heat box

[Markr44]

I was wondering does any buddy know what will happen if you close off the air going into the muffler my though is to take the heat away from the fire wall when heater is not being used. It just seems like a lot of hot air in the summer time dumping on the fire wall.

[JonJay]

It is not recommended as the muff, and exhaust pipe need cooling air to prevent overheating and damage to one or the other. I have never tested the theory though. Might be interesting to throw some sensors in there and see.

[Bill.Peyton]

I spoke with Vettermen about this. He said it was ok as long as the heat muff was removed and a heat shield was installed in its place to protect the engine compartment.