85, a fuel check is recommended to establish control over the ethanol-to-gas ratio. E85 at the pump is reported to vary from E70 to E90. Different fuel amounts are needed for that range of fuel mixtures. Mechanical fuel injection and carburetor intakes do not compensate for mixture ratio changes. Adjustment to jetting is necessary for different mixture ratios.

EFI with “open loop control” does not compensate for mixture ratio changes either. Reprogramming the air to fuel ratio map for different mixtures is necessary.

EFI with “closed loop control” can compensate for different mixture ratios automatically. The fuel volume is changed to match an air-to-fuel ratio target in the computerized fuel map.

However, air-to-fuel ratio baselines change for different ethanol-to-gasoline mixture ratios.

Mixtures with more ethanol need a fuel map with lower numeric air-to-fuel ratios. Mixtures with more gasoline need a fuel map with higher numeric air-to-fuel ratios. Modifying an AFR fuel map is helpful for dealing with different ethanol mixture ratios. An engine builder with this experience has a distinct advantage over a backyard engine builder who may be doing this for the first time.

Bracket drag racing engines are expected to last a season if good parts are used. Some classes use throttle-limiting devices to lower power. Some faster classes use blown alcohol. For the most part, nitromethane is not allowed in bracket racing although low percentages of nitromethane are occasionally used. An experienced engine builder with knowledge of the air-to-fuel ratio needs for lower percentages has an advantage.

Traditional grassroots drag racing class examples

One of the advanced grassroots drag racing categories is Stock Eliminator for OEM type vehicles. One of these classes is NHRA Stock Eliminator. Typical engine specs are:

• Engine modifications limits, run on gas, in OEM stock based full body car

• Most of the engine specs are required to be original equipment except the following:

• Any camshaft duration

• Distributor change

• Headers; usually stepped pipe diameters with a 4-into-1 collector design

• Hone block with 180 deg. F hot water circulating through it during the hone, with cylinder head honing plates torqued to the block; both to strain block in the close-to-usage condition for a precise honing job

• Reduced oil pressure combined with premium synthetic lubricants

• Accurate blue printing of block and heads to OEM based specs

• Cylinder head multi angle valve seats with OEM based head specs.

OEM-style cylinder heads have “spec” port volume and chamber volume. This is without visible alteration to ports or combustion chambers. However, some engine builders are known to relocate ports in cylinder head castings with cutting and welding; then bead blast welds to hide the change.

These are often $5K+ cylinder heads, and frequently in cast iron. We had experience with cast iron or Stellite filler rod for welding. Pre-heating to a glow, over 1,700 deg, F was helpful. Premium Stock Eliminator cylinder head preparation such as this is definitely out of the realm of backyard engine building and well into the realm of an experienced engine builder. The labor cost alone for these engine builds can be several thousand dollars.

This engine class has an OEM-style carburetor, however fuel delivery circuit upgrades are common to increase the volume of fuel. Truing the carburetor venturies is done to increase airflow, however, stock appearance to airflow is a class requirement. These changes are also out of the realm of backyard engine building and definitely a specialty.

Example: an OEM small block factory rated at 250 horsepower can pull over 400 horsepower with the careful long block changes, cam duration changes, carburetor blueprinting, and step headers with most other parts in OEM specification

Example: an OEM big block factory rated at 425 horsepower can be pull close to 600 horsepower with the legal modifications and a careful build.

Another real serious grass roots drag racing class is the NHRA Super Stock example:


Mostly OEM style components, such as previously described in the Stock Eliminator category, but with the following changes:


Any roller cam setup


Ported heads


Any intake manifold that fits under the stock hood.

Example: an OEM 335 HP 428 ford record holder dynos over 800 horsepower at over 8,000 RPM

Example: an OEM 275 HP 350 GM combination dynos over 600 horsepower at over 8,000 RPM.

Racers with vintage Super Stockers from the ‘60s may compete in drag races with period correct 352, 390, or 427 cubic inch FE engines. Different carburetor setups are legal: 2 barrel, 4 barrel, three 2-barrels, or two 4-barrel OEM carburetor setups. Ford FE engine builds are interesting because OEM cylinder head & piston combinations can be put together to generate compression ratios from 8 to 1 to over 14 to 1. Higher compression combinations are attainable by mixing low and high altitude OEM components, often legal in various Stock Eliminator classes.

Still another popular grassroots racing class is NHRA Competition Eliminator. The following are examples of specs:


Normally (naturally) aspirated engines in special purpose racecars with different rules and indexes for various body/chassis combinations from full body to dragster


A few forced induction classes for roots blowers or turbochargers


Most classes use ‘spec’ gasoline


Some classes use methanol


Most any engine modifications limited to original valve count and approximate valve location


No nitrous oxide.

