This seems to be a hot topic at the moment (in more ways than one), so here's a list of the primary performance y-pipe design and fabrication features, the ones that make real differences in power output and durability. Different y-pipes may appear to be similar on the outside, and may or may not fit on the car equally well, but there are a lot of details that add up to make the most effective product. There's no better example of that than the superior results we've gotten with our new 02/03 y-pipe for the VQ35DE.

Materials: No question that 304 stainless tubing is best, not just for corrosion resistance, but for its superior thermal containment (sustains exhaust velocity because its not cooling off, which means more power, and limits heat transfer into the engine compartment), tensile strength (resistance to cracking) and suitability for TIG welding (much stronger than MIG welding - the difference between melting the parts together and "gluing" them).

Welding: For strength and long term durability, TIG welding is vastly superior to MIG welding and is the only appropriate way to weld stainless steel. It also avoid the intrusion of welding materials into the interior of the pipe (can cause a lot of power-robbing turbulance), which is difficult to avoid with MIG welding.

Flex Sections: The weakest link in any y-pipe, its important that the flex section be lined to avoid hissing noises, and durably made to avoid leakage or interior collapse (some will remember that this happened to us with a HUGE batch of bad flexes almost 4 years ago - what a nightmare). Also very important that the flex section be long enough for adequate flexibility, and that the inside diameter is the same as the tubing sections it connects. I've seen other brands where that inner flex diameter is smaller than the tubing and that bottleneck is unnecessary. The flexes we use cost 2-3x as much as the cheaper components used on some y-pipes.

2-1 Collector design: This has a direct effect on power. Cattman 2-1 collectors are different from all others I'm aware of - they are true merge collectors, where the two merging primary tubes are cut up the sides and gradually come together at about 15 degree angle, welded on the inside and out. This design minimizes turbulence and reduces back pressure. Other brands use a "swaged" merge, where the ends two primaries are cut off square and welded directly to a receiving pipe that has been stretched (swaged) into an oval. Instead of the two exhaust streams coming together smoothly, its basically a train wreck that results in excess turbulence, back pressure and loss of exhaust velocity.

Proper tubing diameter: Bigger is not always better, and we have always found over the years that a 2.25" diameter tube at the end of the y-pipe (particularly if its feeding into a 2.5" catback exhaust) is more effective on normally-aspirated cars than larger diameters. You have to keep that exhaust flowing, especially that close to the engine, to maintain power-enhancing exhaust velocity down the rest of the exhaust.

All of these features make a positive difference in the power output and durability of Cattman y-pipes, and each one adds to our production costs and that's why the CP y-pipes are a little more expensive. You're not paying more for a name or feeding us outrageous profits (I wish) - you're clearly getting a better product in return.

Obviously we could make a cheaper y-pipe - there's certainly a market for one - but that's not our operating philosophy. We get far more satisfaction from creating and selling the best products available rather than selling the most or bragging about our little exhaust empires.

BTW, our y-pipe sale (on the group deal forum) ends tomorrow (Monday, 7 June). Regularly priced at $350, they've been on a 2-week sale at $285, which is an outstanding value for those who see value in the features I describe above. Just call our order line at 800.759.9920, betweeen 8-5 MST. More specials will follow.

Brian C Catts
Cattman Performance