I recently completed a significant upgrade on my 02 Mustang GT Convertible. The car is a daily, year round driver and while I wanted better performance, reliability and streetability were also of paramount importance. As many of you know, I have another Mustang that’s oriented more toward the drag strip, and I didn’t want to turn my driver into a loud unreliable unlivable kind of vehicle. Consequently, I decided to go with a reasonably mild N/A build up with a target of making the GT at least as fun as a 97 Cobra that I used to have. To that end, I chose the following parts:
- Comp XE262AH cams
- Comp beehive modular springs
- Bassani mid-length headers
- Bassani X-pipe
- Accufab 75mm Throttle body
- Steeda underdrive pullies
- Fox Lake P-51 intake manifold
- Heads – Ported PI, Ferrea valves, milled .020”
- 3.73 Ford Racing Gears
The project went well, though it took a little more time than I had originally anticipated. The headers are a tight fit, but the Bassani mid lengths are decidedly easier to install than long tubes on the 4.6. The X-pipe did not fit out of the box and required a little trimming on the passenger side with a hacksaw, but finally bolted up ok. The intake fits but it does have minor hood clearance problems and getting the EGR system hooked up to it was more difficult than I expected it to be.
I ported the heads myself, and would say that they are generally an easier job than typical 5.0 heads since the ports are straighter and the castings are actually pretty nice. You do have to worry more about cleanup after the port work because of the oil passages in the heads which provide lubrication to the cams. I also installed the slightly larger Ferrea valves, Comp’s beehive springs, and had the heads milled .020”, which was the maximum amount recommended by Ford’s tech line to avoid cam timing problems.
I chose the Comp XE262AH cams because of their good power in the 3000-6000 RPM range, and their clean reputation for clearing stock pistons. Although there are several competitive cams out there that are popular for the mod motors, if you look closely at the specs you will find that Comp’s basic PI mod motor cams (XE262AH) are about as aggressive as the competitions stage 2 or even stage 3 cams. I’ve had great luck with Comp cams over the years, and these are no exception.
Following the upgrades, the street manners are good – very close to stock. While the car sounds more aggressive than it did stock, it’s not harsh or unlivable and in my opinion is just perfect for a daily driven cruiser.
From a power standpoint, the modifications created a much fatter power and torque curve in the 3000-6000 RPM range, gaining as much as 70 RWHP on the Mustang MD-600 dynamometer at 5900 RPM. I did not lose power or torque at any point in the curve, though I had expected to be slightly worse than stock below 3000 RPM. From a comparative standpoint, the car is much better than an intake/exhaust/pulleys/chip 97 Cobra that I tested recently, with between 20 and 25 more RWHP between 3500 and 5400 RPM, and as much as 30 ft-lb’s more torque in the same range. I also compared the car to a bolt on 03 Mach I that I tested and the modified GT compared very well, besting the Mach between 4500 and 5800 RPM. Final numbers on the GT were 262.3 RWHP and 279.1 RWTQ, which I estimate to be about 350 HP and 372 ft-lbs SAE Net.
Putting the dyno tests aside, the car feels great on the street, and is definitely more car than my old 97 Cobra was. Although I didn’t build it for the track, I think it might make for a fun evening one night next summer.
-Matthew
- Comp XE262AH cams
- Comp beehive modular springs
- Bassani mid-length headers
- Bassani X-pipe
- Accufab 75mm Throttle body
- Steeda underdrive pullies
- Fox Lake P-51 intake manifold
- Heads – Ported PI, Ferrea valves, milled .020”
- 3.73 Ford Racing Gears
The project went well, though it took a little more time than I had originally anticipated. The headers are a tight fit, but the Bassani mid lengths are decidedly easier to install than long tubes on the 4.6. The X-pipe did not fit out of the box and required a little trimming on the passenger side with a hacksaw, but finally bolted up ok. The intake fits but it does have minor hood clearance problems and getting the EGR system hooked up to it was more difficult than I expected it to be.
I ported the heads myself, and would say that they are generally an easier job than typical 5.0 heads since the ports are straighter and the castings are actually pretty nice. You do have to worry more about cleanup after the port work because of the oil passages in the heads which provide lubrication to the cams. I also installed the slightly larger Ferrea valves, Comp’s beehive springs, and had the heads milled .020”, which was the maximum amount recommended by Ford’s tech line to avoid cam timing problems.
I chose the Comp XE262AH cams because of their good power in the 3000-6000 RPM range, and their clean reputation for clearing stock pistons. Although there are several competitive cams out there that are popular for the mod motors, if you look closely at the specs you will find that Comp’s basic PI mod motor cams (XE262AH) are about as aggressive as the competitions stage 2 or even stage 3 cams. I’ve had great luck with Comp cams over the years, and these are no exception.
Following the upgrades, the street manners are good – very close to stock. While the car sounds more aggressive than it did stock, it’s not harsh or unlivable and in my opinion is just perfect for a daily driven cruiser.
From a power standpoint, the modifications created a much fatter power and torque curve in the 3000-6000 RPM range, gaining as much as 70 RWHP on the Mustang MD-600 dynamometer at 5900 RPM. I did not lose power or torque at any point in the curve, though I had expected to be slightly worse than stock below 3000 RPM. From a comparative standpoint, the car is much better than an intake/exhaust/pulleys/chip 97 Cobra that I tested recently, with between 20 and 25 more RWHP between 3500 and 5400 RPM, and as much as 30 ft-lb’s more torque in the same range. I also compared the car to a bolt on 03 Mach I that I tested and the modified GT compared very well, besting the Mach between 4500 and 5800 RPM. Final numbers on the GT were 262.3 RWHP and 279.1 RWTQ, which I estimate to be about 350 HP and 372 ft-lbs SAE Net.
Putting the dyno tests aside, the car feels great on the street, and is definitely more car than my old 97 Cobra was. Although I didn’t build it for the track, I think it might make for a fun evening one night next summer.
-Matthew
