9 replies to this topic

[Ernie Jr.]

Just wondering is a heat wrap around the tube that goes to the air filter legal. We saw it on a car a customer got and was wondering if its legal.

[Doug007]

From NASA 2012 SM rules:


13.2.
Air Filter

13.2.1. 1600cc engine powered vehicles may use a cone-type air filter assembly. The air filter
assembly may include integrated or attached components that may serve the purpose of shielding ONLY
the air filtration element and air intake tube prior to the AFM from radiant engine heat. Any
pieces attached to the air filtration element or intake tube may extend no further than 1.5 inches
in any direction from the filtration element or from the air passage within the intake tube and may
not shield, overlap or protect the AFM itself from
engine heat.

[Ernie Jr.]

From NASA 2012 SM rules:


13.2.
Air Filter

13.2.1. 1600cc engine powered vehicles may use a cone-type air filter assembly. The air filter
assembly may include integrated or attached components that may serve the purpose of shielding ONLY
the air filtration element and air intake tube prior to the AFM from radiant engine heat. Any
pieces attached to the air filtration element or intake tube may extend no further than 1.5 inches
in any direction from the filtration element or from the air passage within the intake tube and may
not shield, overlap or protect the AFM itself from
engine heat.

What does it mean that 'may extend no further than 1.5 inches in any direction from the filtration element or from the air passage within the intake tube and may not shield, overlap or protect the AFM itself from engine heat.'

[wheel]

It means you can't wrap the tube with 3" of insulation that does more than insulate the tube. You cannot wrap the AFM with insulation, and the tube insulation cannot perform the function of insulating the AFM.
wheel

[Ernie Jr.]

But you can put a thin heat wrap around just and only just the tube.

[LarryKing]

Yes.

[Ernie Jr.]

Thank you.

[LarryKing]

Like you need more HP.

[Ernie Jr.]

yeah lol

[dtfastbear]

It also allows for a heat shield between the air filter and the engine to protect the filter from radiant heat. The reason for the 1.5" inch specification and the "may serve no other purpose" wording is to keep someone from utilizing a tortured interpretation of the rule to create a ducting device that they claim is for heat shielding but in reality it extends all the way to the front of the car and is directing cool air in to the filter.

My unscientific butt-dyno tells me that on hot days, having a thin heat shield between the filter and the engine and the wrapped intake tube keeps the car from falling off in the latter part of a 30-40 minute race.

Cheers,

Dean