Exhaust Question

[gabod7]

Hey, after spendin close to 500 bucks on exhaust in my taurus, i figure it's time to make my Pathfinder a LOT louder than the stock sound now. i had a dual outlet muffler on the bull and im lookin to do the same with the pathy now.i am lookin on ebay and summit racin and other random sites at the flowmaster 40 series mufflers. i want one now, lol.it says the inlet is 3" for the dual outlet 40 series. now, will i have to do anything special to make this fit right? i have a welder and all the necessary equipment to do the job, im just not sure if 3" is to big for the inlet? sorry if this sounds confusin, any help is great, lol, thanks.

[jj big shoe]

I think the stock exhaust from the cat to the muffler is 2" so you would need enlarger pieces to raise the diameter to 3".

 

I'm no engine builder, but there is some relationship between back pressure and torque so going to a 3" inlet muffler might not be as good an idea as it sounds. I'd investigate the performance gains of a 3" system a little more before you spend the cash and possibly get disappointed.

 

When I installed a full exhaust on my '87, I went with 2.25" from the Thorley headers through a Magnaflow cat and into a Flowmaster 50 series ending with a 2.5" tailpipe and it sounds good as well as perked the motor up a lot.

 

Just my $.02

Edited May 5, 2005 by jj big shoe

[88pathoffroad]

Yeah, 3" is too big. A 2.25" or 2.5" single in-out muffler will do just as well, you just won't have two exhaust tips.

[mws]

yup, as they said, going too big starts leading to problems as well. One of the worst is rust problems. The relatively low volume of exhaust gasses our trucks put out just won't fully heat up and dry out a huge volume 3" exhaust system. Cold pipes mean rust breeding grounds!

 

However, you could still use that muffler if you really want it - but use a maximum of 2.5" pipe (2.25" is probably ideal) before the muffler and if going with dual tail pipes, use 1.5 or 1.75" on the outlet side. And lots of adapters.