suprawillis

My heater boxes and ducting were removed by the prior owner for weight savings. Additionally, those 45 degree ducts/hoses that connect on the back of the exhaust manifold are also eliminated.

My question is that because some of these components are connected to the exhaust, would it make the exhaust louder? My car is loud as all hell with mufflers or with supercup bypass mufflers and wanted to know if the missing heating components would have an effect on the sound.

Thanks in advance.

pp000830

The path to the cabin through the heater system from the exchangers is convoluted and includes cut-off valves in the foot wells so sound probably does not channel through the system. 993 are loud, to begin with, and most aftermarket systems are designed to make them even louder. I suspect you simply have a loud exhaust system that if it bothers you one can switch out the mufflers for stock ones. Also, check that you have the 3/4" black rubber sound blanket above the engine in the engine compartment. It is possible that a previous owner removed it or replaced it with a thinner one. Another source of sound could be the air intake filter if your's is replaced with an aftermarket one you may have intake sounds contributing to the sound.

Also hard engine and transmission mounts may contribute to noise. Aftermarket flywheels without the vibration isolation mount, I understand, will contribute to a loud drone at certain speeds some find objectionable.

Andy

suprawillis

Appreciate the response, Andy.

JasonAndreas

When they removed everything did they block the openings in the chassis next to the gearbox for the heater lines that run through the door sills? There are two vents (located behind each front seatbelt retractor) from the passenger cabin into those lines. Chances are good the air pressure in the cabin is higher than in the lines so the plastic film "doors" will be open and allow sound to enter directly from the engine compartment.