Limited Drag Radial

Limited Drag Radial is the newest radial class in the fold, beginning in January 2016, that has brought stock appearing cars packing big time horsepower together into one class with a strict rules set and limited power adders. Many of the cars seen in LDR resemble the stock appearing counterparts that they began life as. The majority of the field is running in the 4.20 and 4.30 elapsed time range. LDR is quickly growing with the fan base and the racers as one of the most competitive and closely contested classes in racing today with the three major power adders all within just a few hundredths of a second. In now it’s second season, the class creators are running a season championship with some of LDR’s largest and best venues/events piled into a championship hunt with $5,000 up for the winner and the Mustang Mike Memorial Championship Trophy! OSCR kicked off the points program in 2017 and we look forward to being a part of it again in 2018 with the fifth running of the rapidly growing category that looks to be one of the next big things in drag radial racing very soon. Listed below is our payout for the 2018 edition along with the class rules.

One of the things that has rapidly drawn fans to LDR is the diversity of the body styles. Take for instance, Jason Digby’s single turbocharged, all Mopar, leaf spring packing Dodge Dart that is piloted by Lyle Barnett.

Event Payout
Presented by: Hyperaktive Performance Solutions, TRZ Motorsports and Wiseco Automotive

$5,000 to Win
$1,500 to Runner-Up
$500 to Semi-Finalists
$300 to Quarter-Finalists
$150 to Eighth-Finalists

$150 Entry Fee (Car & Driver)
Fully Guaranteed Purse

2018 Class Rules, Last Modified on November 27, 2017

The class designation is LDR. All entrants must display this designation on all four corners of their car with their car number.

This is an 1/8th mile, heads up category running on a .400 Pro tree with a professional pairing ladder. This is a single power adder class only!

LDR will feature a championship points series in 2018 with a schedule of 8 events that will be located on the website for review and selection. At the end of the season, we will select 6 events to tally your points from, if you attend all the events, you will receive a points bonus for season-long support. Entry into the points series is FREE for any person who buys a tech card into any LDR event. We ask that you fill our Championship Chase Form found at to make our job easier and to ensure no overlapping car numbers making your time at the track easier and smoother. Points will be accumulated from the time you pass the technical inspection process, to qualifying, to the final round of eliminations. Entries will receive 20 points for passing tech, the top five qualifiers will receive bonus points, 10 points per round win (including final round victory), 2 points for an event win and 1 point for an event runner-up. 2018 Points Fund will be posted soon with a complete breakdown, also to be found on the class website.

All NHRA and Local Track Safety rules apply for car and driver, including the use of an oil retention device and/or engine diaper is MANDATORY. Any competitor causing an oil down that does not have an oil retention device will lose 5 points off their 2018 LDR Championship Points tally.

The car must retain its original appearance, profiles and dimensions. No aftermarket one-piece bodies. OEM door jamb and quarter panels must be used. No modified front ends to achieve maximum NHRA overhang, must stay within original body dimensions. Must retain factory body lines with removable composite components as in hood, front bumper, front fenders, doors and deck lid. Any beam tripping devices forward of the bumper are prohibited. Aftermarket front bumpers (snowplows or valances) cannot have more than 2 inches of overhang over the stock bumper dimensions, failure to abide by this rule will result in disqualification. Aftermarket wings and spoilers are permitted. A hood must be used; scoop or hood must cover entire induction system. Exceptions are throttle bodies or carburetors on naturally aspirated and nitrous oxide assisted engines along with intake manifolds/throttle bodies on boosted engines. Those may protrude through the hood for clearance, if needed. Forward facing hood scoops/turbocharger/supercharger inlets are permitted. OEM/Lexan windows are permitted. Front ends must be within the spirit of the rules and legality is at the discretion of the race director. Firewall must be in the stock location; stock firewall can be modified.

Door cars only, no pro mod or full tube chassis. Backhalf style cars are permitted. No wheelie bars. Any rear suspension is permitted. Factory front frame rails are mandatory, they can be modified and must extend to the center of the front spindle. Aftermarket front K-Members are permitted, must bolt in the factory location. Factory equipped ‘bolt-in’ subframe cars are permitted an aftermarket bolt-on front end (Smith Racecraft) for ’62-’74 Nova and ’67-’81 Camaro/Firebird, must bolt in. Factory wheelbase for year/make/model must be maintained, (+/- 1 inch). A minimum height of 3 inches from the front of the vehicle to 12 inches behind front spindle center line is mandatory. A minimum height of 2 inches for the rest of the vehicle is mandatory (except for oil retention device and/or headers).

No cubic inch limit for any naturally aspirated or power adder combination. All engines must have a diaper, belly pan or oil retention device. Nitrous oxide is permitted to run any type multi-stage nitrous system with no restrictions. Nitrous entries must have bottle securely contained in a bottle bracket. Maximum bore spacing for all boosted combinations is 5.000 or less. Turbocharger combinations are limited to a single turbocharger at an 118mm maximum, small block and big block. Billet engine block and billet cylinder heads combination will carry extra weight addition, addressed below in the weight additions/reductions section. Maximum size on all twin turbocharged combinations is 88mm, anything over that dimension will be deemed illegal. Turbochargers will be verified by measuring the housing bore at the leading edge of the impeller wheel and must retain the contour of the compressor housing, stepped or clipped compressor wheels are prohibited. Inserts or reducers to achieve inlet or outlet dimensions are prohibited. Supercharger combinations are limited to a single centrifugal supercharger at a F3-139 maximum, small block and big block. Maximum size on all twin centrifugal supercharged combinations is the base F1X, the F1X-12 is prohibited. Roots superchargers are restricted to a 14-71 maximum. Screw superchargers are prohibited. Dual power adders are strictly prohibited.

