Im just after fabbing up a bit of an exhaust for my GS300 (98, 3.0 non turbo auto)

Basically its still a standard system, with the rear backboxes deleted and replaced with 2x 2.25inch pipes each side, M5 style. (i know the M5 rear sections are silencers, im just giving an example of what it looks like on the car.)

Anywhos, it sounds class, but i think its a little bit loud inside the car. Few of the lads who were behind me earlier though, reckon its not. Which brings my questions:

Will it quieten down when it gets a bit coked up?



The main thing im wondering about is that, on the drivers side i made a bit of a bollox of it and the pipe is wedged up against the subframe mount.. its not rattling, its jammed up there solid, i just didnt have enough ramp time to fix it.. Im thinking maybe is the exhaust resonating through the car from where its contacting the body and making it much louder inside the car than out?

 

Any time the exhaust touches the car it will resonate through out the car. As for it quieting down as it gets "coked up" - in mufflers with matting matterial in them (fiberglass is the usual material) the exhaust (carbon deposits) do tend to make it a bit quieter. Doesn't really work for pipe though.

 

i have already experimented with this a lot. you cant get rid of that sound inside the car with the pipe going all the way back. the sound ins bouncing off the road up into that empty cavity where your muffler was. best solution i found was to exit the exhaust out the side as quickly as possible. mine turns out right after the rear tires. i hung my tips (now fake) in the orig. spot because it looked funny without them. clean sound outside the car, none inside.

ps. you cant have vibrating parts touching the frame.......or any other solid object for that matter.