[s-cars] Rebuilding turbos

[Mark Strangways]

I am running a GT30R on a stock exhaust at a conservation 345 HP (at the 
wheels).
All seems fine, I am going to switch to a header soon, I will dyno before 
and after.

We will see just how bad the stock em is.

Mark
----- Original Message ----- 
From: "Eric Phillips" <gcmschemist at gmail.com>
To: <s-car-list at audifans.com>
Sent: Tuesday, May 16, 2006 12:27 PM
Subject: Re: [s-cars] Rebuilding turbos


>> Date: Mon, 15 May 2006 23:44:32 -0400
>> From: Eric_R_Kissell at whirlpool.com
>> Subject: Re: [s-cars] Rebuilding turbos
>>
>> Marc,
>>
>> I have never used a rebuilt turbo. In fact, I have never killed a turbo.
>> When I have upgraded, I have installed used turbos.
>>
>> In fact, I have a used RS2 turbo waiting to install. Maybe I will get
>> around to it towards the end of the month.
>>
>> I do not recall if you said, but is your car chipped? Are you more than a
>> mile above sea level?
>>
>> I would think a K24 in a stock application should last more than 200k 
>> miles
>> unless someone blew a hose and overspun it or something.
>
> Hi, Eric (you're the other Eric, LOL.)
>
> I have been contemplating the future, and I understand that sometimes,
> turbos require replacement.  We are lucky in that our turbos are easy
> to access and replace, if necessary.  Not only that, we have a lot of
> choices of how to go, in the case we want to hit the slippery slope.
> Mild, wild, Happersized stroker plum crazy, etc.
>
> After doing some small amount of research, it seems that folks are
> suggesting the head and EM are at their limits with the stock unit.
> If you go up in size at all, you need an RS2 EM.  Considering the
> bulletproof nature of the rest of the mechanicals, this seems
> incongruous to me.  I spoke to Javad at 034Motorsports, and he seems
> to think this concern is "B.S."  Now, I will allow that he is trying
> to sell stuff.  But like all other low-volume producers, aimed at a
> very small market, he can't just shoot from the lip.
>
> In my circumstance, I have a MRC Stage 2 chip and an Apikol FMIC, and
> it seems that there is a little room for a small upgrade in airflow.
> Such that in the course of a turbo rebuild or replacement, one could
> take a small step up without getting into a lean condition at high
> RPM, or exceeding the limits of the fuel pump, injectors or MAF.  Or,
> more importantly, burned exhaust valves.
>
> I had a Scirocco once - I put on a GTI EM, a modified TB and IM, and a
> bigger exhaust.  Within 100 miles of doing all that, I burned the
> exhaust valve on #4.  Had the head rebuilt, and it served for another
> 120k miles before I sold the car.  Obviously, the work didn't cause
> the problem.  The problem already existed, and the additional work
> pushed it over the edge.  Or it was coincidence.
>
> My experience with that car colors my judgement here, and it might be
> that I'm coming to the wrong conclusions.  Other folks on this list
> have MUCH more experience than I, and I have to respect that.
>
> I do not know how to get definitive answers on this question -
> obviously there are some bad experiences with just replacing the turbo
> with a higher-flow unit.  What's the cut-off?  What "higher" is "too
> high"?  I don't know.  And I'm not sure anyone else does, either.
>
> But when it comes time, I want to have all the info in hand.  And make
> a choice based on as many facts as possible.  Since this list has been
> such a blessing in other aspects, I hope that Marc and I can get the
> solid scoop on this.
>
> Eric
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