| Red__Zed |
01-18-2012 09:09 PM |
it is not terribly difficult to construct one though.
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So far, I have not seen anything to the contrary. Again, as the single turbo's only competitive edge is cost, anything other than the reuse of the stock exhaust manifold would work against that advantage.
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you are neglecting the efficiency opportunities afforded by a larger turbo.
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Until I am proved wrong, I'll stand by it. But unless someone can invent a reverse entropy device and defy the laws of physics, I'll be standing for a long time yet.
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I always laugh when people make statements like:
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A twin turbo system does these things extremely well and cannot be beat…even by a well engineered single turbo system. The single turbo system has too many compromises to make as effective of a street setup.
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and back them up with this:
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Until I am proved wrong, I'll stand by it. But unless someone can invent a reverse entropy device and defy the laws of physics, I'll be standing for a long time yet.
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rather than numbers. I understand you are running business, but isn't it good enough to just point at that there is nothing on the market that offers similar performance in a single, rather than broad, sweeping statements that cannot possibly be supported?
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On a V6? It would require a substantial amount of number crunching to find that crossover, but from some of the numbers that I have looked at, I suspect my original estimate of 1300+ may actually be conservative.
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Can you share the numbers you've looked at? I would love to see them.
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You know, just for giggles, I shot an e-mail to a contact I have at Garrett just to see if we can get the actual MOI numbers. In his estimation, a pair of GT2860RS turbos will have a very close total MOI when compared to a comparably sized single turbo (GT4094R). Remember that MOI is based on the square of the radius.
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I understand that, but you don't necessarily increase the MOI a lot to bump up flow. You wind up coming VERY close in terms of total MOI, and the efficiency of a single turbo can get things very interesting. Turbine clearance needs alone create a huge opportunity for gains in efficiency, not to mention the pulse density.
http://www.ztechz.net/sitebuildercon...t28rs_comp.jpg
http://www.srtforums.com/forums/atta...-map-ghost.jpg
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Furthermore, due to the loss of enthalpy from a longer exhaust pipe routing (required for a single turbo setup on a V6), the twins will be receiving more total enthalpy than the single and since their MOI's are so close already, the Twins will respond faster.
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At some point this becomes trivial relative to other gains (pulse efficiency, etc). Obviously systems like the STS don't effectively leverage it.
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That's a good question. It's been awhile since I looked at it. Keep in mind that the stock exhaust manifold has two ply heat shields as well. I'll see if I can dig up those calcs at home.
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I'd love to see them. I imagine the wrapped SS will be much better than you expect. |
