Re: E39 - Why are exhaust systems so expensive??

[alex.fadeev@xxxxxxxxxxx]

"Dave Castine" <davecastine@domain.elided> wrote:
> I buy into the theory of "it's not how much you make, but how much
> you keep" - I do ok in the $$ dept, but I'm having a VERY hard time
> justifying $600 for a muffler.

Dave,
Most well-built aftermarket stainless steel mufflers sell for $500+
regardless of the make/model of the car they go on. Just like most 17+"
forged wheels sell for $400+.
That's just the cost of entry. Whether or not that $500+ aftermarket
exhaust introduces power gains or looses is an entirely separate
question. A rag (European Cars?) ran an aftermarket exhaust dyno
comparison on an OBD-II E36M3 and the best of the dozen+ systems produced
a high RPM gain of up to ~5 horses at the expense of loss of torque and
HP in the mid range. On a very conservatively rated 240 crank HP engine,
that's a 2% max increase in power. Or barely outside of DynoJet's margin
of error. Draw your own conclusions.

> I'm a car guy - I grew up building Chevelles, Mach 1's, and 340
> Dusters...went to college, got married, bought a house, and had a
> couple of kids. I do all my own maintenance, brakes, detailing,
> etc. and I'm now thinking of upgrading my car's performance. $600
> for a muffler? WOW...

Dave, you are lucky your car has only one exhaust ;-)
Seriously though, exhaust should be one of the last things you touch on
the car. The ~$200-300 factory exhaust is excellent in terms of flow
through as well as well as longevity. My old E30 exhaust lasted 9 North
VA years and fit perfectly. The track E36M3 is on its 8+ year old OE
exhaust. I may eventually replace it with a lighter big bucks aftermarket
muffler if it ever rots out (not likely now that I live in TX).

> Can you help me to understand why I shouldn't go to my neighborhood
> custom exhaust shop to fabricate a flowmaster muffler for my car,
> including stainless mandrel bent pipe and tips for $250?

You most certainly can. However, a big ass mega-free-flow exhaust may be
a performance DOWNgrade. I'm not an exhaust flow specialist, but from
years of reading this and other forms it takes more than a WAG to get a
performance gain over an OE BMW exhaust.

HTH,
alex f

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