stock SE muffler vs. Flowmaster ?

[93nut]

Does anyone know if there is actually a performance gain by replacing the rear muffler alone or is it only sound and looks? I have a 2002 9-3se NORDIC stage 3+ with all the exhaust hardware to match. 3" downpipe and race cat. I am coming up on TUV or inspection for Germany and Flowmaster muffler's are forbidden here. I have to put the stock muffler on for inspection. Would I loose HP by just leaving the stock muffler on after inspection is over?

[crazybrightman]

if you have replaced the d/p and centre section then fit a standard silencer to the rear you will create a restriction. how ever if you still have the standard saab centre section you wont notice any differance.

[93nut]

Originally Posted by crazybrightman

if you have replaced the d/p and centre section then fit a standard silencer to the rear you will create a restriction. how ever if you still have the standard saab centre section you wont notice any differance.

If the middle section is only a striaght through pipe with resignators as sides, how is it restrictive? The stock muffler( while larger) is also a straight through pipe with baffles on the sides of the pipe. I am trying to understand how it is restrictive. I can put a flex pipe in one side and it slides effortlessly through and out the other side. and the middle section just looks like a gutted cat. School me

[Cpenning623]

So your system looks like this?

turbo---3" DP--(race cat)-----(no resonator)-----flowmaster----tip.


I think you WOULD lose a little top end. Stock is very restricitive compared to an aftermarket flowmaster. Can you post up a vid of what your flowmaster sounds like? I've never heard any muffler thats not straight-thru.

is your flowmaster design straight thru or baffled like

>>>

[JK]

Why do people always say that the stock stuff is restrictive?!?

Has anyone ever cut one apart? There is just a perforated tube going STRAIGHT THROUGH, there are no baffles, no chambers. Its small-ish, like 2 3/8" but I hardly think its restrictive other than maybe if its old, rusted out and collapsed.

As far as flowmasters, most, if not all of them are baffled/chambered in design.

[JZW]

Cut apart? We have measured back pressure and knock on them

We also found the flowmaster to be more restrictive than the magnaflow! Gained 2-3psi on same sw with that change only and the knock levels were lower too!

Many people and companies have tested the back pressure and flow of these mufflers and when you put a magnaflow on the car and pick up psi and spool, well its a no brainer...

John

[JK]

Bla bla bla. What is the back pressure on a new/good OEM vs Flowmaster or magaflow?

[93nut]

Originally Posted by JK

Why do people always say that the stock stuff is restrictive?!?

Has anyone ever cut one apart? There is just a perforated tube going STRAIGHT THROUGH, there are no baffles, no chambers. Its small-ish, like 2 3/8" but I hardly think its restrictive other than maybe if its old, rusted out and collapsed.

As far as flowmasters, most, if not all of them are baffled/chambered in design.

The muffler is brand new. Made by Walker and I had suspisions that other than looks and sound, that the Flowmaster is more restrictive because it is not a straight through muffler like the stock muffler is. The flowmaster is just smaller and louder.

[93nut]

I was looking for a dyno or flow chart but haven't found one. My but dyno says the stock muffler gives me more torque. Well, thanks for all the replies.

[JZW]

Originally Posted by JK

Bla bla bla. What is the back pressure on a new/good OEM vs Flowmaster or magaflow?

More

Its an easy thing to test. Take a tech2 from a shop and test the knock level with stock muffler or mufflers and then put a magnaflow on there and see what the knock level is after the swap.

Same with the back-pressure. See what you're boost is with the stock muffler and then put a good magnaflow on there and see what it is then. We saw a 2-3psi increase in boost from swapping the muffler only...

John

[liketheword]

Originally Posted by JZW

More

Its an easy thing to test. Take a tech2 from a shop and test the knock level with stock muffler or mufflers and then put a magnaflow on there and see what the knock level is after the swap.

Same with the back-pressure. See what you're boost is with the stock muffler and then put a good magnaflow on there and see what it is then. We saw a 2-3psi increase in boost from swapping the muffler only...

John

This is why only a straight pipe should be considered for the whole exhaust system.



The stock exhaust does quite well for performance as long as you have the dp setup already. If you have concerns about back pressure remove one of the 2 mufflers and call it a day before you spend your time and money for next to no gain.

[93nut]

Originally Posted by JZW

More

Its an easy thing to test. Take a tech2 from a shop and test the knock level with stock muffler or mufflers and then put a magnaflow on there and see what the knock level is after the swap.

Same with the back-pressure. See what you're boost is with the stock muffler and then put a good magnaflow on there and see what it is then. We saw a 2-3psi increase in boost from swapping the muffler only...

John

I thought a T7 ecu would lower boost to provide the same amount of power if the back pressure was lowered. I would think that such a smart ecu would raise boost to compinsate for the power LOSS. Thats the way I see it. Maybe I'm wrong. IDK. German Saab stealerships will not let me play or handle the tech2 for muffler testing. The stealership always wants my car to go under the knife to figure out what all has been done. Nordic tuning boggles thier minds. LOL

[93nut]

The difference in performance was only different until the ECU re-adapted to the new muffler. After a couple of good WOT autobahn runs, the factory muffler was stinking like burnt metal and the car is now boosting the same as before, just quieter. LOL

[aero93]

i ran a viggen muffler with my stage 4 setup, and loved it

[dan-the-kid]

I got a 3" waiting to be put on....

JP DP, Magnaflow cat, straight though, to a magnaflow muffler. My guess is that its gonna sound sick.

[Saab9-3se]

Why is the flomaster illegal in Germany ?

[DViggen]

Sound restrictions probably. I also don't think they have undergone the TUV testing.....

I know that with my Jetta, I was able to get away with a Borla muffler for TUV.....I failed with a Magnaflow muffler.

Originally Posted by Saab9-3se

Why is the flomaster illegal in Germany ?

[93nut]

It's not TUV approved and their is no DB rating for a specific auto make. It's only rated at LOUD. LOL

[jonny72888]

how does the saab sport muffler compare to the others, mayb you could use that?

[JZW]

We tested the saab sport 2.5" against and full 3" with magnaflow and got similar results, less knock on the full 3" system.

That is the bottom line, less knock levels read is always good

What that would mean for t7 is that it would have to work less hard to make mass air requirement. Its still a good thing to have for performance in my opinion.

I am sure you can get away with a stock muffler and good dp, but why not go the extra step and not just "get away" with something and have a full 3" with a good flowing cat and a good muffler?

If there were no benifits, race cars would have full cats and mufflers and those turn out cat and muffler by-pass valves would not exist.

Check out Nicks test, open dp and full system.
http://genuinesaab.com/gallery/Gt307.../compareopendp


John