Saab Link Forums banner

stock SE muffler vs. Flowmaster ?

4K views 24 replies 13 participants last post by  93nut 
#1 ·
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?
 
#3 · (Edited)
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
 
#4 ·
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

>>>
 
#5 ·
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.
 
#8 ·
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.
 
#6 ·
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
 
#10 ·
More:cool:

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
 
#13 ·
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
 
#15 ·
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.
 
#20 ·
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:cool:

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/Gt3071-500hp/compareopendp

John
 
#21 · (Edited)
I guess the only problem that might be effecting performance would be the bottle neck effect at the stock muffler because everything else is 3" pipes. Once again, AFAIK, only stock, OE mufflers are alowed for saabs here in Germany. Thats why I have to have the original muffler on the car. Not my choice, just the LAW!
 
#22 ·
Yea, we live with what we can work with and I was not arguing with you, more the other people that were saying the stock muffler is just fine.

I thought the ferrita was ok since Maptun sells them, what about borela?

Is it just for inspection? Can you run stock for inspection, then bolt up a ferrita or something for the rest of the year or two?

I have to put my stock ecu, full cat dp in and stock fuel injectors to pass emmisions here in my state, Colorado USA. Then after I pass I have two years before it has to be tested again. I then put the big fuel injectors back in the car, the free flow dp and tuned ecu with lots of timing and fuel...

Good luck,

John
 
#25 ·
Inspection is every 2 years and yes I did just put the stock muffler on only for inspection. I had to buy a new OE muffler this year for inspection because my original was rusted out with holes. It's pretty easy to swap them, 2 bolts and three hangers. I have the Flowmaster muffler welded to a section that matches the pipe fittings so it bolts up just like the stock muffler. I live in a gated neighborhood and the Flowmaster was starting to get me dirty looks by the older people on my block. I think I own the oldest car in my neighborhood. :eek:. As for after market mufflers that are allowed for Saab here in Germany, Hirsch has the market cornered all by itself. Damn near 400 Euros just for thier muffler so I can have legal paper work is not worth it to me. :evil: I ran the Flowmaster all year anyway but if I wreck on the Autobahn and they do thier manditory inspection of my car, I will get F@#*ed for every aftermarket piece of equiptment that I don't have GERMAN paperwork for. OUCH!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top