2005: The BIG change...
Okay, now this is where things got a little crazy. Actually, this is where things
got a LOT crazy. And it all started at the time when the car was up on the lift at the
shop where the suspension was getting looked at. A suggestion was made about procuring a
set of original style exhaust outlets: chrome-like splitters on either side, instead of
the generic Camaro-style tips that were on the car for who knows how long.
One thing that I learned with my experience of trying out that ratty '77 Trans Am
(described elsewhere) was that a part of me wanted a car that exuded a muscular attitude.
Part of the attraction to that other car was the Flowmaster exhaust system in combination
with the slightly warmed over 400 engine (possibly an original W72). So along with the
original exhaust tips, I asked to get a muffler swap to something more aggressive... much
more aggressive, because although it was the biggest motor in my stable, it was the most
quiet.
The big problem: once the candidate muffler showed up at the shop, they informed me
that they had just tried an identical muffler on a 350 small block... it was QUIETER than
what was on my car. It was tough to find a muffler that would fit the transverse setup of
the original piping, and I was not looking into losing my ground clearance with large
underbody mufflers as well as my total reluctance to embrace the "Flowmaster" sound.
This is where my knowledge of F-body trivia came in and saved the day: the exhaust on
the base 400 (as installed in my car) was routed through a Y-pipe from the manifolds into a
large pellet-style catalytic converter and then routed down a single pipe to a transverse-mounted
muffler behind the rear axle, and then out to the twin splitter exhaust tips. On my car, the
converter was long gone and replaced with a straight pipe, and the original muffler and tips
were lost and replaced with a generic transverse muffler with Camaro-style outlets. The W72
version of the 400 benefitted from a semi-true-dual exhaust system: from the single catalytic
converter, the exhaust branched into two separate paths and passed through two resonators and
out to the twin exhaust splitters. No mufflers: the idea was that the converter quieted things
sufficiently and the resonators simply shaped the sound.
I decided to do something similar to this setup, with a slight variation: from the
manifolds, the exhaust path maintained a true dual setup all the way back, as seen above.
Two small resonators were used to maintain ground clearance, and the original style splitters
were installed.
With no converter to pre-quiet things down and teeny weeny resonators, the sound is
something extraordinary. Now that it has had a few miles to mellow out, it ranges from a
mellow bark at slow cruising speeds to a roar at part-throttle acceleration to Total
Armageddon at WOT (the window crank handles will rattle with the accelerator to the floor!).
Gentle acceleration from a complete stop in a residential area
Cruising down a highway access road at 80 kph
Merging onto a highway at 70 kph
Revving in a parking lot
This completely changed the character of this automobile. For 2006 I am expecting to
install an H-pipe at the vicinity of where the transmission mount is located, in an attempt to
mellow out the sound a bit. At highway speeds, the sound is angelic to my ears but at gentle
acceleration I think it needs a bit of mellowing out.
While I was on a roll, I decided to try and tackle the worn motor mounts as well, but
a combination of unbelievable ambient heat and humidity coupled with the fact that the motor
mounts had been installed upside down made it very difficult to perform this task myself. For
2006 I plan to have a powerful A/C unit installed in the garage, and with a little patience I
might be able to crack this problem.
These changes were enough to make me look forward to using this car as often as
possible on my commute to work. With all the effort over the past years, the car went from a
low of 10 mpg to its current 18 mpg commuter status... impressive considering the engine's
age, old tech, and just plain overall size!
As long as it was sunny, I looked forward to hopping behind that familiar dash and
grooving to that exhaust note for 30-40 minutes on my way to work. The exhaust note at 100-110
kph sounds just like it was pulled from a Smokey and the Bandit soundtrack, during the dialogue
scenes in the car at highway cruising speed.
