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how do they compare?
Conical Merge Collectors & Welded Merge Collector

We are often asked how well our Conical Merge Collectors perform on the dyno against traditional, and much more expensive, welded merge collectors. Many of our long-time customers have done extensive dyno testing that showed they performed very well but we didn’t have hard data to share. Now we do!

Verified proformance in Collectors

We were approached by a long-time customer that planned to use a set of our collectors for a header they were designing for a new customer. Their customer wanted to use a welded merge and wasn’t too concerned about cost just plain performance. But isn’t that what we all say until they get the bill? We were requested to prepare a collector kit that would be comparable to the welded merge collectors he was given in order to conduct a direct dyno comparison. His customer just couldn’t believe that our $50 collector would perform as well as a $350 collector!

In fairness, there are some differences in the collectors that should be disclosed. First, their collector was finished and ready to bolt on. Ours was a kit that required some assembly. It takes about two hours to assemble and weld a pair of collectors to the header. Slip-on collectors do take slightly longer to build. And you will need to have some basic fabrication tools such as a TIG or MIG welder, a hand grinder and a saw, preferably a metal cutting bandsaw.

How to build a Megs Conical Merge Collector, click here >> Collector Assembly Guide

Compared Collector Results

The two different collectors would have to be as similar as possible in dimensions for the results to be comparable. If the collectors differed in this regard it would call into question the results and defeat the purpose of the test. In addition, the unique nature of the test engine also required some slight customization of each collector.

Neither we nor the builder of the welded merge collectors set the collector specifications; these were all set by the customer. This individual has been building high-performance and race exhausts for many years. On this project he was working with a major aftermarket automotive company.

The test engine is a 482 cubic inch big block Ford V8 with a 4.25” stroke and 4.25” bore. In earlier tests it generated around 550 horsepower. The base collector they selected would use 2” primary inlets and a 3.50” diameter outlet. This would be matched up to a 3.50” x 4.50” x 8.25” length (7 degree) transition cone.

The welded merge collector that our competitor supplied was a very beautiful part. The welding was top-notch and even the inside of the collector had a fantastic polished finish! It was going to be tough to compete against something like this, but we had to know once and for all how we stacked up!

We supplied our customer a collector kit that included (2) 2” 4-into-1 304 Stainless Steel collectors, (8) matching bullet vanes and the fixture tool to assemble the merge bullets. Also included were a set of transition cones as previously described. Our customer then assembled everything, adding additional tubing to fabricate it as a slip-fit collector. Similar to the welded merge collector, we generally recommend blending and polishing the bullet assembly for optimum performance. However in this case, they were left unfinished.

Now came the moment of truth, back-to-back dyno pull using the same set of headers….

As you can see from the chart above, the results were amazingly similar! At certain RPM’s there are differences. Generally, the Megs collector produced more HP and Torque up to about 5200 RPM. The competitor pulled slightly more from 5200 to 6000. When you consider the RPM that most street-driven vehicles operate at, the results were astounding! Compare the prices and it could be hard to justify spending several hundred dollars for gains seen only in the upper reaches of usability! Now if you are building a full-bore money-is-no-object racecar, you might be able to make an argument. And if he had just polished those bullets…

Consider your needs and you make the call!




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