M3 exhaust

[peter 0]

Can any of you clever guys out there tell me if there is any advantage in removing the catylic converters and the small front muflers from my E36 M3. or are the existing converters high flow models.

[Dnz 0]

No cats is always better. They wont be high flow cats.

Removing them is completely illegal.

[Guest Spargo]

Removing them is completely illegal.

Since when?

[DCEIVN 0]

Would be louder & deeper note... Depends on whether or not you have a factory or "performance" muffler.

[Dnz 0]

Removing them is completely illegal.

Since when?

Im wrong. I forget most stuff i read is from the US.

In which case, take them out! Hoorah!

Take that greenies

[kerrynzl 3]

Hey I not sure if removing Cats is illegal yet [smogging cars isn't a WOF requirement] most modern Cats are high flow they are a matrix coated with a Platinum/Rhodium Ceramic designed to store heat [they glow white hot] to help afterburn unburnt hydrocarbons & 2xCO+ O2=2xCO2 [they need heat & oxygen to work correctly] any removal of a restriction in the exhaust [& intake]helps as long as it doesn't bleed of cylinder pressure] I remember seeing a USA test on high performance mufflers where an engine made more horsepower with their brand compared to OPEN HEADERS. what they did was grind a cam so the engine required excess backpressure from the muffler so it didn't lose cylinder pressure [therefore making more power with mufflers] Remember most Mods designed to increase Volumetric efficiency only work when the RPM goes up [torque x RPM] look at F1 engines [18000 rpm+]