Tom Wilson
December 6, 2010

With that said, bolting on the BBK short-tubes showed they gave a substantial gain in torque below the torque peak, but at the midrange they lay down flat, before picking up 2 hp again around the horsepower peak. The dip is likely the engine management curtailing torque, but the short-tubes did worse than the long-tubes in the midrange, so there is something in the tube length as well.

A bigger, more established change came by adding BBK's X-shape crossover pipe to the end of the short-tube headers. This gave a gentle but definite lift up across the tach, but especially north of 3,500 rpm. The power peak reached 368 hp and 351 lb-ft of torque and in general the combination of short tubes, X-pipe seem to be worth 5 hp and 3 lb-ft over just the short-tubes in our test.

Photo Gallery

View Photo Gallery

The final test in conjunction with the short-tube headers was BBK's prototype cold-air intake. This was definitely a happy rpm addition, building power starting at 3,500 rpm, but with authority from 5,000 rpm to the power peak, where it added a solid 7 hp to the party. And, as you'd expect, it gave a big throaty roar in the process.

All told, the combination of short-tube headers, catalytic X-shape crossover, and cold-air inlet was worth just shy of 12 hp and about 8 lb-ft of torque at the peak compared to the stock baseline. Remember, too, that this is measured with the transmission in Fourth gear; the same tests in Fifth gear would add a horsepower or two, and an easy 10 lb-ft of torque.

Photo Gallery

View Photo Gallery

Stock*Short-tube*
RPMHPTQHPTQ
2,250111.67260.90116.52272.00
2,500127.90268.73134.41282.37
2,750143.53274.12149.29285.11
3,000162.92285.21167.67293.51
3,250182.84295.44185.59299.89
3,500210.01315.14208.73313.18
3,750231.28323.93231.66324.46
4,000253.51332.86253.24332.50
4,250282.93349.64278.89344.64
4,500291.48340.21297.78347.57
4,750302.06333.98306.60339.02
5,000320.76336.93322.58338.84
5,250335.45335.59338.24338.37
5,500340.25324.93344.22328.72
5,750343.79314.02349.04318.83
6,000352.20308.30352.95308.95
6,250362.22304.39360.06302.58
6,500358.71289.85364.72294.71
6,750350.66272.85360.46280.48

X-pipe*Cold-air*Difference
RPMHPTQHPTQHPTQ
2,250116.98273.05115.76270.224.099.32
2,500135.11283.84132.34278.014.449.28
2,750150.43287.28148.03282.704.508.58
3,000168.84295.57167.51293.234.598.02
3,250186.16300.83185.39299.592.554.15
3,500210.78316.27212.00318.101.992.96
3,750235.96330.48234.75328.773.474.84
4,000258.29339.12259.36340.555.857.69
4,250283.82350.70288.13356.065.206.42
4,500299.61349.69300.46350.708.9810.49
4,750308.87341.52311.56344.499.5010.51
5,000326.56343.02331.92348.6511.1611.72
5,250342.56342.69347.62347.7612.1712.17
5,500346.15330.56350.89335.0910.6410.16
5,750352.84322.30354.10323.4410.319.42
6,000357.97313.34365.29319.7613.0911.46
6,250364.15306.00374.66314.8512.4410.46
6,500368.48297.76376.35304.1017.6414.25
6,750285.96223.33368.86287.0218.2014.17

* These are dyno results from tests conducted on BBK's in-house Dynojet chassis dyno. All tests with short-tube headers were run in Fourth gear; those with long-tube headers were run in Fifth gear. Therefore, figures from the two test series should not be directly compared.