Mustang MonthlyHow To Tech Qa
2002 Mustang GT Convertible & Mustang Contest - Late-Model Corral
Miles Cook Answers Your '79-'03 Tech Questions
Mufflers on the CheapI'm looking for low-buck performance mods for my '02 GT convertible, mainly because my wife doesn't think Mustang parts are as important as groceries. I have also recently discovered the joys of shopping on eBay. I found an '01 Cobra stock exhaust system for less than $100.
Wouldn't the Cobra mufflers be an improvement for my '02 GT? Could you recommend an aftermarket muffler that improves performance but is also reasonably quiet?Mark BartonLucedale, MS
A used aftermarket exhaust system would be a better bet than the Cobra mufflers. It's never been tested, but I would guess the Cobra mufflers wouldn't really allow the engine to make any more power than what's on the car now.
Recommending an aftermarket after-cat (behind the catalytic converters) exhaust system is tough to do since the systems sound different from one another. It's a subjective issue that's best decided by hearing various systems on Mustangs so-equipped. All of them should help make a measurable difference in power output (usually in the 10-15hp range), and most fit pretty well and can be considered a bolt-on upgrade. You have to decide which one you like based on sound. There are probably a dozen or more manufacturers that make systems for late-model Mustangs. Examples include Bassani, Borla, DynoMax, Flowmaster, Hooker, JBA, MagnaFlow, SLP, Spintech, and certainly others.
Check company Web sites and shop around (eBay is a good source for used parts as are many Mustang Web sites such as www.corral.net and www.stangnet.com.
Also consider other low-buck options such as cold-air kits, a set of 3.55 or 3.73 rearend gears, and that ultimate bang-for-the-buck standby: nitrous. Both NOS and Edelbrock offer good-quality nitrous systems for your car that, when tuned right, work quite well in safely offering 100 or more horsepower.
Gear Ratio RationaleIn your Jan. '04 issue, a reader asked about the gear ratio in his '97 GT. You stated you didn't know of any optional ratio on '96-'03 two-valve engines. My two-valve '96 GT came with an "optional ratio axle," as clearly marked on the window sticker. This engine turns about 200 rpm faster than my '89 LX 5.0 (which I still have and can make direct comparisons) at around 65 mph. My assumption had been the '89 had a 3.08, so the '96 must have a 3.27. Now I'm wondering if my '96's option is the 3.08, which would make the LX ratio a 2.73. Maybe I was able to answer the question if there was an optional ratio.John McIlnayDunlap, IL
The window sticker you sent clearly shows the optional gear ratio listed in the fourth line from the bottom under "optional equipment" on the right side of the sticker. Thanks to your input, I realized I wasn't fully informed about this subject when I replied to Scott Sauter in my January column. Turns out there was an optional ratio for all '94-'98 5.0 and 4.6 GTs. According to the Mustang Red Book by Peter Sessler, the standard ratio for your car was 2.73 and the optional ratio was 3.27.
You didn't say whether your Fox-body is a five-speed or an automatic (which could make a difference in axle ratios and how the car is equipped), but it would seem your original assumptions are correct. If the '96 has the 3.27 and the '89's engine turns a little slower at speed, then it likely has a 3.08. If it were a 2.73, the difference between the two cars would be more than 200 rpm at highway speeds; it would be in the 300-400-rpm range.
When I said I had never heard of an optional ratio, I was speaking of the '99 and newer cars; that is, square-edge Mustangs. Including the earlier round-body cars was incorrect. But for the '99-'04s, I'm certain all of them have a 3.27 ratio. That includes V-6, GT, and Cobra models, both automatics and five-speeds. Starting with the '99s, optional axle ratios were dropped and the 3.27 became standard fare in Mustangs. The only exceptions, of course, are '03-'04 Mach 1s and Cobras, which are factory-equipped with 3.55s.