KJ Jones
October 1, 2013
Photos By: KJ Jones

The automotive aftermarket's major trade shows are crucial for us. While the amount of under-one-roof Mustang hotness at these confabs can be a bit overwhelming, the good thing about walking the aisles of SEMA and PRI is that doing so affords us a preview of new gear.

BBK Performance showed off its latest exhaust innovation, Vari-Tune mufflers, at the 2011 SEMA show. Editor Turner gave us the initial heads-up about the new offering in his report on the show (“Vegas Jackpot,” Apr. '12), and a few days later, your author was on the phone with BBK, confirming a chance to bolt on a pair of the new cans.

Unlike standard, dual-chamber mufflers, Vari-Tunes feature an adjustable chamber valve that allows 'Stangbangers who desire a signature exhaust note to modify sound levels by as much as 8 decibels. Of course, how good the result of this mod sounds is extremely subjective. However, on the power side—and BBK's claim is that its axle-back Mustang system makes power—results are pretty definite. As we've stated countless times in the past, the dyno doesn't lie.

Our installation, dyno tests, and decibel tests were performed on the bone-stock '12 GT of Ozzie Meza by Ricardo Topete and Jose Serrano of GTR High Performance. Again, giving an opinion on how a Mustang exhaust sounds is largely a matter of personal preferences and taste. However, we believe the Vari-Tune after-cat system sounds great at all of the adjustment settings. And power gains—yes, there were gains—are quite impressive for a simple axle-back system. 5.0

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Sound & Steam

Baseline Closed Half Turn 1 Turn Open
RPM DB DB DB DB DB
Idle 69.70 80.40 82.40 83.94 86.50
2,000 87.30 103.30 103.86 106.30 108.30
4,000 92.50 102.80 104.30 107.50 109.60
6,000 110.00 110.40 112.80 112.40 115.60

Stock
Closed
Half Turn
1 Turn
Open
Difference
RPM Power Torque Power Torque Power Torque Power Torque Power Torque Power Torque
2,500 141.41 297.08 142.06 298.46 142.04 298.42 136.91 287.63 138.69 291.37 -2.72 -5.71
3,000 175.77 307.71 175.98 308.09 175.75 307.68 171.66 300.51 175.97 308.07 0.20 0.36
3,500 220.81 331.33 222.12 333.31 221.53 332.41 219.66 329.62 222.31 333.60 1.50 2.27
4,000 258.48 339.40 260.64 342.23 256.09 336.26 257.89 338.61 262.79 345.05 4.31 5.65
4,500 297.39 347.10 299.16 349.17 297.96 347.76 298.24 348.09 301.86 352.32 4.47 5.22
5,000 313.81 329.63 322.03 338.27 322.42 338.68 321.00 337.19 323.46 339.77 9.65 10.14
5,500 336.45 321.29 336.84 321.66 335.67 320.55 333.84 318.79 346.51 330.90 10.06 9.61
6,000 345.32 302.28 349.50 305.93 349.00 305.50 338.53 296.33 352.62 308.67 7.30 6.39