Nostalgia Drag Racing

Another grassroots racing category is Nostalgia racing that is based on older drag racing engines and racecar platforms. Various classes from bracket racing to max effort blown nitromethane have their own restrictive rules. A lot of engine combinations change between many of the competitors.

IHRA Classes

IHRA is heaven for the engine builder who services the grassroots drag racer. Various bracket and competition eliminator categories are run at regional and national events all over North America and Canada. Categories range from stock body, stock engine to all-out dragsters with blowers and nitro fuel.

IHRA drag racing is dominant in the central and eastern USA and Canada. Numerous bracket classes for different power levels attract a thousand participants at an event. Engine build combinations range from OEM stock block on up to highly modified combinations.

Faster IHRA class are run for racecars & trucks including purpose-built replicas of a GM S-10 with a tubular frame and very high powered V8 engine build.

Several IHRA dragster classes attract engine builds again from stock block baselines with special EFI all the way up to supercharged setups and setups with nitrous oxide running over 200 MPH in the quarter mile. ν

You May Also Like

Shop Solutions – January 2024

Before installing cam bearings, make sure to chamfer any oil holes and clean up back grooves of any sharp edges.

Engine Builder and Engine Pro present Shop Solutions in each issue of Engine Builder Magazine and at enginebuildermag.com to provide machine shop owners and engine technicians the opportunity to share their knowledge to benefit the entire industry and their own shops. Those who submit Shop Solutions that are published are awarded a prepaid $100 Visa gift card. Submit your Shop Solution at [email protected]. You must include your name, shop name, shop address and shop telephone number. Submitted Shop Solutions not published will be kept on file and reevaluated for each month’s new entries.

The Road to AAPEX Season 2, Ep 8

The innovation of the Lincoln Highway wasn’t just about building roads—it was about putting them on the map. The Wyoming Historical Society notes that the abandoned routes laid down by the Union Pacific railroad from 1867 to 1869 were often the best, and sometimes the only, east-west path available when developing the Lincoln Highway. In fact,

The Road to AAPEX Season 2, Ep 7

Rolling through Nebraska, Babcox Media’s Joe Keene meets kindred spirits as he drives the rare Lincoln Blackwood he refurbished for his journey to AAPEX. Along the way, he meets a family traveling the Lincoln Highway section by section, taking in sights such as the Great Platte River Road Archway Monument and the Classic Car Collection,

The Road to AAPEX Season 2, Ep 6

It’s the unexpected moments that make a trip memorable. Babcox Media’s Joe Keene, an ASE-certified technician who fixed a rare Lincoln Blackwood, enters Iowa on his drive to AAPEX and discovers the charm of small-town America along the Lincoln Highway. A standout spot is the Lincoln Highway Hotel. Related Articles – The Road to AAPEX

The Road to AAPEX Season 2, Ep 5

To know where you’re going, you have to know where you’ve been. For Babcox Media’s Joe Keene, an ASE-certified technician charged with fixing up a rare Lincoln Blackwood, it means heading back to Transtar Autobody Technologies in Detroit to put the finishing touches on the Blackwood. Then, he’ll put Babcox Media HQ in the rearview

Other Posts

Kaiju Motorsports’ All-Billet Subaru EJ 2.5L Engine

Hands down, this was one of the more eye-popping engine bays we saw during the 2023 PRI Show. The Kaiju Motorsports-built STi Subaru is a cool car in and of itself, but with an all-billet 2.5L EJ engine featuring titanium piping, this thing stopped you in your tracks and forced your head to turn. We

Scheid Diesel’s Billet Cummins Dragster Engine

One of the coolest diesel dragsters around belongs to Scheid Diesel. Shop owner Dan Scheid and machinist and drag racer Jared Jones work together on the billet Cummins-powered dragster. We caught up with Jared during the 2023 Ultimate Callout Challenge to get the details of what makes their Cummins engine tick in this Diesel of

Scheid Cummins engine
415 cid Billet Cummins Engine in a Pro275 Cadillac

Ring Racing owner Jared Ring revealed a metamorphosis to this 2016 Cadillac ATS-V last week. The Cadillac is now equipped with radial tires and a 415 cid Cummins engine built by Freedom Racing Engines, and the combo just competed at Lights Out 15.

Cummins-powered Cadillac ATS-V Pro275 drag car
Turbocharged Billet K24 Honda Engine

Noonan Race Engineering is well-known for its V8 engine platforms, but the shop has now dipped its toe into the 4-cylinder world with a billet K24 Honda engine. The objective – huge horsepower, while keeping factory creature comforts. Check it out!