2871R goes rather nicely...

[repo]

On atp site there is different comp map.

http://www.atpturbo.com/root/maps/images/gt3071rcompress.gif

Most likely the one on Garrett site is the correct one. Still, I do not care if You believe it or not. I have done lots of setups with way over 500hp and 55mm impeller, so the size of the inducer really does not limit the horsepower to 450.

Remember, where the map ends, is not the ultimate maximum of the compressor. They do stretch, but only if turbine allows them to.

[A80Avant]

that map that you posted repo is the GT30R,meaning GT3076R ( 57mm inducer 76mm exducer on compresssor side)
I had done the same mistake when buying the turbo...

However,the 3071R with the 0.63AR does not have too much stretch in it... have you tuned many cars with that turbo that made 500hp?

it seems that a bearily can reach 430hp on high boost and EGTs allowing.

Remember it is not always about a car with a full 3inch decat,track oriented etc

[repo]

I do not use Garrett bb stuff, not anymore. I have only experience in participating in Kalsket's setup. We also did 560hp from a 1.8T with gt30r, 55mm impeller, I think. It was four years ago. Or something.

What I'm trying to say here, it is not the compressor, that limits Your setups, but something else. Usually it is the turbine, but of course those You mentioned have effect as well, catalysts, catbacks, etc.

[A80Avant]

so basically turbine needs to be a bit bigger to be able for the turbo to have more room for power,right?

[repo]

Spot on.

[A80Avant]

CT358 here i come then!

[S2central.net]

A bigger turbine - like the 0.82 A/R on the GT3071 family has higher top end power capability for sure - assuming good zorst of course... But everything else being equal - running the 0.82 turbine will have more lag (take longer to spool) than the 0.63 turbine. Its very rare you get some upside on a turbo without a downside somewhere else.

I can read compressor maps all day long, but I find the turbine maps a bit trickier to 'click' in my tiny mind... They are really only valid if the turbine allows the compressor to work in the expected / desired way... And if the the turbine is too small then the maximum potential of the compressor may not be achievable. Maybe Repo or some other guru can help with this - just with some rules of thumb for selecting a suitable turbine size for the desired performance level.

[maRS2]

In the diesel world they mesure the ratio betwin Intake pressure (boost) and Exhaust manifold pressure ( EMP) to choose the right turbine.
They plug a Boost gauge on the EM to monitore the EMP.

Just an idea

diesel talking about EMP:

http://forums.tdiclub.com/showthread.php?t=195011&highlight=emp

[EspenW]

The RPM seems spot on, it's the speed output that's shot.

Yep, pretty weird. I would have expected speed to be spot on, but max power around 5900rpm seems reasonable. Strange stuff.

[karlblues2]

When fitting a 2871r does it have the same problems as the 3071?

Does the hot side get in the way, meaning the engine had to be raised?
Does the downpipe need extending to reach the turbo?

Cheers

Does anyone know the answer to this question. I'm about to buy one of the turbo kits from 034motorsport, but assumed it was plug and play
Raising engine and realigning exhaust manifold etc is more work than my little brain can cope with

All help appreciated.
P.S. Does anyone have a comparison between the 2871 and 3071 on the forum? (With or without 034chipset) or with s2centrals if they have one. (Hint hint Paul )

Cheers
Karl
Oz

[popdemonic]

Does anyone know the answer to this question. I'm about to buy one of the turbo kits from 034motorsport, but assumed it was plug and play
Raising engine and realigning exhaust manifold etc is more work than my little brain can cope with

All help appreciated.
P.S. Does anyone have a comparison between the 2871 and 3071 on the forum? (With or without 034chipset) or with s2centrals if they have one. (Hint hint Paul )

Cheers
Karl
Oz

I have 2871 on my UrS6,there's only issue on compressor housing touched up the stock airbox.I even tried to replace the front motor mounted.but didn't help.
So when I need to get the air filter in,I need to remove the metal sheet heatshield
first.put the air filter in and the cover back also needs 2-3X times compared to stock K24.

[Rusty]

The problem on the Coupe & Avants is that the hot side hits the chassis leg. I seem to remember that the 28 and 30 share the same hot side so it will be tight if nothing else.

[karlblues2]

Thanks guys. But as long as it fits, I'll be fine
Any opinions on which is best for low down response and drivability?
Cheers
Karl
Oz

[Jamo]

If you use a Wagner EM you shouldn't have the problem with a .63 hotside

[Sonic]

or go RS2 route