On 6/15/2011 6:24 PM, Robert Blair wrote:
> Hi Listers, The time has arrived for a new exhaust system on my BJ8. Banged
> up rear boxes are holed/rusted thru - just age and bottoming out.
>
> Would like the List's collective experience. ...
Have given this subject lots of time, thought, money and frustration. Even
read a book called 'Scientific Design of
Exhaust and Intake Systems' (if you ever have trouble sleeping ...).
I'm currently running a system cobbled together from 20+-year-old Ansa pipes
and generic glasspacks. The pipes--where
they haven't been clobbered--are in perfect condition, but I rarely start the
car unless I'm planning an hour or more of
mostly highway driving. It's noisy--somewhere between a stock BJ8 system and a
straight-piped Harley, but surprisingly
quiet at highway speeds. I've wrapped the downpipes--which some claim will
lead to their early demise--but the main
casualty seems to be the front mufflers--I've had to replace them after only
15K miles or so. I believe most, if not
all of the current aftermarket products are glasspacks and not baffled
('turbo') systems (the Ansa mufflers were
glasspacks). The glass/steel wool will deteriorate over a few years; the
extra-hot exhaust gas from my wrapped
downpipes exacerbates the problem.
Have heard--have no hard data--that the longer BJ8 system actually improves
low-end torque (but may limit top-end HP).
Something to do with natural resonances at certain engine speeds.
When I get tired of welding new glasspacks in I will look for a good-quality
mild steel system (I believe Walker brand
has been recommended). Or, Moss has a new, polished SS system that has gotten
good reviews for other LBCs (however,
these are glasspacks and I suspect the packing will be gone before the metal
goes). I would scuff the SS and coat
black. This stuff works very well:
http://www.designengineering.com/category/catalog/design-engineering-inc/exhaust-wraps-accessories/ht-silicone-coating
It needs to be 'tempered' at 400degF--after applying I go over with a propane
torch with spreader. Holds up better than
any paint I've tried.
Bob
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Bob Spidell San Jose, CA bspidell at comcast.net
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