I am getting back to work on my 1996 850 N/A. I fixed the problem of the airbox sensor not opening up the main intake to the box. Car pulls much harder, feels as it should.

I am thinking about putting a less restrictive, better sounding muffler on the car. My old 740 had a straight pipe back into flowmaster muffler. Sounded great. I don't want to elimiate the cat, so I am thinking about just doing the muffler. However, I know the non-turbo engines need adaquate back pressure. I don't want to mess that up.

now the problem is that flowmaster doesnt make a specific muffler for any volvo. I am finding a few diffrent mufflers on craigslist, all are going to require diffrent fabrication, I found one that has a 2.5" inpipe. that muffler is for a V8. Is this going to not have enough backpressure? does that cat. converter itself provide most of the backpressure, or will a non-stock muffler really change the backpressure? Can I put just about anything on there withen reason or do I have to really keep things as close to normal as possible to avoid problems?

any help is greatly appreciated.

Jeff

any advice

 

put what ever you wont on....the more freeflowing the muffler the louder it will be.
you will gain good topend power with freeflowing even on an NA.....just dont go to big on the pipe diameter.

 

I got a much better look yesterday. The stock muffler is a strange one, its one of thoes "pancake" style ones. The pipe goes in at a sort of sideways angle too, which is going to make things more difficult then I thought.

I have hearda bout an aftermarket exhaust system for the 240s that you can get from the dealer for about $250. If this is real and not a myth, Is there anything like this for the 850?

 

not sure....you can buy cat-back systems from somw of the sites listed here: https://volvoforums.com/forum/general-volvo-chat-5/volvoforums-resources-thread-7317/
As well as other performance goodies. Custom is also an option....

 

so, I think I found aplace that can get a decent performance muffler in for a good price.

however, I would really like some imput on what lowering the backpressure on the N/A 5 cylinder engine will do. I am a little hesitent to change the backpressure even a little,but I am sort of resoning that the stock muffler is designed for maximum queitness, not overally effeciency, and that a stock muffler with 150 thousand miles on it is even less effecient due to carbon buildup. changing it out and freeing up the airflow a little may infact bring it back to the level of backpressure of when the car was new, just slighlty lower as I am not touching the cat.

but causing the fuel/air mixture to be sucked out even a little is the last thing I want. At 168 horsepower(if that) even losing a little would really be depressing. Does anyone else think I am fine as long as I keep the pipe the same size and don't do anything really drastic?

car is due to be in the shop tomarrow so I need to make up my mind... thanks

 

you should be fine.like you said,you are not touching the cat or pipe.

 

Just a muffler wont really matter if you aren't touching the resinator. That provides more than enough, so if you are just doing the rear it will be fine, just louder.

Here is my dad's 540i (V8) with high flow cats, stock resinator and no muffler:
http://s426.photobucket.com/albums/p...t=100_9229.flv

Car runs as good with out the muffler.