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Old 06-13-2012, 04:44 AM   #21
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Quote:
Originally Posted by 18psi View Post
What cars have you driven with the 76 comp?
STi with a rotated 3076R. It spooled like a lightswitch. Far and away the least driveable turbo car I've ever experienced, and that includes a Supra powered by a GT3582R with a 1.06a/r T4 housing. The Supra still came on smoothly - the 30R STi had absolutely no power under 4200rpm, and then it felt like a dump truck rear-ended the car.

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I'm just trying to get an idea of what I'm working with so all input good or bad is welcome, don't hold back.
Y8s' curve isn't as bad as I was expecting, but the low boost at 3k also shows that the turbo is not going to respond nicely. Adding your T3 housing is going to make matters worse, since it's just going to increase the amount of airflow required to actually produce turbine pressure and get the turbo wound up.

If you think 200wtq at 4k is acceptable, then you'll probably be fine. I think that's utterly pathetic, which is why I don't think I would personally be able to tolerate a 2876R. My 2871R is as big a turbo as I would want on a street car, and TBQH I'm a little nervous about how the 0.92a/r twin-scroll EFR7064 I have on order for Theseus is going to act.
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Old 06-13-2012, 09:11 AM   #22
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Ok, I get it. You want maximum boost as early as possible. That's definitely understandeable. I guess that's where our tastes differ: I'm ok with low boost under 4k rpm to help gas mileage and basically "keep me out of trouble". Since any type of spirited driving is done well over 4k, good power is always just a downshift away. I'd take advantage of the low backpressure to really push the out of boost parts of the maps and compensate somewhat while still conserving fuel. Also it will be easier on the stock (for now) rods on such a high comp motor.

Thanks for everyone's feedback, I do appreciate it. Keep it coming by all means.

And Fae, maybe I will maybe I won't
All you need to know is you need to get your isht together and get your car back on the road hehe
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Old 06-13-2012, 12:13 PM   #23
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Quote:
Originally Posted by 18psi View Post
Ok, I get it. You want maximum boost as early as possible. That's definitely understandeable. I guess that's where our tastes differ: I'm ok with low boost under 4k rpm to help gas mileage and basically "keep me out of trouble". Since any type of spirited driving is done well over 4k, good power is always just a downshift away. I'd take advantage of the low backpressure to really push the out of boost parts of the maps and compensate somewhat while still conserving fuel. Also it will be easier on the stock (for now) rods on such a high comp motor.

Thanks for everyone's feedback, I do appreciate it. Keep it coming by all means.

And Fae, maybe I will maybe I won't
All you need to know is you need to get your isht together and get your car back on the road hehe

Yes I am going to pull my motor today.

Hey btw btw btw you have the 20G on your FXT still right? I have the 16g. My FXT out-lowends any turbo miata i've ever driven or gotten a ride in. Expect miata to feel slow unless you give it decent powah
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Old 06-13-2012, 12:18 PM   #24
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Yes, and I agree. The lowend is out of this world. But building the miata won't help lowend, so not sure where you're going with that. 250-350 will do the trick for me.
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Old 06-13-2012, 01:40 PM   #25
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Yes, and I agree. The lowend is out of this world. But building the miata won't help lowend, so not sure where you're going with that. 250-350 will do the trick for me.
Ya I am just saying that 250hp of miata power will seem slow as hell. I think you will need 400hp <3 to start approaching the feel of subiewoobie power.
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Old 06-14-2012, 09:37 AM   #26
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I'm hoping to end up with 350
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Old 06-14-2012, 11:26 AM   #27
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If 350HP is the real goal, then won't it be cheaper in the long run to just buy a new 2871R?

Multiple "cheap" turbos will eventually lead to one "expensive" turbo? I've bought a $300 churbo, and now have a $350 GT28RS. One more turbo and I could have just bought a 2871R. Just sayin......

Granted, I'm hoping to break 300HP, but if not, I'm done messing around. The 28RS is my stopping point.
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Old 06-14-2012, 11:31 AM   #28
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I'm hoping to end up with 350
It puts the 500hp in the car or it gets the hose


