I've had my Flowmaster axle-backs on my 2005 5-speed GT for a week now. This is my first and, most likely, only mod for the car. Bought them for $299 at a local performance supplier and had them installed by a muffler shop I've used before, for a flat $50 fee. Here's my thoughts:
- Watching them take the factory exhaust off, it did NOT look like fun. Some of the factory bolts are hard to get to. The install of the Flowmasters was quick and painless by comparison. An amateur like me could do it, but I'm glad I paid. Make sure you shop around...Midas wanted $75 to do the install and a local performance tuner wanted **$175**. Also, if you plan to do it yourself, jack stands would help a lot.
- No noticable change in performance or gas mileage one way or the other. I did the battery unplug overnight at the supplier's recommendation. I called Flowmaster's tech support just to see what they'd say, and they claim their dyno tests show definite improvements in average and peak horsepower and torque over stock. Maybe. But if you buy axle-backs, do it for fun, not for extra pull.
- No shakes or rattles. No alignment problems. Plenty of clearance between the tips and the bodywork.
- The sound is great. It's MUCH different from the 40-series I had on my 2000. While that sounded harsher and more aggressive (in a good way), the new package is smoother and deeper.
- Oddly, the biggest and most enjoyable difference is in regular driving, just working up and down through the gears. You get a nice growl, especially during idle-down. WOT is not THAT much louder than stock, inside the car. From outside the car (had my wife get on it a couple of times, including driving away), the sound is notably deeper and louder than stock, but not drastically. It'll turn the heads of Mustang fans, but won't grab everyone's attention.
- I've had no resonance at all. By this, I mean I've had no vibrations from any part of the car synchronous with the exhaust note. However, if you're in 5th and step on the pedal at say, 45 or 50, there is a good amount of drone until you hit 60 or so. You can cruise at 45 or 50 in 5th with no drone, but if you accelerate without downshifting, it's definitely there.
- At highway speeds, there's a bit of exhaust note inside the car, and that's it.
- If you're looking for louder than stock, the Flowmasters are great. If you're looking for flat out LOUD, you'll probably be happier with the SLP Loudmouths or one of the other straight-pipe designs.
- Do I recommend this kit? Absolutely. The added sound volume and change in tone really ups the fun factor of driving, both around town and when you're on it.
- Watching them take the factory exhaust off, it did NOT look like fun. Some of the factory bolts are hard to get to. The install of the Flowmasters was quick and painless by comparison. An amateur like me could do it, but I'm glad I paid. Make sure you shop around...Midas wanted $75 to do the install and a local performance tuner wanted **$175**. Also, if you plan to do it yourself, jack stands would help a lot.
- No noticable change in performance or gas mileage one way or the other. I did the battery unplug overnight at the supplier's recommendation. I called Flowmaster's tech support just to see what they'd say, and they claim their dyno tests show definite improvements in average and peak horsepower and torque over stock. Maybe. But if you buy axle-backs, do it for fun, not for extra pull.
- No shakes or rattles. No alignment problems. Plenty of clearance between the tips and the bodywork.
- The sound is great. It's MUCH different from the 40-series I had on my 2000. While that sounded harsher and more aggressive (in a good way), the new package is smoother and deeper.
- Oddly, the biggest and most enjoyable difference is in regular driving, just working up and down through the gears. You get a nice growl, especially during idle-down. WOT is not THAT much louder than stock, inside the car. From outside the car (had my wife get on it a couple of times, including driving away), the sound is notably deeper and louder than stock, but not drastically. It'll turn the heads of Mustang fans, but won't grab everyone's attention.
- I've had no resonance at all. By this, I mean I've had no vibrations from any part of the car synchronous with the exhaust note. However, if you're in 5th and step on the pedal at say, 45 or 50, there is a good amount of drone until you hit 60 or so. You can cruise at 45 or 50 in 5th with no drone, but if you accelerate without downshifting, it's definitely there.
- At highway speeds, there's a bit of exhaust note inside the car, and that's it.
- If you're looking for louder than stock, the Flowmasters are great. If you're looking for flat out LOUD, you'll probably be happier with the SLP Loudmouths or one of the other straight-pipe designs.
- Do I recommend this kit? Absolutely. The added sound volume and change in tone really ups the fun factor of driving, both around town and when you're on it.