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Old 06-12-2012, 11:09 AM   #1
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Cool 2876 + t3 turbine housing = 29r ?

From Savs post in another thread:

Quote:
2876r is an oddball.......

Info below for reference:
2871R 52-trim:
Comp: 51.2ind,71.0exd
Turb: 53.9mm, 76trim, .86a/r, 21lb/min peak turbine flow

2876R:comp: 52.8ind, 76.1exd
turb: 53.9mm, 76trim, .86a/r 21lb/min PTB

3071R 56-trim (T25 turbine)
comp: 53.1ind,71.0exd
turb: 56.5mm, 84trim, .64a/r, 19lb/min ptb

3071R 56-trim (T3 turbine)
comp: 53.1ind, 71.0exd
turb: 60.0mm, 84trim, .63a/r, 20.5lb/min ptb
So I haz a Garrett gt2876r .64ar. I also haz an ATP .64ar T3 hotside which I'm told equates to a T2 .86ar. I am not afraid of lag, or having a 30r powerband, but I would like a bit better torque-under-curve with this setup (1.8vvt+etd long tube+this turbo) than with my previous setup (1.8 bp4w+begi log+china 3076r).

I know its kinda silly to ask "what would this unusual combination of turbo parts result in", but maybe we'll get a good discussion going. So here goes:

What would one expect the power/torque curves to look like on this setup? Spool? Response?
Assuming 3" all the way and EWG. stock motor (for now) so boost would be fairly low (again, just for now) and running e85.

Looking for feedback, not "omgz its gunna suck y0" or other pointless crap lol.
Thanks gents.
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Old 06-12-2012, 11:11 AM   #2
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do you acutally have a t3 turbine? or just the housing?
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Old 06-12-2012, 11:19 AM   #3
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ATP housing. Wheel will remain the same (so not quite 30r status, but...) with just larger ar

Sav was talking about how the larger compressor is pretty much useless since the t25 housing chokes up past 300 anyway, but I'm wondering if with the larger ar it wouldn't be so bad?

y8s graps look like his .64 comes on full boil 3600-4000 (4k being with vvt fully retarded) so I'm wondering if I should expect to be in the 4200 range or would it be worse? Also looks like he's building power all the way to redline, but he's only at 250, I'm wondering if mine should be able to hit 350 once I finally build the sb.
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Old 06-12-2012, 11:20 AM   #4
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it'll flow much better up top, way larger inlet. do it.
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Old 06-12-2012, 12:21 PM   #5
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Wink

So not completely failaidz then?








Any more feedback/input is appreciated.
I'm wondering how much slower (if much at all) it will spool.
Attached Thumbnails
2876 + t3 turbine housing = 29r ?-img_00281.jpg   2876 + t3 turbine housing = 29r ?-img_00282.jpg   2876 + t3 turbine housing = 29r ?-img_00283.jpg   2876 + t3 turbine housing = 29r ?-img_00284.jpg   2876 + t3 turbine housing = 29r ?-img_00285.jpg  

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Old 06-12-2012, 02:21 PM   #6
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y8s will be along shortly to describe in detail how shitty that turbo is.
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Old 06-12-2012, 02:22 PM   #7
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The 'GT28' part of the name indicates that you're using the smaller GT28 turbine wheel, which isn't the same as the GT30 turbine wheel, and won't flow as much. As far as the effect on final functionality, I doubt you'll be able to tell much difference from the driver's seat.
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Old 06-12-2012, 02:28 PM   #8
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Quote:
Originally Posted by Savington View Post
y8s will be along shortly to describe in detail how shitty that turbo is.

it acutally runs quite well on his machine.
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Old 06-12-2012, 03:46 PM   #9
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Quote:
Originally Posted by Savington View Post
y8s will be along shortly to describe in detail how shitty that turbo is.
His feedback, after running the turbo for basically ever, was very good.
My question for you: have you driven a 2876r car? Or are you going off purely posted measurements?

I mean he's making 250-60 or something like that at only 9psi with full boost well before 4k....That's really not bad at all in my opinion.

