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The industry standard
During our discussion of the initial test results, we were given a number of explanations, ranging from "You guys are just idiots" to "Those numbers don't matter if they aren't on a Dynojet." We have to admit that the Dynojet legacy has become somewhat of a self-fulfilling prophecy. In the early stages of our industry, the Dynojet was the least expensive way to get repeatable results; it was subsequently used by many as a "standard" by which all other dynos were measured. The more the industry quoted it, the more it became a number to quote. We didn't want to continue the circular argument of which dyno was right or wrong (see our "D'You Know Your Dyno" story in Issue 08) and with our deadline fast approaching, it was discouraging that almost everyone asked failed to respond to our requests for an interpretation of the results (or simply responded that we were idiots, without any additional edification.) In the end, we resigned ourselves to retesting the headers on an available Dynojet that was "accepted" by our peers, simply to corroborate the graphs with those acquired from the Dyno Dynamics dynamometer. So, off we went to AEBS in Miramar, Calif. to hold another, one-day, header shootout. Only by this time, 5Zigen had required us to return their sample header, so we were one header short. Also, we knew that the car was now in alignment and that all headers re-tested would be done so without the power steering and air conditioning belts running off the engine; this was sure to have some effect on power production. Our industry peers agreed upon a rough estimate of +3 to +5 change in power freed up by the removal of the units and the belts that drove them.

ON TO THE SECOND TEST
Again, we tested the headers in a random order (although we must admit that getting the HyTech test out of the way first eased a lot of tensions - sort of) under the watchful eye of the techs at AEBS who, as a matter of disclosure, didn't have a participating header in the test and who don't (to our knowledge) have authorized distributor agreements with any of the manufacturers listed. Also, the graphs shown are the median from the runs conducted on each header as compared to the median baseline reading found. (To extract the median run, we first insured that all the power curves were overlapped to within 1hp, then picked the graph showing the median peak power gain.)

BASELINE - TEST SET 02
This is noteworthy because the baseline power rating achieved on the Dyno Dynamics dyno is almost 15% percent lower than the rating we achieved on the Dynojet. We note this only because, mathematically speaking, if both dynos are accurately measuring power gains then the percentage gain (or loss) at any particular RPM point should be relatively close between both graphs.

HyTech - Test Set 02
This time around, the HyTech unit made about 3-5 additional horsepower between 3400-4300rpm, then slowly produced more power over stock from about 6300rpm to redline. In all other areas of the graph, the power gain was negligible. Peak power production rose from 160.4hp to 168.5hp.

Spoon - Test Set 02
The Spoon header made the powerband react much in the same way as the HyTech; a small increase around 4000rpm, followed by negligible gains until 6000rpm, where it produced an increasing amount of power all the way through redline. No other area under the curve was affected significantly, and the peak power rating rose 5.7hp to top off at 166.1hp.

Greddy - TEST SET 02
Greddy's offering also showed little to no change under the curve, with the exception of a small dip (1-2hp) between 5000-6000rpm. The entire powerband seems to have stayed the same with the exception of the increase of maximum horsepower, topping the graph out at for an increase of 2.9hp. peak horsepower, raising the maximum rating to 163.3hp.

WeaponR - TEST SET 02
From the start of the sample to the VTEC actuation point around 5600rpm, the WeaponR powerband remained unchanged from the baseline. At VTEC actuation, there was a 2-3 hp loss that steadily decreased until about 6500rpm. From there, the WeaponR unit made increasingly more power until it's peak rating at 164.9hp.

DC Sports : 4-2-1 - TEST SET 02
The first of the DC units showed negligible change to the power curve until about 7000rpm. From there until redline, the unit managed an additional 2-3hp over the baseline, ending with a 163.9hp max rating.

DC Sports : 4-1 - TEST SET 02
The DC 4-1 unit showed negligible changes from the start of the sample until about 4800rpm. There, a slight dip occured (but we should note that it was only evident on this median graph; other graphs showed an essential overlay from the baseline run.) Just after VTEC, the power curve dipped slightly and then picked up from about 6700rpm to redline, for a final peak horsepower gain of 4.6hp.

SO WHICH IS THE ULTIMATE HEADER?
Well, that's hard to say. "Ultimate" as we mentioned before, is relative to exactly where and how you're going to use the product. It is a peak horsepower industry that we live in; at least, it's a peak power industry that has been marketed to you - the consumer - for well over a decade now. And while increasing peak horsepower numbers is a sure sign that something is happening when you bolt on your new header or aftermarket part, it's not necessarily the best thing to happen. Take the DC Sports 4-2-1 header, for example. In both test sets - Test 01 and Test 02 - this particular header wasn't the maximum horsepower producer. It did, however, display a sizeable amount of low-end power in one test and a decent gain in another test. Does that make DC Sports the loser? We think not. Of all the headers tested, the DC headers counted for two of the three tested that had CARB approval. That may seem unimportant right now, but it sure will make a world of difference when your car comes up for mandatory emissions testing and you no longer have access to your stock piece. It takes a great deal of engineering, testing, and re-testing to gain CARB approval AND still make usable horsepower and of all the headers tested, DC Sports was the only one up to that task. On the other hand, a full-race engine builder could care less about CARB approval and may be willing to sacrifice some parts for others in the search for the header that best compliments his/her setup. The power steering pump and air conditioning compressor, among other things, are some of the first things to go in cases like this. So, with all the graphs and numbers and interpretations, what exactly did we learn about our headers?

WHERE DO WE GO FROM HERE?
We're convinced that we've proven something, but it's not directly related to which header fared best in our tests. Essentially, what we uncovered is a complete and utter lack of a certifiable standard in the industry. It's not a battle of which dyno manfucturer makes the best product (and therefore which parts manufacturer can make "honest" horsepower claims.) It's actually a call to arms for our industry, as a whole, to establish a set of rules, procedures, and equipment from which we can all extrapolate meaningful data about the condition of our engines and the benefit of the modifications we are making to them. Independent groups like the Society of Automotive Engineers have already established a system like this; our industry needs to whole-heartedly adopt those standards, or put its collective minds together to establish our own so that, once and for all, any one of us can say, "My car made X horsepower from Y modification," without having to qualify it with excuses about altitude, temperature, and the brand of dynamometer used.

BUT JUST TELL ME - WHO WON?
Aside from the revelations we had about "standardized" testing procedures, we also amassed a mountain of data. And, in our current "peak horsepower" world, if a winner was to be chosen from that data by maximum peak horsepower gain alone, the winner in both test sets - as clearly identified by the graphs - is HyTech Exhaust. We welcome and look forward to your comments and suggestions.

*DISCLOSURES
Many of our pundits were quick to point out that the Dyno Dynamics dynamometer used for the first set of tests was not considered an "industry standard" piece, simply because its presence is outnumbered here in the States by other dyno manufacturers. However, we would like to point out that other tests conducted on the Dyno Dynamics dyno during the same time frame show baseline and power gain numbers that are consistent with the Dynojet numbers quoted by the manufacturers of those particular products. Additionally, our test of a particular part (documented in this issue) on the Dyno Dynamics unit mirror the power production numbers shown by the same part on a similar platform, as tested on a Dynojet by our sister publication, DSport. So, for our detractors, we say - if a wooden yardstick is three feet long, then a steel yardstick should be, too.

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