N/A10.5
CLASSOVERVIEW
N/A10.5isaheads-upclassdesignedfornaturallyaspiratedsmallblockandbigblockengines.
Smallblockengineshaveamaximumenginesizeof470inches.Bigblockengineshavea
maximumenginesizeof650inches.Withnomajorenginelimitations,N/A10.5isoneofthe
nation’spremiernaturallyaspirateddragracingseriesclassesforenginebuildersandracers
alike.Allentrieshaveaminimumwheelbaseof96inchesandmustcompeteonatrue10.5
racingslick.
Note:Thissetofclassrulesispresentedtoallcompetitorsundertheassumptionthatany
modificationsnotspecificallywrittenwithintheserulesshallbedeemedillegal,unlessthe
competitorhastheexpressedwrittenconsentfromtheNMCATechDirector.
RACINGFORMAT
Thisclasswillbeanallrunheads-upfield,NHRAProStyleLadderona.400ProTree.
SMALLBLOCKBASEWEIGHT(maxcubicinch470)
360=2500+Over360add2.75lbs.percubicinch
380=2555+Over380add2.70lbs.percubicinch
400=2609+Over400add2.65lbs.percubicinch
420=2662+Over420add2.60lbs.percubicinch
440=2714+Over440add2.55lbs.percubicinch
460=2765+Over460add2.50lbs.percubicinch
470=2815
BIGBLOCKBASEWEIGHT(maxcubicinch640)
440=2860+Over440add2.60lbspercubicinch
460=2900+Over460add2.55lbspercubicinch
480=2940+Over480add2.50lbspercubicinch
500=2990+Over500add2.45lbs.percubicinch
520=3039+Over520add2.40lbs.percubicinch
540=3086+Over540add2.35lbs.percubicinch
560=3133+Over560add2.25lbs.percubicinch
580=3178+Over580add2.10lbs.percubicinch
600=3220+Over600add2.00lbs.percubicinch
620=3260+Over600add1.80lbs.percubicinch
640=3296
BigBlockentriesover640cubicincheswillbeassesseda4lbpercubicinchweightpenaltyto
the640cubicinchbaseweight.
Howtofigureyourweight:Weightadditionsfortheabovecategoriesarebasedontakingthe
enginecubicinchandmultiplyitbytheindicatedpercentageandconvertingthatnumberto
pounds.IE:400cubicinch(baseof2609)withacategory2headadds15%=60lbs.anddry
sumpoilingsystemadd5%=20lbsforatotaladdof80lbs.andatotalcarweightof2689
WEIGHTADDITIONS/DEDUCTIONS
Four-linkrearsuspensionmustadd5%ofenginesizeinpounds.
Drysumpoilingsystemsmustadd5%ofenginesizeinpounds.
Spreadboresmallandbigblocksmustadd5%ofenginesizeinpounds.
Billetand/orsheetmetalstyleintakemanifoldsmustadd10%ofenginesizeinpounds.
Secondcarburetororthrottlebodymustadd10%ofenginesizeinpounds.
ManualTransmissionmustadd10%ofenginesizeinpounds.
Pontiac,Buick,Olds,andAMCenginesmaydeduct175lbs.
Moparbigblockwedgeenginesmaydeduct125lbs.
BodyStyleDeductionList:Tier1=25lbs,Tier2=50lbs,andTier3=75lbs.Pleaserefertotable
ofcontentsfortierweightbreakchart.
REQUIREMENTS&SPECIFICATIONS
ENGINE:1
BLOCK
Anyaftermarketcastironorcastaluminumblockispermitted.Billetblocksareprohibited.
HARMONICBALANCER
SFISpec18.1balancerisrequired.
ENGINEMOUNTS&LOCATION
Engine/motorplatesandmid-platesarepermitted.Engineblockandcylinderheadscannotbe
incontactwiththefirewall.
ENGINECOATINGS
Theuseofenginecoatingsispermitted.
