▁for ▁their ▁other ▁on - board ▁race ▁tim ers ▁such ▁as : ▁thro tt le ▁stop ▁tim ers , ▁data ▁log gers ▁( data ▁record ers ), ▁sh if ter ▁tim ers , ▁R PM ▁switch es , ▁electronic ▁nit r ous ▁ox ide ▁injection ▁controllers ▁and ▁other ▁devices . ▁Del ay ▁box ▁manufact ur ers ▁that ▁do ▁not ▁receive ▁N H RA ▁appro val ▁are ▁shut ▁out ▁of ▁the ▁entire ▁drag ▁race ▁electron ics ▁market . ▁ ▁As ▁mentioned ▁above , ▁in ▁the ▁paragraph ▁one ▁under ▁" Cont ro vers ial ▁Use ", ▁many ▁drag ▁race ▁track ▁operators ▁began ▁div iding ▁race ▁day ▁into ▁" box " ▁and ▁" no ▁box " ▁classes , ▁with ▁" no ▁box ▁class " ▁being ▁prohib ited ▁from ▁using ▁any ▁type ▁of ▁delay ▁box ▁in ▁their ▁race ▁cars . ▁However , ▁electronic ▁track ▁timing ▁systems ▁were ▁still ▁used ▁for ▁the ▁" no ▁box ▁class " ▁meaning ▁that ▁a ▁rac er ▁willing ▁to ▁che at ▁could ▁rather ▁easily ▁conce al ▁a ▁delay ▁box ▁somewhere ▁in ▁his ▁car ▁( or ▁on ▁his ▁person ), ▁and ▁have ▁an ▁unf air ▁advantage ▁over ▁his ▁compet itors . ▁Race ▁track ▁operators ▁therefore ▁created ▁a ▁monument al ▁task ▁for ▁themselves ▁in ▁enfor cing ▁rules ▁against ▁electronic ▁devices ▁in ▁Bra cket ▁R ac ings ▁" no ▁box ▁class ", ▁and ▁as ▁such , ▁rarely ▁purs ue ▁enfor cement . ▁On ▁the ▁occasions ▁a ▁track ▁operator ▁does ▁attempt ▁to ▁catch ▁che aters ▁with ▁delay ▁tim ers ▁in ▁the ▁" no ▁box " ▁class ,