Muffler removal
 

I was thinking about testing out whether or not my muffler was helping my fuel efficiency or harming it, and was wondering if I should take it off next tank just to test and see.

I'm not gonna worry about the noise violation problem, I live in such a rural area, If I got caught I'd most likely get a verbal warning to get it fixed. Not too bad since I've already been yelled at for having my Sub woofers too loud.

Think I should do it? I checked out my pipes, and they look to be mandrel smooth bent, and I've got such high gears (low ratio), that my exhaust probably needs more backpressure, but I'm willing to try and see.

If it works in favor, I might just pick up a more free flowing muffler, if not, I might get a washer to put more backpressure on the exhaust and see where that goes.

I do about 1500ish rpm's at 55mph, at 60 I do about 1700. Need more backpressure? Maybe, maybe not?

Take it off, backpressure does nothing for you.

Except keep you sane ... LOL The noise may be unbearable, definately not a chick magnet ...

Exhaust gas velocity is a good thing, this is accomplished with small (restrictive) pipes. Big restrictive pipes accomplish nothing.

Sorry, but I'm gonna have to say this is wrong

It's a common misconception, Backpressure does nothing for you IF YOUR FULL THROTTLE RACING!!

you need backpressure IF you have AN EXHAUST SYSTEM AT ALL, Or else economy is screwed up.

exhaust basics
Here's some things about exhaust basics. Notice how the plume distances are important? we need backpressure at cruising speeds, but not during acceleration. For HP we need no backpressure, for efficiency we need backpressure.

Jeep Probably did, considering it made an engine with all the torque 3k rpm's and lower, anything above 3k makes the engine wheeze. capable of towing 5k lbs.

Removing your muffler does help because the noise will drive you insane if you try to accelerate to fast, you can hear how the engine is running so much better and if it starts to run rich at all it gets really loud! so this is not an accurate test as your driving style will drastically change.

Take it off, record some data and prove me wrong!

Shouldnt be too loud, how many cats are on it? Resonators.

I personally believe in free flowing exhausts. But look at what I drive. The turbo provides all the backpressure the engine could ever need.

TEST IT! Give it a go, it'll be fun. I'd test without the muffler, then go with the washer with a relatively small hole and slowly drill it larger as you test to tune it.

On a side note I replaced the muffler on the TDI with a straight pipe when the muffler broke off. It did not make a noise difference at all. But then again the turbine itself makes a pretty good job at muffling already.