CRANKSHAFT
Anyaftermarketcrankshaftsarepermitted.
CONNECTINGRODS
Anyaftermarketconnectingrodsarepermitted.
PISTONS&PINS
Anyaftermarketpistonsandpinsarepermitted.
PISTONSRINGS
Anyaftermarketpistonringsarepermitted.
CAMSHAFTDRIVESYSTEM
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Anycamshaftdrivesystemispermitted.
CAMSHAFT
Anycamshaftispermitted.
LIFTERS/LASHADJUSTERS
Anylifters/lashadjusterspermitted.
CYLINDERHEADS
Anyaftermarketcastironoraluminumcylinderheadsarepermitted.Cylinderheadsmustbe
overheadvalve,twovalvespercylindermaximum,andsinglesparkplugpercylinderdesign.
BILLETHEADSAREPROHIBITED.MoparOEMoraftermarketHemiheadsrunsameasChevyor
Ford.AllProStockstylecylinderheadsnomatterwhatyearproducedareCategory3regardless
ofbrandandarenotavailableforanOEMmanufacturerweightbreak.Pontiac,Buick,Olds,
AMCandMoparcylinderheadsmustmaintainthefactoryOEMportlayoutinordertoreceivea
baseweightdeduction.
SmallBlockEngines:
• Category1heads:runatbaseweight.
• Category2heads:add15%ofenginesizeinpounds.
• Category3heads:add25%ofenginesizeinpounds.
SmallBlockHeads:(seeweightaddsection)
• Category1:Inlinevalveheadsmeasuring1.000orlessbottomofintakeporttodeck.
• Category2:Inlinevalveheadsmeasuring1.001+bottomofintakeporttodeck.
• Category3:Allnon-inlinevalveheads.(cantedandsplayedvalve)
BigBlockEngines:
• Category1heads:runatbaseweight.
• Category2heads:add20%ofenginesizeinpounds.
• Category3heads:add25%ofenginesizeinpounds.
BigBlockFord&ChevyHeads:(seeweightaddsection) • Category1:Headsmeasuring1.000orlessbottomofintakeporttodeck.
• Category2:Headsmeasuring1.001/2.000bottomofintakeporttodeck.
• Category3:Headsmeasuring2.001+bottomofintakeporttodeck.
Note:Allcylinderheadintakeportmeasurementswillbemeasuredafterallworkhasbeen
completedandin‘’race’’form.Theloweringofintakerunnerheighttocircumventtheport
heightweightpenaltiesisprohibited.
INTAKEMANIFOLD
Anyintakemanifoldpermitted.Singlefourcastintakemanifoldsmusthavean‘’asproduced’’
bythemanufacturerexteriorappearance.TheNMCATechDirectorwillhavethefinaldecision
onintakemanifoldappearancevs.weightpenalty.
OILINGSYSTEM
Anyoilingsystem,vacuumpumpandoilpanpermitted.
COOLINGSYSTEM
Anycoolingsystempermitted.
EXHAUSTSYSTEM
Anyexhaustsystempermitted.Allexhaustsystemsmustbedirectedoutofbodyandaway
fromdriverandfueltank.
FUELSYSTEM
Anyelectronic,mechanicalorbeltdrivenfuelpumpsareallowed.Electronicfuelpumpsmust
shutoffwiththemasterelectriccut-offswitch.Fuelcellmusthaveapressurecapandbe
ventedtotheoutsideofthebody.FrontmountedfuelcellsmustmeetSFISpec28.1andbe
mountedbetweentheframerailsorenclosedinaroundtubeframe.Aroundtubeframemust
beconstructedofaminimumof1¼-inchO.D.x.065-inchchromemolytubing.Artificialcooling
orheatingoffuel(i.e.,coolcans,ice,Freon,etc.)prohibited.Circulatingsystemsthatarenot
partofthenormalfuelpumpsystemareprohibited.
