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l8r)
I am in the exact same boat as you.Originally Posted by Ludikraut
That is true, but since I'm looking to limit my application (road racing) to about 30psi, the topend isn't as critical as the spoolup. I'm trying to find a setup that will comfortably hold 30psi to about 8000 RPM and is able to spool to said 30 psi by 4000 RPM on a 2.0L. In looking at the 76 and 83 series, that goal seems to (of course) fall right between the two. It looks like the 76 would accommodate the spoolup, but may fall slightly short on the topend, whereas the 83 will easily do the topend, but probably spool slightly slower. So, once again, for results I wait. 
l8r)
Evolving Member
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Going from a standard EVO VIII turbo with inconel turbine and 9.8 cm/2 turbine housing, to the same turbo (TME) with TiAl turbine and 10.5 cm/2 turbine housing resulted in significantly faster transient response and better spool characteristics, despite the larger turbine housing. If one can fabricate a turbo with a compressor of at least the capability of an HTA3586, but with a turbine that enables it to outspool an HTA3582, then you have a winner where outright performance is concerned. The only remaining variable to be considered at that point (aide from fitment) is the cost difference.
^ thisOriginally Posted by Ted B
The compressor maps look nice (especially at higher PRs), but that doesn't mean much if the turbine side is the limiting factor, and that is my main focus. Where the EFR turbos are concerned, the turbines appear to provide increased efficiency vs. the (approximate) equivalent sized Garrett GT parts, and offer the added benefit of a 50% equivalent mass reduction as compared to inconel. Going from a standard EVO VIII turbo with inconel turbine and 9.8 cm/2 turbine housing, to the same turbo (TME) with TiAl turbine and 10.5 cm/2 turbine housing resulted in significantly faster transient response and better spool characteristics, despite the larger turbine housing. If one can fabricate a turbo with a compressor of at least the capability of an HTA3586, but with a turbine that enables it to outspool an HTA3582, then you have a winner where outright performance is concerned. The only remaining variable to be considered at that point (aide from fitment) is the cost difference.
HTA86 potential with better spool than a HTA3582 would be sick, I would buy one for my suby even if cost 2k
Evolved Member
Quote:

l8r)
Looking at the 76mm compressor map, I think it's what you are looking for. It will vary dependning on the exact VE of your setup at 8000 RPM, but just running some typical numbers, it looks like the compressor would be able to hold 30psi to 8000RPM on a 2.0L engine. Whether the rest of your setup will is another story.Originally Posted by Ludikraut
That is true, but since I'm looking to limit my application (road racing) to about 30psi, the topend isn't as critical as the spoolup. I'm trying to find a setup that will comfortably hold 30psi to about 8000 RPM and is able to spool to said 30 psi by 4000 RPM on a 2.0L. In looking at the 76 and 83 series, that goal seems to (of course) fall right between the two. It looks like the 76 would accommodate the spoolup, but may fall slightly short on the topend, whereas the 83 will easily do the topend, but probably spool slightly slower. So, once again, for results I wait. 
l8r)
Evolved Member
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HTA86 potential with better spool than a HTA3582 would be sick, I would buy one for my suby even if cost 2k
as far as i know, pricing is right around $2k.Originally Posted by juanmedina
^ thisHTA86 potential with better spool than a HTA3582 would be sick, I would buy one for my suby even if cost 2k
Evolved Member
as long as the 83/74 is good for 750+whp on my 2.2L and spools like a 35r ill be very happy.
Evolved Member
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Not terrible considering all the technology in the new BW turbos, BW's reputation for durability, and that a Precision 6765 billet ball bearing turbo costs about $1,600- $1,800.Originally Posted by n2oiroc
as far as i know, pricing is right around $2k.
Newbie
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I think the 7670 should be a great contender(not quite capable, but close) against the GT3582R for power and better than the GT3071R in spool/response. One of those...eating cake and having it too kind of deals. I really like those.
they are titanium alloys right?Originally Posted by R/TErnie
I don't know if anyone else is noticing but these are FORGED billet compressor wheels...not just billet compressor wheels. 
I think the 7670 should be a great contender(not quite capable, but close) against the GT3582R for power and better than the GT3071R in spool/response. One of those...eating cake and having it too kind of deals. I really like those.
Newbie
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I think the 7670 should be a great contender(not quite capable, but close) against the GT3582R for power and better than the GT3071R in spool/response. One of those...eating cake and having it too kind of deals. I really like those.
power-wise, how much behind the GT3582R would it be?Originally Posted by R/TErnie
I don't know if anyone else is noticing but these are FORGED billet compressor wheels...not just billet compressor wheels. 
I think the 7670 should be a great contender(not quite capable, but close) against the GT3582R for power and better than the GT3071R in spool/response. One of those...eating cake and having it too kind of deals. I really like those.
And how much better, spool/response than the GT3071R?
I know this is mostly speculations from analyzing the data, but it's a nice exercise.
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The compressor wheels are forged into billets.Originally Posted by SpecialNeeds
they are titanium alloys right?
This is done under extreme heat and pressure.
The heat and pressure cause the grains of the aluminum or what ever metal to form in tighter configurations and making a stronger billet.
Then the compressor wheels are machined to exacting dimensions.
Most anything that is machined from a single piece of metal is called a Billet.
Here's a brief history of how Billet Aluminum came about.
http://hubpages.com/hub/How-Billet-C...s-Are-Machined
The compressor wheels are forged billet, and the turbine wheels are Gamma Titanium, or Titanium Aluminide.
More than likely they are forged to near net shape and final machined.
These are also considered billet.
http://en.wikipedia.org/wiki/Titanium_aluminide.
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l8r)
At a pressure ratio of 3, or 30psi the 8374 is right in the most efficient island at roughly 53lbs//min.Originally Posted by Ludikraut
That is true, but since I'm looking to limit my application (road racing) to about 30psi, the topend isn't as critical as the spoolup. I'm trying to find a setup that will comfortably hold 30psi to about 8000 RPM and is able to spool to said 30 psi by 4000 RPM on a 2.0L. In looking at the 76 and 83 series, that goal seems to (of course) fall right between the two. It looks like the 76 would accommodate the spoolup, but may fall slightly short on the topend, whereas the 83 will easily do the topend, but probably spool slightly slower. So, once again, for results I wait. 
l8r)
At a pressure ratio of 3, the 7670 will have to be pushed off to approximately 70% efficiency to achieve 53lbs/min?
If these aren't ridiculously priced, the 1.05A/R T4 7670 will be what I choose.
Any pricing yet?
I heard around $2k?
Evolved Member
Just talked to raffi from full-race. Pricing may be out at the end of sema, but it could also be after thanksgiving. As soon as pricing is released i will be notified as i already have one ordered.
I strongly advise checking the dimensions for fitment before jumping into this head first. I suspect fitment will present rather serious issues in at least some cases.
Evolved Member
I haven't used my AC in years, I consider it expendable at this point. 
l8r)

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