running no muffler
 

has any one done it and is a safe idea?? thanks

RE: running no muffler
 

it will be fine, just loud

RE: running no muffler
 

VERY Loud!

RE: running no muffler
 

I am sure people have. On this forum I don't know.

But what I do know is this...

1. It could be illegal in your state.
2. It is going to be extremely loud.
3. If you think your going to gain power, I doubt it. Possibly loose power if anything.

If your looking for sound why don't you do a catback system? Or if you can't afford buying a catback system or having one made for you then why not install a performance muffler. You wont gain much if any power from it but you will gain sound.

RE: running no muffler
 

In most cases, it will be Illegal, it will be VERY loud and you WILL Lose Power.

The exhaust system is designed to run with some back preassure and without it the car, when you step on the gas, will seem to fall on itself trying to get out of its own way.

Volvo exhausts can be expensive, over $500 front to back as it is a one peice system,but Im looking into a system built by Midas because I want to find out if I can piece components together.

[sm=icon_cheers.gif]

RE: running no muffler
 

Lack of back pressure is not good for exhaust valve and seats.

RE: running no muffler
 

Not to cloud up this thread but we need to consider the fact that the exhaust system on a turbocharged car is more about sound than about back pressure. At low rpms and low boost you will notice a loss of torque from the lowered back pressure but at higher rpms and into the boost you should actually see more power.

In addition most performance mufflers are of a "straight thru" design and would look just like a straight pipe as far as back pressure is concerned.

After doing some crazy math based upon some assumptions about the temperature and density of exhaust gases I have come up with the following conclusion.

Removing the muffler and replacing it with a pipe of same diameter and roughly the same length as the muffler would result in about a 5% increase in flow capability for the same pressure. Since the volume is determined on the engine/turbo side that means than the backpressure would be reduced by about 9 or 10 percent. This would have very little effect on thevalvetrainand maybe a loss of like1 or2 ft/lbs of torque when not operating under boost. The increased flow capacity would result in probably less than 2 or 3 PEAK horsepower increase.

What you will have though is like an 18 decibel increase in sound pressure. (3 decibel increase sounds TWICE as loud) So it will be roughly 10 TIMES LOUDER.

Compare that method to a simple CAT-BACK system with a straight thru muffler and a 2 1/2" diameter versus the stock 2 1/4" and you get over a 25% increase in flow and a 30% decrease in back pressure. Resulting in maybe a 4 or 5 ft/lb torque loss down lowbut as much as 10 or 12 extra HP in the upper RPM's. In addition the significantly lower back pressure has other desired effects like cooler exhaust temps and quicker turbo spool up.

Best way to illustrate this point is look at the commonly seen turbocharged vehicles like trucks and busses, ever see a 2" exhaust on a truck? But how many trucks and busses are as quiet as a Volvo?