EFISYSTEM
Anyaftermarketelectronicormechanicalfuelinjectionmaybeused.Fuelinjectorsizeandor
typeareunlimited.
THROTTLEBODY
Anyaftermarketthrottlebody/bodiespermitted.Maximumoftwothrottlebodiespermitted.
Throttlebodiesthatdonotmounttoaconventional4150/4500flange(adaptersprohibited)
mustrundualcarburetorweightadder.
CARBURETOR
Anyaftermarketcarburetorpermitted.Splitorinlinestylecarburetorsprohibited.Carburetors
thatdonotmounttoaconventional4150/4500flange(adaptersprohibited)mustrundual
carburetorweightadder.
THROTTLELINKAGE
Throttlecontrolmustbeoperatedbythedriver’sfoot.
FUEL
NMCAspecifiedVPRacingFuelsgasolineistheonlyacceptablefuelallowed.TheNMCA
reservestherighttocheckgasolineatanytimeduringcompetition.Failuretopassfuelcheckis
groundsfordisallowanceoftherunduringcompetitionanddisqualificationfromtheevent
duringeliminations.
DRIVETRAIN:2
CLUTCH,FLWHEEL&FLYWHEELSHIELD
FlywheelandclutchmeetingSFISpec1.2,1.3,1.4,or1.5ismandatory.Flywheelshieldmeeting
SFISpec6.2or6.3ismandatory.Clutchmustbemanuallyoperatedbythedriver’sfoot.
Electronics,pneumatics,hydraulics,oranyotherdevicemayinnowayaffecttheclutchsystem.
Thethrow-outbearingmustreleaseallfingers,levers,stages,etc.simultaneously.Stagedor
variablereleaseclutchesareprohibited.
MANUALTRANSMISSION
OEMoraftermarkettransmissionswithamaximumof5forwardspeedspermitted.Clutchless
modelspermitted..Pneumatic,electric,hydraulic,etc.shifterspermitted.
AUTOMATICTRANSMISSION
AnyOEMoraftermarketautomatictransmissionispermitted.Anytorqueconvertoris
permitted.Trans-brakesarepermitted.Pneumatic,electric,hydraulic,etc.shiftersare
permitted.
DRIVELINE
Anysteel,aluminumorcarbonfiberdriveshaftmeetingSFI43.1specispermitted.
REAREND
Anyautomotivetyperear-endispermitted.
BRAKES,STEERING&SUSPENSION:3
BRAKES
Automatedbrakesareprohibited.Theapplicationandreleaseofthebrakesmustbeafunction
ofthedriver.Fourwheelhydraulicdiscbrakesaremandatory.Steelbrakelinesaremandatory.
Brakelinesmustbeoutofflywheelanddrivelineareas.Line-lockispermittedonlyonthefront
wheels.Oneline-locksolenoidwithonebuttonispermitted.Anyotherelectrical,pneumatic,
hydraulic,etc.switchinbrakingsystemisprohibited.Dualmastercylinderismandatoryand
mustbemountedabovethelowerframerails.
STEERING
Anyautomotivetypesteeringsystempermitted.Ifcompetitorisusingacommerciallyavailable
quickdisconnectsteeringwheel,itismandatorythatitmeetSFISpec42.1.
SHOCKS/STRUTS
Coilovershocksarepermittedfrontandrear.Shocksmustbestand-aloneandmaynotbe
adjustableduringrunviaelectronicand/orothermeans.Electronicprogrammableshocks
prohibited.Eachvehiclemustbeequippedwithoneoperatingshockforeachsprungwheel.
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directactionbythedriver
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FRONTSUSPENSION
AftermarketfrontK-membersarepermitted.Aftermarket“bolt-in’’stylecontrolarmfrontend
kitscanbeusedasadirectreplacementforallAmericanproductionvehicleswheretheshockis
attachedtotheuppercontrolarm(fromthefactory)ispermittedwithoutaweightpenalty.(Ex.
