Anyone know where these silencers are located? i have a 99 5.9 and also am interested in free horsepower gain as im sure everyone is lol.
"Silencers" are in the air box system! All the mfgrs do this so that the passengers in the vehicle do not hear the air rushing into the carb or throttle body!
Usually they are a baffle system that restricts the airflow, like the baffles in a muffler on the exhaust system.
Changing over to a freer-flowing intake filter, with a cold-air intake is what they speak of ---- but don't fall into the trap of the K&N system if you like your engine and want to keep it for a while.
AND if you have a fuel-injection system, they don't like oil-wetted intake filters, since they screw up the MAF sensor!
GM has said they will void warranties on engines that have been converted to them! Be advised, you decide!!