I'm pretty sure he means the cat y-pipe from SHOsource.Yeah, running the duals will tend to make a deeper rumble. Just so you know, I don't currently use Magnaflows, you can get WickedFlows, which are not only cheaper, and smoother sounding (they make the car sound European, kinda like a Borla does), but are also better made.
That way you can make your return go farther and get the best sound possible.
Just a heads up though, running the duals with 2.25" mufflers may make the car drone.
Based on the $600 price difference between the SHOsource y-pipe and the Magnaflow direct-fit cat replacement on their site, I'd hazard a guess to say they're different. Plus, on Magnaflow's website, they don't specify anywhere that their direct-fit model is high-flow. Not to argue your point that their high-flow models are a gimmick, but it wasn't advertised as a performance upgrade. And based on how gorgeous the other y-pipes are on SHOsource, I think our G4 vulcan pipe would be a touch better than what you've posted.Ok, yes, I missed that, I only saw the picture at the top which was showing the older design. They do not show an actual picture of the Magnaflow part, but I did find one elsewhere. If you look at the Magnaflow brand part, it is downright appalling.
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This is what Magnaflows Gen4 part looks like. Notice how the rear cat (the round one) is small and look at the shape of the whole thing. First off, in the confines of the original design, there is not much you can do in the way of performance. Not only is Magnaflow using the same 400 cpi catalyst, by opting to use a round catalyst, they are actually making it smaller than the stock one and also smaller than the one in the link I posted above. That is bad for airflow, sound, and overall performance. Just so you can visually compare, here is the image from the above link.
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My recommendation, leave the stock one in place. You could however get more sound by getting rid of the third cat, which is not monitored by the OBD-II system and will not trigger a CEL.
It turns out there is a high performance cat for the Gen 4 Vulcan, please see this page.
Item Details
That makes me a sad panda.Ok, if you pull the stock one aprat, it uses a stamped y-connection that improves flow and reduces turbulence. The Magnaflow design lacks this detail, they just joint two pipes together. Because of the way the pipe joins, this creates backpressure on one bank. Without the special stamped piece, the Maynaflow y-pipe is inferior to the stock one.
On the Bank#1 cat being smaller, here are the actual numbers. The stock cat and the one I posted above use a 3" x 5" oval substrate, which has a cross sectional area of 17.99 square inches with a 400 cpi ceramic substrate. The Magnaflow with its round body is just 4" round diameter also 400 cpi ceramic gives you a cross sectional area of 12.56". That means the OEM and the Bear River converter flow 30% better on the #1 bank than the smaller Magnaflow unit.
The Bear River high performance unit flows 50% better than the regular unit with its 200 cpi metallic substrate. It otherwise has the same cross section as the regular units, its the lower cell density that makes the difference.
On the price difference, the part numbers on SHO source and the Magnaflow website are the same. Magnaflow does not make a separate high performance line, all their direct fits are ordinary 400 cpi ceramic. In fact a simple fact that proves that the Magnaflow is in fact the normal part is the fact that one converter is an oval body. Magnaflow does not make high flow oval bodies, only round. The price shown on the Magnaflow site is the suggested installed price, i.e. the price of their converter assembly installed on a vehicle. You cannot buy directly from Magnaflow unless you are a distributor, and Magnaflow is not about to post prices that would undercut their distributors, who are free to sell stuff at whatever price they wish.