What Would You Expect From This On Rb25

[ARTZ]

specs

GT3071R garrett ball bearing turbo

comp housing

0.50a/r

inducer wheel diameter 53.1mm

exducer wheel diameter 71.0mm

trim 56

exhaust housing

0.64 a/r (mod 21u)

turbine wheel diameter 56.5mm

trim 84

Was told and I thought should make 260...but it isnt, thinking it would be better suited to a rb20

Edited November 16, 2010 by Arthur T3

[GeorgesR34]

should make 250rwkws

[D_Stirls]

For an RB25 i would have gone for the full sized Turbine wheel (60mm) and the 0.82A/R housing. You will probably find that you are choking the turbo.

[Dale FZ1]

exhaust housing

0.64 a/r (mod 21u)

turbine wheel diameter 56.5mm

trim 84

Was told and I thought should make 260...but it isnt

So what is it making - somewhere around 230-235?

Looks like you've got a milled (high flowed) OEM turbine housing. If so I think you'll find they're somewhat smaller than 0.63, but there is no marking on them to indicate. Might not be a good match with the rotor, can lead to a bit of choking and below expected outputs.

You might do well to consult with a turbo manufacturer/remanufacturer about housings - perhaps Hypergear can help out if that is the culprit.

[ARTZ]

yeah its making a solid 240..

and spoke to hypergear a while back who straight up recomended a bigger rear housing..

But for that amount of trouble Id consider just getting a better turbo..

might just run some e85 see what happens...I got no problems with the power ,thought it would be a tad more responsive for what it is really. And its kind of odd having a turbo that comes onto boost but doesnt really make alot more power than it did b4..It pulls hard but there's not that boost kick .Not to worry..I should stop complaining and just be happy its running again.

[PM-R33]

Sounds like new GTX turbo time

[ARTZ]

its very tempting, I dont think there is any point trying to get anything more out of this one pretty much maxed out already..

And i could probably get the same power from a 2871 with far better response

I have a bad habit of jumping in the deep end, i did plenty of research after i bought it..

Edited November 17, 2010 by Arthur T3

[Harey]

It is quite hard choosing a turbo that will suit your driving. It seems with skylines that its really hard to have both response and great top end power due to the high rpm range involved.

[Dale FZ1]

It pulls hard but there's not that boost kick .Not to worry..I should stop complaining and just be happy its running again.

It helps to know what characteristics you want before you start. Some combinations are deceptively fast ie. cover ground quickly and don't feel it. Despite the power number, it might deliver the goods if you can directly compare with something else.

I'd be interested to see a dyno sheet, even if it only tells part of the story...

and spoke to hypergear a while back who straight up recomended a bigger rear housing..

But for that amount of trouble Id consider just getting a better turbo..

Well you've already asked someone who is a specialist in the field. I wouldn't think that a housing upgrade would cost the earth, and if it stops the thing choking up high then trialling it would be worthwhile. You may also find that any loss of response is academic when you look at the entire picture.

its very tempting, I dont think there is any point trying to get anything more out of this one pretty much maxed out already..

And i could probably get the same power from a 2871 with far better response

You might be surprised what a bigger turbine housing will do, and the extra ignition timing that it allows you to run. If you went with a -32 spec 2871 all you would get is a smaller turbine rotor with the same sized compressor FWIW, I found a -31 spec (ie 48 trim) GT2871 high flow very good, progressive and fast with 225rwkW. Never looked fast but it really covered ground nicely for a road car.

Edited November 18, 2010 by Dale FZ1

[ARTZ]

Deceptively fast maybe the word for it..it is fast no doubt about it,

but it doesnt have that scare factor..It feels remarkably sedate..

Im probably just over thinking things as usual..