Silvia Club of NSW

Would an external gated 2871 out perform it then? or is this a case of the smaller exhaust housing is a trade off for top end flow?

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I didn’t break it, I just modified the operational status...
There are 10 types of people in this world, those that understand binary, and those that don't.

It's not just smaller housing. 3071's have a GT30 exhaust turbine as opposed to the gt28 one.

This is arguably a better all round turbo as the 2871 is considered a bit of a mismatch due to the difference in diameter of the compressor and turbine where as the 3071 brings the whole thing back in line with the old within 15% rule about in/exducer diameters of turbines and compressors.

It probably explains how the 3071 is not considerably laggier as well, as the bigger turbine can more easily get the compressor up to speed, even though it takes a bit more energy to get it moving in the first place.

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meh

Interesting... I never thought about the ratio between the 2, I figured Garrett had done the thinking for me. But yes you make a good point the closer the ratio the better the ability to turn it at the other end. I guess this makes the exhaust manifold choice all the more critical when using the 2871 on a high boost engine.

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I didn’t break it, I just modified the operational status...
There are 10 types of people in this world, those that understand binary, and those that don't.

It's important to note that there are a few different varieties of the 3071 which are very different. The one being discussed at the beginning of this thread uses a T3 exhaust wheel and a hacked T2 turbine housing. The one we've used uses the GT30 rear end (larger housing, T3 inlet, ex gate with the velocity/ballistic turbine exit). Personally I wouldn't use the 3071 with the T2 rear end however the "proper" GT30 is indeed a very very good thing.

The other reason that "15% rule" existed was due to the thrust loads through the shaft. If you're comp wheel got too much bigger than the turbine wheel you'd generate higher trust loads than the thrust bearing could cope with reliably. The advent of bb turbos made this issue redundant so thats why you see some very "mismatched" combinations with bb cores. Doesn't mean they are a good thing but it can be done.

I'd be very interested to see a proper 3071 being run on a more standard SR than what we're using to see exactly what it is capable of. What we're using utterly decimates any turbo setup I've ever seen on an SR so it would be good to figure out how much of that is engine and how much is turbo. Personally I think it would still kick some serious arse, it just wouldn't quite be as silly as our setup.

Get me a 3071 setup real cheap and we'll see how it goes on one of my SR's

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Disclaimer: I actually DO know everything

Sil80 - SR20DET 231rwkw
Silvia Race Nugget - SR20DET 225rwkw
Stagea - DeathWagon - RB25DET 185rwkw.

My Lame Gallery: http://www.toomuchboost.com/gallery/main.php

wouldnt mind seeing the power curve on your setup ! whats the lag and response like compared to say a gt2530 ?!

top secret specs ?

edit: looking on www.turbobygarrett.com, both the 3071R's have T2 turbine housings, so i take it yours isnt an off the shelf item and rather a custom unit ??

I wouldn't call it custom as a number of resellers are selling them atm. It's an HKS GT2835R really and when I was doing the research it just seemed to me to be the most commoinsense combination of wheels and housings. I did take a fair bit of time modelling the comp maps and looking at the rear end but it sorta seemed pretty obvious really.

It's not really in the same ballpark powerwise as a 2530, it's sorta a couple of suburbs over. Responsewise it's not that far off, 2530 would have it till around 3300 I'd guess, after that it's very much game over. We're trying to get to the dynoday so if we do that will probably be best for comparisons.

And yes, pretty much every engine I've done has a few things done a bit differently to others

I don't need to see it on the dyno. Ive seen it rip down the main straight @ Eastern Creek. .


Maybe the fastest 200sx in Australia


My car is going on a diet

if your car gets enough of a diet we may have to run it on high boost

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The Engine Whisperer - fixer of things

found it on the comparison sheet:
http://www.turbobygarrett.com/turbobyga ... _sheet.htm

shows the 3071R with the 60mm turbine.. strange they dont list it on the main page.

yeah i realise its not quite close to a 2530, i just wanted a feel for what it would be like on a street setup, if its ontop of the 2530 after 3300, then that is quite impressive indeed.

just out of curiosity, if you dont mind me asking, whats the most compression you have run on any SR you have built ?

There's a few turbos which work very well which aren't so obvious on the garrett website, strangely they're all using "HKS" wheels

Most comp I've used is 8.9:1

What ET and MPH?

He means fastest around a track

_________________
Disclaimer: I actually DO know everything

Sil80 - SR20DET 231rwkw
Silvia Race Nugget - SR20DET 225rwkw
Stagea - DeathWagon - RB25DET 185rwkw.

My Lame Gallery: http://www.toomuchboost.com/gallery/main.php

wasnt the drag strip
it was at the track

Whoops.

I mean what lap times?