with e85 this is a no branner.
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Old 06-14-2012, 11:35 AM   #29
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See the thing is: I don't think I'll be dissatisfied with this. Like I said before, I ran a 3076 at super low boost and still liked the powerband. If this has even a little bit more torque under curve (and it def should), it will already be an improvement. I kinda prefer something that won't run 20+psi at like 3k because my poor stock rods will exit out the side REAL quick (and I don't plan to build block for at least another year, this one is practically new). And I want something that will keep building power til redline and not drop off, AT ALL. Otherwise I'd just pick up a tater or 2560 and run that sucker at like 18psi and have a plateu of torque from 3000-5500
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Old 06-14-2012, 12:14 PM   #30
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I think you can run the tater to 24psi, but I could be mistaken.
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Old 06-14-2012, 12:21 PM   #31
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Probably so, but dem has is as 19 and its already starting to nose over up top, so I'm guessing it will be very stressful on it without much gain over 20
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Old 06-14-2012, 10:07 PM   #32
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Originally Posted by 18psi View Post
Probably so, but dem has is as 19 and its already starting to nose over up top, so I'm guessing it will be very stressful on it without much gain over 20
What's his setup? I'm wondering how hard I should push mine?
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Old 06-14-2012, 10:25 PM   #33
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Quote:
Originally Posted by 18psi View Post
And I want something that will keep building power til redline and not drop off, AT ALL. Otherwise I'd just pick up a tater or 2560 and run that sucker at like 18psi and have a plateu of torque from 3000-5500
Then you want a 2871R with a 0.86a/r T25 housing.
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Old 06-15-2012, 12:51 AM   #34
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So they will both achieve this goal, but the 71 will hit boost/torque about 3-400 rpm sooner. Correct?

For giggles, here is my old 3076 boost log, when I was just starting to tune it, and with super duper low boost on an internal wastegate:



I HIGHLY doubt that this 2876 will spool slower, and that setup felt great IMO.
With how stupid short our gearing is, you're pretty much never low enough in the rev range for it to feel like a dog unless you're trying to drive it like a v8.
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2876 + t3 turbine housing = 29r ?-untitled.png  
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Old 06-15-2012, 03:16 AM   #35
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There should be a night and day difference in power/spool/everything between the log/china 3076 and the new hotness.
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Old 06-15-2012, 05:07 AM   #36
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Do it already and post results?
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Old 06-15-2012, 05:26 AM   #37
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Quote:
Originally Posted by 18psi View Post
And I want something that will keep building power til redline and not drop off, AT ALL. Otherwise I'd just pick up a tater or 2560 and run that sucker at like 18psi and have a plateu of torque from 3000-5500
Or just a 2560 with an intake manifold. Problem solved. And has spool.
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Old 06-15-2012, 09:12 AM   #38
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Quote:
Originally Posted by viperormiata View Post
There should be a night and day difference in power/spool/everything between the log/china 3076 and the new hotness.
Thats exactly what I'm thinking. Which is why I made this thread basically: to see if you guys agree.
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Originally Posted by elesjuan View Post
Do it already and post results?
In due time. I'm in no hurry.
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Or just a 2560 with an intake manifold. Problem solved. And has spool.
Yeah, no.
At 18psi that thing will be a lava pump past 5k
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Old 06-15-2012, 11:40 AM   #39
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500hp or bust

Log spools like nothing then instantly like hammer on ur puss

Tubular spools nice and smooth like wangoe in uranus

Log also has fail VE after a certain point.
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Old 06-15-2012, 12:15 PM   #40
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Quote:
Originally Posted by 18psi View Post
See the thing is: I don't think I'll be dissatisfied with this. Like I said before, I ran a 3076 at super low boost and still liked the powerband. If this has even a little bit more torque under curve (and it def should), it will already be an improvement. I kinda prefer something that won't run 20+psi at like 3k because my poor stock rods will exit out the side REAL quick (and I don't plan to build block for at least another year, this one is practically new). And I want something that will keep building power til redline and not drop off, AT ALL. Otherwise I'd just pick up a tater or 2560 and run that sucker at like 18psi and have a plateu of torque from 3000-5500
Quote:
Originally Posted by Savington View Post
Then you want a 2871R with a 0.86a/r T25 housing.
no

you want an intake manifold.

This is a 2560 with an intake manifold:



I still think the .64 is underrated. particularly by Sav and his crotchstroker Hustler.

ESPECIALLY in a street car.

my 2876 is fine in a street car. could i build boost sooner? sure. would I swap ends a block from my house? probably.

but I would not run some random T3 housing on it. I'd keep the .64 and run that.

Here is the photoshopped dyno curve of my car versus Turbo Tim's old twin setup. I simply took the curve 18psi posted above and joined the high left part with the high right part to synthetically illustrate the right VVT map.

I'm at 9 psi and Tim is at 15.




I have no doubt that a properly tuned built motor in my car would yield 250 whp before 4k at higher boost. But I'm not going to build it so someone else can buy the car from me and build it and show us.
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2876 + t3 turbine housing = 29r ?-paul.jpg   2876 + t3 turbine housing = 29r ?-twins_vs_2876.gif  
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