Any internal combustion engine can quite accurately be described as a breathing machine. Just like
a trained athlete, the key to improving the performance of an engine requires an increase in the
breathing capacity of the machine. Quite simply, increasing the ability of the engine to intake more
air/fuel mixture and exhale the resultant exhaust more quickly, results in greater horsepower/torque
potential. The variety of methods to accomplish this task vary greatly in methodology,
effectiveness, and cost. Generally, bigger dollars bring bigger results, sometimes at the cost of
drive-ability. Our goal with Project 164 is moderate gains in performance without any negative
effect on drive-ability.
The first thing to know about after-market performance parts for the Alfa 164 is that they are nearly
impossible to locate, if they even exist at all. With scarcely more than 5000 of the cars delivered to
the North American marketplace over the five years ARDONA marketed the 164 here, most
manufacturers have ignored this car as an upgrade candidate. Fortunately however, a world-wide
search (not to mention some custom fabrication) has produced a few options.
A six year-old Alfa 164 exhaust system driven year-round in the northeast is on borrowed time. The
weak point of the system seems to be the triangular primary muffler/resonator, found under the rear,
left side door. Mine had an assortment of small rust holes, as did the joint between the pipe and the
rear tailbox unit. Stick a fork in it, it was done; the search for an upgraded replacement system was
quickly under-way.
Admittedly, there are more replacement exhaust systems for the V6 164 than I had initially
expected. Aside from the stock Alfa system (too boring for my purposes), Faza and Ansa supply
complete (center and rear components) systems for the 164. Additionally, Remus and Supersprint
sell "high-end" rear tail-pieces (only), with high-end prices to match. Still not happy with these
options, my search continued beyond the United States borders to the UK, where I found a complete
stainless steel replacement system from AutoDelta, for the princely sum of $700 (before shipping
and import fees) at current exchange rates. Nice, but a bit more than I really wanted to spend.
And so my search continued, this time north of the border to Ontario, where I found a little company called Stebro, which has been in business since 1956 making 100% stainless steel free-flow muffler systems for Italian cars. Initially I was disappointed, as their home page on the WWW had no mention of anything for the Alfa 164. I enquired nonetheless, and promptly got a reply from owner Andy Petschenig that a system could be fabricated for the 164 (they had built a few before), for less than $500. My credit card number was relinquished to Andy within minutes. Eight weeks later a box full of stainless steel parts arrived on my doorstep. The Stebro exhaust is made mostly from type 409 stainless steel, which is very resistant to corrosion and somewhat less expensive to produce (and sell) than type 304 stainless steel. The visible part of the exhaust, the exhaust tip, is made from polished 304. Since my system was custom fabricated, I was able to spec' a 3" oval tip, which I highly recommend over the standard 2 1/2" round tip.
The ease with which the old exhaust system is removed from the car is directly related to how high
you can get the car up in the air. For most of you, I'd suggest jacking the left side of the car up and
blocking it with jack stands. Never rely on a hydraulic jack alone! I have a drive-on lift in my
garage, which enabled me to have both pieces removed within thirty minutes. All that is needed is
an assortment of 13mm sockets and wrenches to remove the bolts which hold the system together.
After un-bolting everything, the two components are simply removed from the rubber hangers; the
rear tailbox is easily removed from the rear of the vehicle.
Before installing the new exhaust components, you might also want to remove the catalytic
converter and install a new Oxygen sensor (the Bosch "universal" 3-wire type works fine) . In
theory, this can be done with the cat' still installed on the car, but it will take the special Alfa
wrench and a lot of horsepower to accomplish this task. Removing the cat' is no bargain either
however, and may require cutting the four rusted bolts which attach the converter unit to the header
pipes. Replacement with stainless steel bolts and a new gasket is HIGHLY recommended and will
make this a much easier task in the future. Installation of the new Oxygen sensor dramatically
dropped my CO emissions from .44% to .01%, and HC output from 99 ppm to 3 ppm. The motor
now runs smoother and gets increased gas mileage as well.
Installation of the new exhaust is very easily accomplished by hanging each unit in place (new
rubber hangers may be in order), and then bolting everything together. Again, new stainless steel
bolts and fresh gaskets are nearly essential here, and can be supplied by Stebro.
Those of you with off-road racing aspirations for your 164 may be interested to know that Stebro
also makes a cat'-bypass unit (with O2 sensor socket), which can be installed in place of the
catalytic converter. This should bring your 164 closer to Euro performance spec's and lower the
operating temperature a bit, but is legal only for off-road use.
Now that we've enabled the V6 to exhale more efficiently, it's time to work on the intake. If you
look in most any car magazine today, you can find about a zillion different conical intake filters
"available for most cars", which replace the stock air-box and filter. As is usually the case, "most"
rarely includes the Alfa Romeo 164. Fortunately however, after a few conversations, measurements,
pictures, etc., it was determined that MSDS could custom fabricate an adapter which would allow
fitment of one of their high-flow "Clean Air Act" 5" conical filters.
Upon receiving the MSDS filter, I quickly ran out to my 164, opened the hood, and proceeded to un-bolt the air-box and filter. Fifteen minutes later I realized I had a problem - the factory air-box also
serves the function of supporting the air meter which it connects to. Once again, some custom
fabrication would be required - this time, my Dad came to the rescue and was able to compound
bend some sheet metal into a supporting bracket which bolted into the holes from the (vacated) air-box and support the air meter. This time, fifteen minutes later I had a new filter installed.
It would be nice if I could invest all the money I've received from my fledgling automotive journalist career and rent some dynamometer time to test the effectiveness of this upgrade. But unfortunately, I haven't been able to find any free dyno' time yet! Hence, we'll have to rely on my "seat-of-the pants dyno", which tells me that there is a slight, but noticeable performance increase with these upgrades installed. Most of the improvement comes at the upper RPM range where the motor really needs to breath, but I've found there is a slight improvement throughout the complete rev' range. Frankly, the low, but not obtrusive, rumble of the exhaust, and the raspy note of the intake at wide-open throttle, alone make these upgrades worthwhile. Considering the modest increase in cost over stock replacements, I'd consider these upgrades a no-brainer for all but the most stringent of budgets.