Will it Survive?I have an '03 Mustang GT with a 70mm throttle body, a cold-air kit, and an aftermarket exhaust system with an X-shape crossover. The car currently has 60,000 miles, and I'm thinking about installing a supercharger or a turbo kit. I'm worried about the stock short-block and the mileage. Will the engine last? If not, do you have any other ideas?Rich GatesVia the Internet
In general, a basic bolt-on super-charger or turbo system would be a fine upgrade to your car. Whatever you do, the power-output levels are what you need to be concerned about.
Throughout the years, knowledge gained by supercharging 4.6L Two-Valve Mustangs with stock engines has resulted in some general rules of thumb in terms of what will stay together at various power points. Furthermore, these levels have been impressive given that these cars have relatively weak cast hypereutectic pistons and powder-metal connecting rods. I'd say that you can figure on safely making about 350 rwhp in your car as long as the tune is good. That's more than 400 at the flywheel, so you'd have a fun ride for sure.
Most supercharger systems will get you into that range with 6-8 psi of boost. With an intercooler, expect 25-30 hp more with another 1 or 2 pounds of boost. Start being careful with your car at around the 400-rwhp mark, which is approaching 450 at the flywheel. A good shop with access to a chassis dyno and the knowledge to do a spot-on electronic tune will get you in the range of 400 rwhp or more, but you'll still need to be careful. I've heard of stock '99-'04 Two-Valves that make staggering amounts of power into the 500-rwhp range, but they generally don't hold together for any length of time.
It also depends on how you drive the car. Beat on a supercharged, 350hp 4.6L Two-Valve Mustang every day, and the engine probably won't last as long as one in another car that makes 450 hp and is treated more gently. The mileage on your car shouldn't be a problem as long it's been regularly maintained and hasn't been driven really hard during the 60,000-mile span.
Four-Eyed Fox with No FogsSeveral years ago, my wife and I purchased a late-year '83 GT from its original owners. The car was stock down to the last detail with 40,000 miles. The previous owners claimed they hadn't made any modifications to it. In the Dec. '06 issue, the article "Installing GT Foglights" claimed all '82-'04 Mustang GTs had foglamps in the lower front valance.
We've owned other GTs from that era and this was the only one that lacked foglights, so for the most part, it would seem that statement is true. I would've investigated it further at the time had I thought it was unusual. I would've also sent a picture to accompany this letter but I am currently deployed overseas. I have yet to see another GT from that era without foglights.Kyle KoeperKuwait
Thank you for the information and your service to our country. We hope all Mustang enthusiasts stationed overseas, as well as everyone else, return home safely.
It's interesting that your car doesn't have foglights and the original owners claimed to have never removed them. I guess it goes to show that production anomalies on Mustangs have always been a part of the car's lore in some form or another. We'd be interested in hearing from owners of other square-light Fox 5.0 GTs without foglights.
Legal Eagle '06I recently purchased an '06 Mustang GT and want to add a few performance parts, such as an exhaust, a cold-air intake, and maybe a throttle body and an electronic tune, but I'm afraid of two things. The first thing is voiding the warranty and the second is passing smog. Do you know of any manufacturers that make smog-legal performance parts for California that won't void the warranty?Steve GillespieSacramento, CA
Any cold-air kit for a new Mustang will be emissions-legal in all 50 states. They have to be, so you should be okay there. The same goes for throttle bodies and most exhaust systems. These days, a good majority of the aftermarket manufacturers make sure the components are emissions-legal for a car as popular as the new Mustang.
Warranty issues depend on the dealership and your relationship with them. In general, minor bolt-on items such as cold-air kits and throttle bodies shouldn't be much trouble. I can't speak for other states, but as far as California goes, you don't have to get a new-car emissions tested for five years, so that's another perk in your favor. In any case, keeping the car legal isn't difficult. You can check with the various manufacturers on whether a given piece is legal or not.
Window-Seal Retrofit?I'm hoping you might have an answer to a question I have regarding the '94 GT coupe I've owned since new. When doors are opened and closed on the new Mustangs, the windows automatically lower and raise slightly to form a better seal around the weatherstrip. Is there any way to retrofit my '94 with this feature? Due to security and weather concerns, I can't always keep the window cracked. When it's rolled up all the way, the window smacks against the metal clip that holds the weatherstripping in place. When it rains or during car washes, it leaks unless I lower and raise the window, which I can only do while in the car. I would love to have the feature retrofitted to my '94.Scott BingenheimerBrookfield, WI
My thought is that it will be difficult to perform this retrofit since the new car is completely different than the SN-95 Mustangs. If the last '04 SN-95s had this feature, it would be easier to add it to earlier cars.
The bottom line is that adding body-oriented updates to cars that are of a different generation are harder than if they're of the same general design, such as '94-'04s. The way you're doing it-manually, as it were-seems to be a good method to employ, so I'd stick with that. If anyone knows how to do this conversion, please let me know and I'll pass along the knowledge in this column.
As far as the clip that holds the weather-strip in place, it shouldn't come in contact with the glass. Something's out of place there. The clip might need to be moved or bent out of the way. Maybe your door is out of adjustment, causing the glass to come in contact with the clip when you close it. Whatever it is, there should be a relatively easy fix.
Send your '79-'07 Mustang questions to: Late-Model Corral, 9036 Brittany Way, Tampa, FL 33619, or e-mail mustang.monthly@ primedia.com.