All entries must be self-starting from inside the vehicle. A master cut-off switch is mandatory on the rear of the car with an on/off sticker. Any electronic ignition system is allowed, see below for weight additions/reductions. Computer/Data Recorders are permitted.

Mufflers or inserts are required on all cars except for turbo cars. Exhaust may exit underneath car or out the front fenders/valance but must not affect timing or staging beams.

Matt Bell from Red Line Motorsports overcame a tough four sessions of qualifying to power through five rounds of eliminations and emerge victorious in 2017, hoisting the $5,000 winner’s check at the end of the weekend!

The first TWO feet (minimum) of the line coming from the CO2 bottle must be 1/4″ plastic line with push-locks. No braided steel lines direct from the CO2 bottle to ensure no nitrous oxide is being used. Braided steel line may be used after the first two feet of plastic/push-lock line to protect the line running through the firewall and/or around exhaust system.

Any intercooler is permitted on gasoline combinations only. Must be securely mounted to chassis or mounts with preferred hardware. Water box must be contained in a safe environment with a top to enclose water/ice during the run. Intercooler combined with a methanol fueled combination is prohibited.

Any transmission permitted. Any converter permitted. Lock-Up Transmission/Converter setups are permitted on naturally aspirated and nitrous oxide combinations only, prohibited on turbocharger or supercharger combinations.

Any gasoline, E85 or M1 permitted. M5 is prohibited. No nitromethane or additives.

Any brand 275/60/15 drag radial. Mickey Thompson 295/65/15 Drag Radial (PN: 3558) and Hoosier 295/65/15 DR2 (PN: 17316DR2) will be the legal tire options for the ‘big’ tire option. Nitrous oxide combinations can run any tire at base weight, no weight penalty on nitrous cars for the big tire. Any 481X/HEMI or any hemispherical headed combination equipped with single turbocharger, twin turbochargers or centrifugal supercharger(s) must be on a 275/60/15 drag radial, no big tire option for that engine/power adder combination. Must stay on the same tire throughout the entire event. This officially makes Limited Drag Radial a DOT tire class in 2018.

All weights are minimum with driver in car.

– Small Block – No Minimum
– Big Block – No Minimum

– Small Block – 2,200 lbs.
– Big Block (4.840 Bore, Any Transmission) – 2,550 lbs.
– Big Block (5.000 Bore, Any Transmission) – 2,700 lbs.
– Big Block (5.000+ Bore, No Lock-Up Transmission) – 2,850 lbs.
– Big Block (5.000+ Bore, Lock-Up Transmission) – 2,900 lbs.

– Small Block, Single Turbo – 2,850 lbs.
– Small Block, Twin Turbo – 3,000 lbs.
– Big Block, Single Turbo – 3,100 lbs.
– Big Block, Twin Turbo – 3,225 lbs.

– Small Block, Roots – 2,750 lbs.
– Big Block, Roots – 2,900 lbs.
– Small Block, Single Centrifugal (ProCharger F1 or Equivalent) – 2,800 lbs.
– Small Block, Single Centrifugal (ProCharger F2 or Equivalent) – 2,825 lbs.
– Small Block, Single Centrifugal (ProCharger F3 or Equivalent) – 2,850 lbs.
– Small Block, Twin Centrifugal – 3,000 lbs.
– Big Block, Single Centrifugal (ProCharger F1 or Equivalent) – 3,050 lbs.
– Big Block, Single Centrifugal (ProCharger F2 or Equivalent) – 3,100 lbs.
– Big Block, Single Centrifugal (ProCharger F3 or Equivalent) – 3,150 lbs.
– Big Block, Twin Centrifugal – 3,250 lbs.

– 100 lb. Weight Addition for the 295/65/15 ‘Big’ Tire Option, (MT 3558 or Hoosier 17316DR2)
– 100 lb. Weight Addition for 481X/HEMI or Hemispherical Headed BBC/BBF.
– 50 lb. Weight Addition for Any ALL Billet Boosted (Turbo or Supercharger) Combination (Heads and Block), other than HEMI or 481X.
– 25 lb. Weight Reduction for Conventional Headed BBC Combinations on Gasoline.
– 50 lb. Weight Reduction for Centrifugal Supercharger Combinations on Gasoline.
– 50 lb. Weight Reduction for Leaf Spring Rear Suspension.
– 481X, HEMI and Any Hemispherical Headed Engine must be on 275 Drag Radials if power adder is single turbocharger, twin turbocharger or any centrifugal supercharger combination.

*** Rules are subject to review at any time. We are going to do our best to keep the racing as tight and competitive for all combinations throughout the entire 2018 season. ***

Rules from

Photo Credit: James Sisk Photography
Video Credit: TheRacingVids