Quote:
Originally Posted by vehicular View Post
The 'GT28' part of the name indicates that you're using the smaller GT28 turbine wheel, which isn't the same as the GT30 turbine wheel, and won't flow as much. As far as the effect on final functionality, I doubt you'll be able to tell much difference from the driver's seat.
Correct, and I'm not trying to make a 30r, just a 28 that wouldn't choke up top. And by difference do you mean both in spool and final power output?
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Old 06-12-2012, 03:54 PM   #10
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In what world is 3psi at 3000rpm considered "good spool"?

https://www.miataturbo.net/showpost....26&postcount=2

Cueball makes 8psi at 3000rpm with a 0.86a/r 2860RS without the assistance of VVT:

https://www.miataturbo.net/showpost....4&postcount=44

76mm compressor = failaids

e: And you're talking about using an ATP T3 housing? That's only going to make things worse.

If I'm good for one thing, it's that I will never, ever tell you what you want to hear (unless it's true). Sorry

Last edited by Savington; 06-12-2012 at 04:05 PM.
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Old 06-12-2012, 04:04 PM   #11
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But his dyno plot doesn't look bad at all, at least when compared to others running much more boost
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Old 06-12-2012, 04:20 PM   #12
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Quote:
Originally Posted by 18psi View Post
But his dyno plot doesn't look bad at all, at least when compared to others running much more boost
Post his plot, I can't find it.
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Old 06-12-2012, 05:08 PM   #13
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The only one I can pull up at work (damn pic filter) when he was playing with different vvt settings iirc



I'll look for more when I get home.

*edit: I also noticed that he always started each pull at 2500, so that contributes to the later onset too.
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Old 06-12-2012, 07:55 PM   #14
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I still hate 76mm compressors. I've never driven a car with a 76mm compressor wheel that I thought was even remotely driveable.
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Old 06-12-2012, 08:08 PM   #15
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18psi it will be fine depending on your HP goals.

Are you building your motor again?


If I were you I would make a nice BW 8374 out of cardboard and cheese and run e85 and make 800hp.
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Old 06-12-2012, 08:19 PM   #16
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I thought they made them out of tin foil and unicorn dust these days?
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Old 06-12-2012, 10:04 PM   #17
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No offense Sav, but I think you're just hating because you think it sucks. I am by no means getting offended or defensive, I've thought long and hard (tehe) about this setup and highly doubt I won't like it, but the graph isn't lying, and neither is Scott or Matt when they say it feels good with his setup. Other people I've asked (not on this forum) too.


What cars have you driven with the 76 comp?
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.
I already know it will be an improvement over the 30r which torque peaked at 4700 and made 200tq at 4k (and I loved that powerband too btw)

*edit: and lastly, what do you think the t3 housing will do for the turbo? Help or hurt it?

Last edited by 18psi; 06-12-2012 at 10:14 PM.
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Old 06-13-2012, 01:17 AM   #18
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I think it will effectively do the same stuff as cams would do, and adjust your power range further upwards. It'll likely flow better. Have you seen a turbine map before? I have NFI how to read it, but somethign something it flows more top end
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Old 06-13-2012, 03:00 AM   #19
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Quote:
Originally Posted by 18psi View Post
No offense Sav, but I think you're just hating because you think it sucks. I am by no means getting offended or defensive, I've thought long and hard (tehe) about this setup and highly doubt I won't like it, but the graph isn't lying, and neither is Scott or Matt when they say it feels good with his setup. Other people I've asked (not on this forum) too.


What cars have you driven with the 76 comp?
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.
I already know it will be an improvement over the 30r which torque peaked at 4700 and made 200tq at 4k (and I loved that powerband too btw)

*edit: and lastly, what do you think the t3 housing will do for the turbo? Help or hurt it?

stop being a puss and just run the damn thing. T3 will make it less fail and it puts the good in it.

answer my question bitch are you gonna build the motor or not. if you run e85 seriously you should be able to hit 500hp and make me sad



Quote:
Originally Posted by Orion ZyGarian View Post
I think it will effectively do the same stuff as cams would do, and adjust your power range further upwards. It'll likely flow better. Have you seen a turbine map before? I have NFI how to read it, but somethign something it flows more top end

Go kill yourself florida trash
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Old 06-13-2012, 03:08 AM   #20
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You sound upset. Do you want to talk about it?
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