Navigator exhaust

[1badd7]

I have a 2004 navigator with the 32v Intech motor, am looking to do a custom exhaust system (true dual) from the manifolds back eliminating the 4 cats and going down to 2 cats. I've done a system like this before on my 01 but wound up being a little too loud for me, I'm thinking it's largely because I used a Spintech muffler. My question is has anyone used a muffler that's pretty free flowing but still remains pretty quite?

 

[Moto Mel]

I have a 2004 navigator with the 32v Intech motor, am looking to do a custom exhaust system (true dual) from the manifolds back eliminating the 4 cats and going down to 2 cats. I've done a system like this before on my 01 but wound up being a little too loud for me, I'm thinking it's largely because I used a Spintech muffler. My question is has anyone used a muffler that's pretty free flowing but still remains pretty quite?

I've been considering a similar system but I have come to the conclusion that a larger diameter pipe from the manifold exhaust pipes (Y pipe) back would be a better thought due to space restrictions, Then split the pipe near the rear end to have duals at the end. I'm going to look at the exhaust on a F 250 7.3 diesel PUT for comparison. Removing the cats will increase noise levels.

 

[1badd7]

I found that the 32v motor is really restricted by the 4 cat system and tends to really "wake up" when it's taken down to a 2 cat system

 

[micahs97m8]

This is in the future for my wife's car. please provide updates on what you ended up using. Going to do full header back exhaust and open intake.

 

[chp10_8]

If anyone is interested (still) deleting the two rear cats and installing a mandrel bend if your keeping a single exhaust is the way to go as well as deleting the rear resonator. this alone will boost up torque, HP,and MPG. Not to mention release a lot of back pressure issues!!!! GL