Updated

Daytona Beach, FL (SportsNetwork.com) - NASCAR handed down severe penalties to Denny Hamlin's No. 11 team in the Sprint Cup Series on Tuesday after his Joe Gibbs Racing car failed post-race inspection this past Sunday at Indianapolis Motor Speedway.

Hamlin's crew chief, Darian Grubb, and car chief, Wesley Sherrill, have both been suspended for the next six Sprint Cup races. The two JGR members will also be on probation for the next six months. Grubb has been fined $75,000 plus an additional $50,000 post-race fine for a total of $125,000.

Furthermore, Hamlin received a loss of 75 points in the driver's championship standings, and J.D. Gibbs was docked 75 points in car owner points.

Following his third-place finish in the Brickyard 400 at Indianapolis, NASCAR officials found issues with the rear firewall block-off plates on Hamlin's No. 11 Toyota. Those parts in question were confiscated and taken to NASCAR's Research and Development Center in Concord, North Carolina for further evaluation.

NASCAR determined the parts were illegal and said in a news release the rules infraction by the No. 11 team at Indianapolis was a P5 level penalty.

Prior to the start of this season, the sanctioning body instituted a new penalty structure, referring to it as a "deterrence system." Penalties are now on a scale, beginning with warnings and then including six penalty levels. P1 is the least significant, and P6 is the most significant.

The P5 level penalty, as outlined in Section 12-4.5 A (9) of the 2014 NASCAR rule book, states, "Approved parts that fail or are improperly installed to fail in their intended use of great importance (e.g.; rear wheel well panels that fail and allow air evacuation in the trunk area; oil box cover that fails and allows air evacuation in the driver compartment; shifter boot cover that fails and allows air evacuation through the floor pan)."

Joe Gibbs Racing said in a statement it will appeal the penalties. The team also noted Grubb and Sherrill will begin serving their suspensions with this weekend's event at Pocono Raceway. There are six races remaining before the Chase for the Sprint Cup championship begins on Sept. 14 at Chicagoland Speedway.

Hamlin's loss of 75 points dropped him from 11th to 21st in the rankings. He won the May 4 race at Talladega Superspeedway, which virtually guaranteed him a spot in the Chase. Hamlin is now 213 points ahead of the 31st-place driver (David Gilliland).

In its penalty announcement, NASCAR noted Hamlin's team violated the following sections of the rulebook:

- 12.1 - Actions detrimental to stock car racing.

- 20-2.1 - Car body must be acceptable to NASCAR officials and meet the following requirements:

(K) - Any device or ductwork that permits air to pass from one area of the interior of the car to another, or to the outside of the car, will not be permitted. This includes, but is not limited to, the inside of the car to the trunk area, or the floors, firewalls, crush panels and wheel wells passing air into or out of the car.

(L) - All seams of the interior sheet metal and all interior sheet metal to exterior sheet metal contact point must be sealed and caulked. This includes, but is not limited to, floors, firewalls, wheel wells, package trays, crush panels and any removable covers.

- 20-3.4 - All references to the inspection surface in sub-section 20-3.4 have been determined with the front lower edge of both main frame rails set at six inches and the rear lower edge of both main frame rails set at eight inches. For driver protection, all firewalls, floors, tunnels, and access panels must be installed and completely secured in place when the car is in competition.

- 20-3.4.5 - A rear firewall, including any removable panels or access doors, constructed using magnetic sheet steel a minimum of 22 gage (0.031 inch thick), must be located between the trunk area and the driver's compartment and must be welded in place. Block-off plates/covers used in rear firewalls in place of blowers, oil coolers, etc., must be constructed of 22 gage (0.031 inch thick) magnetic sheet steel. Block-off plates/covers must be installed with positive fasteners and sealed to prevent air leakage. Carbon fiber or aluminum block-off plates/covers will not be permitted.