Exhaust baffle?

Never mind.  Found a ton of stuff on YouTube and something should work.  Mostly stuff for cycles but exhaust OD is very similar.  I will post video of B4 and after once I get them installed.

There is no such thing as "inadequate back pressure". Backpressure is always detrimental to the engine perfomance. If your exhaust diameter is too large, exhaust velocity decreases which causes a loss of torque. To keep the velocity higher we must use smaller diameter pipes. These smaller pipes do increase backpressure, but we accept that tradeoff to get the increase in torque. Backpressure is a symptom, not the goal.

 

What is the size of your engine and exhaust diameter? That will tell you whether things are missmatched or not. But I don't think a mismatched engine and exhaust would cause the symptoms you are describing unless you're grossly mismatched like a 1 3/4 exhaust on a 1600. But the correction for that is to get a different sized exhaust. Sticking a banana in your tailpipe isn't going to help.

 

Popping on decel is most likely an exhaust leak. Other things, in no particular order: Carb either too rich or too lean can also cause these symptoms. Falling over on sudden throttle, it could be a bad accelerator pump or plugged jets (typically idle). Could be incorrect timing or timing advance gone bad as well. Might as well check valve lash and check for intake leaks too. Or it's a combination of these.

So back pressure is never an issue, eh?  Well I suggest you take the muffler off your car and tell me how much better it runs.  As a kid we did  that all the time for the enjoyment of our neighbors but the fact that the car ran like crap eventually took the fun out of it.

I don't think that is what Justin was trying to say. My guess is that he means there is a delicate balance between exhaust velocity and torque. If you post your particular engine configuration there are a host of guys on here that point you in the right direction.

 

In-the-meantime, start your engine, have someone block the exhaust with a rag or a towel, crawl up under the car and feel around the exhaust joints for leaks. You'll probably find one if your car is popping or backfiring on deceleration. 

 

I'll tell ya, sometimes these problems can be... exhausting.

 

Many times people around me wish that I had less velocity, a baffle, or even a plug depending on what I ate the previous day.

Of course. Removing the muffler changes the tuned length of the exhaust system. That alters how the engine performs.

Yes yes - like blowing through the mouthpiece of a tuba without it actually being attached to the horn.

 

Man I love this site. It really makes me ponder things...