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Originally Posted by marcussoori
Hi all. To understand my questions, check out this thread:
Stillen Headers on 370z
Now, here are my questions:
1) Doesn't the Stillen header look similar to the stock header, with similar diameter piping? What makes the Stillen one better? |
The major difference is that the stock tubes are not equal length, and the Stillen headers are. I'm really not an expert on these things, but my basic understanding of this issue is that equal-length headers ensure that the exhaust pulses flow into the single pipe (after the headers) in a steadily-timed train that tend to "suck" each other along, whereas with unequal length headers, you get "collisions" of exhaust pulses followed by empty-time where nothing is actively happening. There may be other differences that make it flow better that are more subtle, but I think the equal-length thing is the main factor. I'm sure someone from Stillen could chime in more on this.
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2) In the thread posted above, the installer says there is reduced midrange power, which could be helped with new Y-pipes. So, why don't we just get new Y-pipes rather than headers? How much more hp will I get with a new Y-pipe? Finally, are there any Y-pipe vendors?
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The Y-pipe / header issue is mostly conjecture at this point, but basically the stock cat-back exhaust (Y-pipe and everything behind it) is *really* restrictive. I installed headers and cats before I replaced it, and you could really hear how the exhaust was basically free-flowing up to that point and then getting all clogged up at the stock Y-pipe. It sounded very restricted.
Most people aren't going to buy a Y-pipe on its own, but rather a complete tuned cat-back exhaust system, which is the Y-pipe, the mufflers/tips, and everything in-between. You certainly can just buy that first (or only) and see some good gains out of it for minimal effort. I really wouldn't advise headers (or even cats, honestly) without also upgrading the rest of the stock exhaust.
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3) So, if I buy a Stillen exhaust, intakes, Berk HFCs, and a Y-pipe, won't I get close to the same hp gains as if I add the Stillen header?
Thanks in advance...
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Probably the intakes, HFCs, and exhaust (which includes the Y-pipe) add up to more gains than the headers alone by a long shot. Adding headers on top of all of that should take us even further though, and if you're going to install headers, you're going to have to remove your cats (and disconnect the Y-pipe if it's the stock cats) to do the install, so it makes a small amount of labor- (and gasket-) saving sense to install the headers before everything else, or at the same time.