2871R goes rather nicely...

[Jamo]

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.

It's not as much extra lag as you think, see Audimans Golf with a 2 ltr engine and 3071.82

I can't wait to see AndyP's stroker running the 3071 with the .82

[Ross]

It's not as much extra lag as you think, see Audimans Golf with a 2 ltr engine and 3071.82

I can't wait to see AndyP's stroker running the 3071 with the .82

Just a shame it can't put the power to the ground - should be fun when it's 4WD

Talking of Stroker's Jamo... get a move on :mischeif:

[Jamo]

Just a shame it can't put the power to the ground - should be fun when it's 4WD

Talking of Stroker's Jamo... get a move on :mischeif:

Give me a winning lottery ticket then..............

[karlblues2]

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

Hi Jamo
I have an RS2 EM and all the other RS2 bolt on stuff, (including MD147 same as Greg_S) but stock internals and am not happy with the excessive lag. Hence I'm between the 3071 and the 2871. Really not much in it cost wise. So which way to go
Cheers
Karl

[Jamo]

Hi Jamo
I have an RS2 EM and all the other RS2 bolt on stuff, (including MD147 same as Greg_S) but stock internals and am not happy with the excessive lag. Hence I'm between the 3071 and the 2871. Really not much in it cost wise. So which way to go
Cheers
Karl

You can run the 2871 to full potential on stock internals due to the lower amount of torque.

With a 3071 you can run it the same but you may have to reduce torque to save the rods.

The question then is are you going to upgrade the rods? if not 2871r and a s2central 2871 homefry

[Rusty]

2871 homefry :mischeif:

[Bram]

Or my GT3071R software which is safe for stock bottom end

[Jamo]

Or my GT3071R software which is safe for stock bottom end

Nice

[karlblues2]

Yeah, that's my issue, 034 have the easy (lazy) kits, but there seems to be better chipsets out there to support our application better (MTM, MRC and S2central homefries to name a few)
What I am after is predictable performance with low down drivability. I've had the head port matched and an RS2 gasket fitted, but I have retained stock cams. I have the 044 fuel pump, and then RS2 IM, EM, injectors, FPR and FMIC. I am running the MD147 with a MRC chipset, but the lag is frustrating, - 4500rpm before full boost. I have lost a full 30kw atw from the K24 setup below 3000rpm. Given the roads here and the off the mark and minimal lag is preferred, the 2871 might be the best route for me. I have the E36 M3 convertible for the pose and the B5 S4 Avant on it's way next week for the err family
I just need the S2 to be reliable, quick, but not all or nothing as it is now. Does that make sense?
So, I think I will go the 2871 route and acquire from somewhere:
440ccm injectors, 5 Bar FPR, 1.9 bar WG spring and the all important map to suit. Anyone any ideas where I can get this stuff apart from 034?
Cheers
Karl
Oz
PS - The RS2 MD147, RS2 oem injectors and 4 bar FPR plus a genuine RS2 homefried ECU with immobiliser (which I can't use) will be up for sale as a result of this transformation. I'll post up in the FS section once it's completed.

[S2central.net]

Do NOT need 5bar FPR...

And I've used stock WG spring on my 2871 work so far... not played with big springs on the boost map yet.

Another alternative for you is that I tweak my RS2 chipset (non-immo version) to suit your MD147... Thats surely going to be plenty quick - even on stock injectors and cams... What think ye ?

[karlblues2]

Do NOT need 5bar FPR...

And I've used stock WG spring on my 2871 work so far... not played with big springs on the boost map yet.

Another alternative for you is that I tweak my RS2 chipset (non-immo version) to suit your MD147... Thats surely going to be plenty quick - even on stock injectors and cams... What think ye ?

Hi Paul
I only went off the 034 kit. Interestingly they use 5 bar on the 2871 and 4 bar on the 3071? Go figure!

Do you think you can get the MD147 to come on boost earlier? 4500 at full boost is just far too laggy!!

Please PM me with some prices and options matey. I'm all ears
Cheers
Karl
Oz

[S2central.net]

Can you post up a compressor map for the MD147 to save me searching for it ?

4500 seems a bit late alright - but I'd need to look at it properly.

[karlblues2]

I don't have one Paul Sorry. Greg_S might though?

[S2central.net]

Can't find a map anywhere so far... might have to contact the manufacturers - it will be derived from some K27 compressor - hence the lag you naturally feel vs a K24 but thats the age old problem.

Spec on this turbo outlined as follows -

MD147 High flow K27 “Super Back” Compressor wheel, K27 modified compressor cover and seal plate assembly, 360 degree thrust bearing, modified watercooled bearing housing, left hand thread twin seal shaft & wheel assembly with cut back turbine blades. Recommended maximum boost level is 28 P.S.I.
Horsepower achieved: 404bhp 485ft lbs torque

Would need uprated rods to run this to max boost potential in the mid range - well assuming it can actually make max boost between 3 & 4000

[S2central.net]

Here's one I just found on motorgeek - posted by some dude called Josh from RI a few yrs ago - LOL. Seemingly its a K27 with 3072 compressor...