Turbo - RS2 vs Garrett 3071?

[Dave]

On 20/11/13 12:05 pm, ³Mark" wrote:

>Hi Dave,
>
>Yes it is a GT3071.
>
>I wouldn't say it has more bottom end. The RS2 started to kick at about
>2500
>while the GT3071 is more like 2800-3000. That said, it has more kick.
>Stronger through the middle and keeps going. In theory it spools faster
>due
>to the ball bearing turbo. Certainly you can hear it still spinning after
>you shut down the engine.
>
>I have seldom had mine going well. I retained all the other stock parts,
>on
>the assumption that fuelling would be ok for the controlled boost,
>however I
>have been plagued my misfires. Generally it is not a big deal when I
>usually
>just potter about town. However after my fuel consumption went out the
>door
>I finally decided I needed to find the problem. O2 levels were ok. But it
>turned out that another ignition driver was playing up, and one cylinder
>was
>not firing, the others running rich. Unfortunately the ECU is quite happy
>to
>adjust fuelling to compensate. Anyway, replacing one of the driver modules
>with an old spare I had made an immediate huge difference. The turbo was
>working on full song for the little time you can actually operate on boost
>on public roads. In general the misfiring is a result of a break down in
>the
>ignition coils, which in turn take out the driver module. Further, I
>suspect
>that oil on the plugs can result in a misfire, which in turn stresses the
>coil insulation causing the break down in the first place. So ... turbo
>starts blowing a bit of oil ... coils start breaking down ... driver gives
>up and dies. I have replaced all my coils now. Initially only 3 were
>dodgy.
>Then another one started to fail. Now I have replaced all 5.
>
>However, now the misfire is starting to creep back in. The replacement
>module is one that was previously iffy and I think it is starting to play
>up
>in the heat.
>
>There appears to be a standard fix to these modules ... cutting them apart
>and re-soldering a wire that apparently breaks off ... so I will try that
>when I get a moment. Apparently a common fault but I am not entirely
>convinced. 
>
>Ultimate plan would be to do the full ECU upgrade. This requires an
>injector
>upgrade, I think.
>
>My car had the MTM chipped upgrade from Germany, so I think the wastegate
>spring was already upgraded, but I have not checked.
>
>I "think" you can get overboost errors running the GT3071 on the standard
>ECU, then it cuts back power for a while until it "clears" ... logs an
>intermittent overboost condition. I don't think my car is doing this now,
>but it used to be. Felt like the wastegate was sticky and went like stink
>until you came off boost and then wouldn't pick up again.
>
>I have replaced one head gasket, when air bubbles were observed being
>blown
>into the catch tank. Taylor Automotive did the job but could see no
>obvious
>signs of damage to either the head or the gasket.
>
>The other thing is that the fit of the GT3071 is REALLY REALLY REALLY
>tight.
>It is much easier if you discard the inlet filter box, which I did
>initially. But a pod filter is really noisy (woosh bang) and in the end I
>managed to squeeze the standard filter back in. I think I also changed a
>couple of the turbo couplings to make it clear the chassis rails. So there
>was a bit of fiddling. Probably more than a bit.
>
>I have also upgraded the hoses to the intercooler and I would really like
>to
>upgrade the intercooler to the 034 upgraded one. (I have a small leak in
>mine, I think from the original engine mounts being worn and allowing the
>front pully to contact the intercooler. I have tried patching it, but
>suspect its effectiveness.)
>
>Cheers
>Mark
>
>-----Original Message-----
>From: Dave
>Sent: Wednesday, 20 November 2013 9:44 a.m.
>To: Mark
>Subject: FW: Turbo - RS2 vs Garrett 3071?
>
>Gidday Mark,
>
>See this query below - what turbo did you replace your RS2 one with?
>
>Cheers
>Dave
>
>On 19/11/13 9:00 am, dgraber460 at aol.com wrote:
>
>>
>>From: dgraber460 at aol.com
>>
>>Subject: Turbo - RS2 vs Garrett 3071?
>>
>>
>>Has anyone used the Garrett 3071 to replace an RS2 turbo? The patient is
>>a 95 S6 RS2'd AAN running 29 psi & 330 crank HP.
>>I have been running the RS2 for years and loved the hi boost kick in the
>>pants, but the turbo ate itself, and I need to replace it.
>>034 says the 3071 is the "RS2 killer" with better bottom end torque.
>>Sounds wonderful - is it indeed true? If, so what do I need to do to run
>>it. I'm NOT looking at using it's full max capability of 500 hp, as I'm
>>looking for longevity and not overstressing the head. I'm already looking
>>at a head gasket on another car. I'm growing weary of trying to find
>>replacement heads after finding the infamous "cracks in the valve seats"
>>every time I pull a head for a simple gasket replacement.
>>With software to run 29 PSI, do I need to upgrade the ECU? I'm
>>considering getting the green fuel injectors (40 lb.?) to maybe help, but
>>again, I really want to stay close to where the car was just with more
>>low end if possible.
>>ANY advice appreciated.
>>TIA 
>>
>>
>>Dennis 
>>Denver
>
>