’62-‘67ChevyNova&’60-‘65FordFalcon)Modifyingtheshock/struttowerispermitted.
REARSUSPENSION
Stocktype,ladderbarand4-linkstylesuspensionsarepermitted.
WHEELIEBARS
Wheeliebarsarepermittedwithamaximumlengthof80inches.
FRAME:4
CHASSIS
Stock,unalteredframerailsrequiredinfrontsubframefromsuspensionmountingpoints
rearward,framerailsandsubframesforwardofthesuspensionmountingpointsmaybe
modified.Subframesonuni-bodiedcarsmaybejoinedundercar.Aftermarketorcustom
designed(squareorroundtubing)rearframerailspermittedfromtheframekickuppoint,after
marketframerailsforwardofthekickuppointmaybetiedintothestockfloorpan.Mini-tubs
arepermitted.
WHEELBASE
Entriesmustretainstockwheelbasedimensionsof+or–1inch.
GROUNDCLEARANCE
Aminimumof3inchesfromthefrontofthevehicleto12inchesbehindfrontspindle
centerlineismandatory.Aminimumof2inchesfortherestofthevehicleismandatory(except
foroilpanandexhaustheaders).
TIRES&WHEELS:5
TIRES
Maximumreartirepermittedisa30.5inchtallby10.75inchwidebias-plyslick.Tiretreadmay
notextendoutsideofthefender.
WHEELS
Aftermarketracingwheelspermitted.
INTERIOR:6I
UPHOLSTERY
Factoryappearingtypedashismandatory.Carpetingisrequiredfromseatsforward.Factory
doorpanelsordoorpanelsmadeofaluminumorcarbonfiberarerequired.Aftermarket
steeringcolumnispermitted.Aftermarketpedalsarepermitted.
WINDOWNET
WindownetmeetingSFISpec27.1ismandatory.
BODY:7
BODY
AllvehiclesmustmaintainOEMappearancesfortheirspecificyear,make,andmodelbeing
used.AllentriesarerequiredtohavetheOEMbodyshellintactfromthefirewalltothetaillight
panel.Lightweightbodypartsarerestrictedtothefollowing:hood,fenders,bumpers,doors,
andtrunk-lid/deck-lid.Hood,trunk-lid/deck-lid,anddoorsmustbehingedorbeliftoffmodels.
Alterationsoraerodynamicmodificationsareprohibited.
HOODSCOOPS
ForwardfacingandfactoryOEMhoodscoopsarepermitted.
GRILLE
AllentriesarerequiredtohaveanOEMtypegrille.Coveringinfrontoforbehindthegrilleis
permittedandmustmaintaina‘’professionalappearance’’.
FIREWALL
AnonOEMfirewallwillbeallowedprovideditisinthestocklocationandmustbeonepieceof
atleast.024orgreatersteelmaterialfullyattachedinainstocklocation.
FENDERSPLASHPANS
Fendersplashpansmaybealtered.
WINDSHIELD&WINDOWS
AllentriesarepermittedtouseLexanwindows.
FLOOR
Driver’ssidefloorpanmustbesteelandweldedintoplace.Theremainderofthefloorsection
canbe.024inchsteelor.032inchaluminum.Theuseofmagnesiumisprohibited.Transmission
tunnelmayberemovableandmustbemadeofeither.024inchthicksteelor.032inchthick
aluminum.
WHEELWELLS
Allentriesallpermittedtousesteel,aluminum,orcarbonfiberwheeltubs.
WING/SPOILERS
Allentriesarepermittedtouserearwing/spoilers.Wing/spoilersareallowedamaximum
lengthof26inches.Anyadjustmentstothewing/spoilerduringarunareprohibited.
STREETEQUIPMENT
OEMheadlightsandtaillightsforyear/make/modelofvehiclebeingusedmustbeintactand
operational.
