On my GT, I'm running a "home made" system which consists of 1 3/4" pipe
from the "Y" connector (just behind where the two down pipes join)
feeding a 13" glass pack, and exiting through a 2" tail pipe that makes
the absolute minimum number of bends, etc before exiting at the stock
location under the rear valance.
My interior noise level is very low (as regards exhaust - misc.
rattles,squeaks, etc not being part of the discussion!) All I hear is a
subdued rumble from the rear.
As for "ALL" tube headers leaking, I'll have to disagree with that
assesment. If it were true, the MG RV8 would have had cast iron headers
instead of the tube headers.
It has more to do with the design, quality control in manufacture, and
most important, the care taken when installing the system, which will
determine if leaks occur.
There may be an inherent higher level of "noise" with tube type headers,
simply because they do not have the mass that the cast iron exhaust has,
which will tend to absorb quite a bit of exhaust noise.
On Mon, 20 Apr 1998 21:07:22 -0400 Tom Buchanan <email@example.com>
> I own a MGB-GT, a beautiful noisy (interior noise) LBC. (You
>owners calm down! When your top is up or your detachable top is on,
>just as noisy!) I would like to add a free flow exhaust to my car, but
>far as I'm concerned the noise level of the original exhaust system is
>limit of what I want to endure (I like to talk to the passenger not
>I read Peter Burgess' book on power tuning the MGB. A very good book
>answered MANY questions I had.
> Both Burgess and John Twist strongly suggest keeping the original
>iron exhaust manifold. Twist insists that ALL after market tube
>leak and both these guys determined these headers are noisy compared
>original cast iron manifolds and with no noticeable increase in power.
> Most, if not all full flow exhaust systems use only one muffler (I
>understand that in the original system that the front silencer reduces
>low frequency noise and the rear resonator reduces the unpleasant high
> I want to be able to increase my SU intake flow but, all this tells
>that any full flow exhaust system must be louder than the original
> I would like to be able to keep down the noise, preserve the
>sound, retain the cast iron manifold, AND be able to take advantage of
>increased intake flow. And if you can arrange it, a gorgeous blond I
>whisper to. That's all I want.