164 Cat-Back Exhaust Replacement Like most things on Alfas, the stock exhaust systems are generally well-engineered, offering good fit and good flow characteristics. The exhaust on this 1994 164 LS Auto was no exception: it had performed well on the car but had developed serious rust-through. 
Stebro cat-back system installed on car
In selecting a replacement, the ability to stand up to salty winter conditions was of primary importance. For this reason, a Stebro stainless steel cat-back exhaust was selected over the original equipment replacement and various aftermarket offerings from companies such as Ansa, Supersprint, Remus, and Bosal. While the Stebro components were more expensive than OEM parts, they were in some cases cheaper than the other aftermarket exhausts which didn't offer the benefit of stainless construction. In this case, a cat-back system was selected, as the stock front pipe and catalytic converter were still in good shape, although Stebro also offers front pieces in several configurations.
The Stebro system showed excellent quality, with smooth bends and tight, neat welds. Composed of type 409 SS on the pipes and casings, and type 304 SS on the tips and flanges, the system should offer excellent corrosion resistance. The slightly larger tubing diameter (2.5", up from 2.25" on the stock system), and optional twin tip rear muffler (a 3" oval tip is also offered) hinted that a more sporty exhaust note and possibly more performance were hiding in this system.
Installation was simply a bolt-on job, requiring no bending or modifications to the exhaust. Stebro supplied a hardware kit, which included all necessary gaskets and stainless bolts and nuts. The only thing Stebro was not able to supply was new exhaust hangers, easily obtainable from many parts sources. The new exhaust used all of the stock attachment points, and fit quite well with a few small exceptions. The external size of the muffler boxes is somewhat larger than the original system, leaving very little clearance between the muffler and heat shields. The rear exhaust tips are also slightly off center. Bending the attachment points has helped, but not eliminated the centering problem.
Upon starting the car, a deep, bassy exhaust note was immediately evident. After warming the car up and checking for exhaust leaks, we took it for a test run. The exhaust was very pleasant, with a deep, aggressive howl upon hard acceleration, yet was only slightly louder than stock at cruising speeds.
The car also felt slightly more powerful, with greater torque throughout the rev range, especially evident in "off the line" pulling ability. Testing proved these seat of the pants observations, showing a gain of 0.675 seconds in the 0-60 mph sprint and 0.75 seconds and 3.3 mph in the 1/4 mile. Not surprisingly, testing initially showed an 11 bhp bump at the wheels, but when this was corrected for temperature the actual gain was 8.5 bhp.
Overall, the fit, finish, sound and performance gains make this an impressive system that should give many, many years of service due to it's stainless construction.
By the Numbers:
Stock Exhaust
| | STEBRO Exhaust
|
| Weight: 44 lbs | | Weight: 55 lbs |
Cost:
from Jon Norman's Alfaparts
Center: $127.60
Rear: $193.60 | | Cost:
from Stebro directly
Center: $199.00
Rear: $299.00 |
| 0-60 Accel: 10.12 s | | 0-60 Accel: 9.44 s |
1/4 Mile Accel:
17.66 s @ 87.4 mph | | 1/4 Mile Accel:
16.91 s @ 90.7 mph |
Wheel Horsepower:
159.5
| | Wheel Horsepower:
168
|