APPEARANCE
Allcarsincompetitionmustbepaintedorwrapped.Advertisinggraphicsarepermittedonthe
body.InordertobeeligiblefortheNMCAofficialcontingencyprogram,allcontingency
sponsors’decalsmustbeeasilyvisibleandlocatedontheoutsideofthevehicle.Failuretodo
socanresultinthedriverforfeitingallclaimedcontingenciesforthatparticularevent.The
NMCArequiresthatallentriesrunthefollowingdecals:
1. NMCAWindshieldBanner:Decalneedstobelocatedonthetopofthewindshieldor
justabovethewindshieldlocatedonthebody.
2. NMCADragRacingSeries:Decals(2)mustbelocatedoneachsideofvehicle.Eitheron
thesidewindowsordecalscanbelocatedonthebodyrightbesidethesidewindows.
3. ClassSponsor:Decalmustbelocatedonthepassenger’ssidelowerportionofthe
windshield.
4. VPRacingFuels:OfficialFueldecals(2)required.Mustbelocatedoneachsideof
vehicle.(Inacontingencydecalmanner)
5. AerospaceWinnersCircle:Decals(2)mustbeprominentlydisplayedoneachsideof
vehicle.Failuretodosocanresultinthewinningdriverforfeitinghis/hersWinner’s
Trophy&Payout.
6. Class&CompetitionNumbers:Numbersmustbeeasilyvisible/legibleandlocatedon
thefront,back,andbothsidewindows.
ELECTRICAL:8
BATTERY
Amaximumoftwobatteriesisallowed.
IGNITION
Anybatteryoperatedignitionsystemanddistributordrivesystemispermitted.
STARTER
Allentriesmustbeself-startingwithanon-boardstarter.
MASTERCUTOFFSWITCH
Amastercutoffswitchismandatory.
SUPPORTGROUP:9
COMPUTER/DATARECORDERS
Computer/datarecordersarepermittedandmuststandaloneandtobeonlyusedfor
informationgatheringpurposes.
BRACKETRACINGAIDS
Theuseofanybracketracingsaidssuchasopticalsensors,delayboxes,shutterboxes,throttle
stops,etc.areprohibited.Theuseofanydevice(electricalormechanical)thatallowsadriver
toascertainthepositionoftheirvehicletothestartinglineisprohibited.
PRESSURIZEDBOTTLES
Amaximumofonepressurizedcontainer(excludingnitrousandfreshairsystems)pervehicleis
permitted.AllpressurizedbottlesmustmeetD.O.T.1800lbminimumspecification.
TOWVEHICLES
Theuseoftowvehiclesispermitted.
CREWMEMBERS
Eachcrewmembermusthavetheproperstartinglinecredentialsandmustwerematching
attire.
DRIVER:10
DRIVER
Thedriverwheninthevehicle,fromthereadylineuntilthevehicleissafelystoppedonthe
returnroad,isrequiredtohaveallsafetyrestraintsystems(includingthehelmet)onandbe
securelyfastenedinthevehicleatalltimes
CRENDENTIALS
AValidstateorgovernmentissueddriver’slicensebeyondalearner/spermitlevelis
mandatoryforcarsrunning10.00orslower.AvalidNHRAcompetitionlicenseismandatoryfor
carsrunning9.99orquicker,ataNHRAMemberTrack.AvalidNHRAoranIHRAcompetition
licenseismandatoryatanIHRAMemberTrack.
Note:Itisultimatelythecompetitor’sresponsibilitytofamiliarizethemselveswiththeNMRA
classrequirementsaswellasallNHRAsafetyrequirements.Thecompetitoragreestheybear
theultimateresponsibilitywhenitcomestosafetyandhowitcomplieswiththeNMRAand
NHRArulebooks.Thecompetitoralsoagreesthatnooneelseotherthanthecompetitorisin
thebestpositiontoknowabouthowtheirparticularracecarhasbeenconstructedandhowto
safelyoperateit.