Somewhere I have seen a dyno comparison of a few of the brands from one of the car mags and it was only 2 to 4 HP. Most of them definitely sound faster though.
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2007 GT - Grabber Orange, exterior appearance package, IUP, leather, 5 Spd stick, 3.55s, C and L Street CAI, BamaChips tune, Gen 2 qtr window louvers, Astra Hammond chin spoiler, Mac Pro-Chamber with cats, Saleen Heritage Spoiler, FRPP LCAs,
For whatever its worth this months 5.0 mag had a bolt on dyno story, and Corsa Mufflers which claim to add 14hp added 1-5hp and 1-4 torque at various points throoughout the rpm range.
So not too much.
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2005 Ford Mustang GT Torch Red Manual
Saleen Supercharger 3.4 pulley/Brenspeed Tune
FRPP Stingers Axleback Muffler System
CHE Lower Control Arms
Pro-5.0 Super Shifter
CDC Sequential Tail Lights
Best ET NA: 13.408 @ 105.31
Best SC: 12.6 @ 114 on Pirellis
Somewhere I have seen a dyno comparison of a few of the brands from one of the car mags and it was only 2 to 4 HP. Most of them definitely sound faster though.
That's within the run to run margin of error for a rear wheel dyno. The only way to accurately measure 4-5hp (about 1.5% of what is being tested) is to use a Eddy Current type engine dyno in a climate/conditions controlled dyno cell with every possible variable accounted for.
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Under Construction. Better, Stronger, Faster than it was before.
bottom line is... Theres some small improvement and u now sound like a beast... isnt that why u bought it? =P Its like buying a new stereo, you dont wonder about the added weight. U get it for the sound.
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USNA Class of '13
09 Dark Candy Apple Red GT (whipple HO S/C)
456 rwhp
436 ft/lb torque
2006 Mustang GT Horsepower ? 
