Urq questions

[quk@sievers.com (Phil Payne)]

In message <199703160802.AAA23437@kim.teleport.com> John Karasaki writes:

> Well, besides being annoying, the exhaust leak won't hurt anything.  It
> probably affects performance, but not in a noticable way.  I have a new 1
> piece stock exhaust manifold on my urq.  It was installed by the previous
> owner when he had the new head installed.  If I had had this done, I would
> have gotten the new two piece manifold that comes on the '91 turbo,
> non-quattro 200's or the Dialynx performance manifold sold in the US by TAP.
> Either option is expensive, but you only want to do this once, so why go
> with the stock part that WILL fail again?  I think the 2 piece is about $600
> and the Dialynx is about $750.  Removal/ replacement is not challenging or
> difficult, just time consuming.  My mechanic has a 90 deg. angled drill so
> that he doesn't have to pull the head to drill out the broken exhaust studs
> (you are bound to encounter this).

Some notes on Dialynx.  They have now sold well over a hundred of these 
manifolds and the vast majority have been trouble-free.  I only know of two 
installed on high-compression engines - mine and John Robinson's.  John has
had very serious manifold warpage problems, and I have a pronounced "tick" 
on a re-warming engine.

John's first manifold, and my manifold, were installed by a rookie at BR 
Motorsport and the job was seriously botched.  Torques were wrong or 
non-existent, cables misrouted, etc.  One of the turbo oil feed gaskets on 
John's car was installed upside down, constricting the oil flow and blowing the 
turbo, etc., etc.
 
So we were both happy to accept that the problem was _not_ immediately with the 
manifold.  It's fair to say that Dialynx Performance stood by their warranty 
and even undertook remedial work on issues that were not their fault.  They 
replaced John's first manifold without question.  I have so far not asked them 
to take any action on mine.
 
The problem is that John's _second_ Dialynx manifold has warped - so badly that 
you can see the warp with the naked eye if you look along the face.  All of his 
manifold studs are now installed via helicoils.

So far, this warpage has only been _proven_ on John's car.  It is _suspected_ 
on mine.

Dialynx have honoured (more than honoured) all of their obligations as 
suppliers - neither John nor I have any criticism of their attitude or 
service.  They're good people to do business with.  A question remains in both 
our minds about the Dialynx manifold on an MB (high compression) engine.
 
There are two technical issues:
 
a) The Dialynx manifold does not have the cast-in tripartite division that the 
original Audi manifold has on the turbo port.  Overall, it's a _very_ much 
simpler casting - although everyone who's examined one comments on the high 
quality of the workmanship.
 
b) The ports on the Dialynx manifold are slightly larger than on the Audi 
manifold, giving a step between the head and the manifold.  This is supposedly 
to improve gasflow, but it also makes it difficult to align the manifold so 
that the gasket's flame rings are properly trapped between the head and the 
manifold.  On John's second manifold, marks clearly indicate that this was 
perhaps part of the problem.  In our opinion, Dialynx really _should_ supply 
their own gasket.
 
John is now running with a two-part manifold, but is still on the running-in 
programme after a complete engine rebuild unrelated to any Dialynx issues.  
It's worth pointing out that his car is high-mileage at 155k and has been 
tweaked a little (perhaps to 220bhp - 200 is stock for an MB).
 
My own car is now doing less miles than before, although it's also 136k.  I 
don't feel I've properly stressed the Dialynx manifold yet, because my car's 
performance has been below par for a while.  Hopefully I'll get the remaining 
problems fixed over Easter and then we'll see.

Over here, BTW, the Dialynx manifold is much the _cheapest_ of all the options.
  
> Last question, for this round at least.  How do you know if
> >the turbo is either going or is already gone?  Any suggestions for the best
> >replacement for this?  Additional info for you to consider.  The block is an
> >87 5K turbo block.  It was put in at about 60k miles.  Original block thru a
> >rod.  All parts of the original engine were used when rebuilding the engine.
> > Only the block was replaced.  I still have the dual oil filters.  The only
> >other modifications are blue lite spark plug wires and a superchip from
> >Superchips Inc in FL. 

Standard advice (sorry for BW) - pull the turbo to intercooler hose at the 
intercooler end, and feel inside the intercooler.  You should feel no grit.
 
Once that test has been passed, do a standard boost gauge run.  Don't trust any 
boost gauges installed in the car - attach a separate one.  It's just a T-piece 
in one of the hoses off the manifold, with a small thick-walled tube led to 
the rear of the bonnet, out and in through the passenger window.  I don't know 
the recommended speeds and gears for an 87 5k, but someone can doubtless 
post them.

One final note on manifolds.  I asked a German garage if they had an ur-quattro 
manifold in stock, and the answer was: "Of course".  I queried this, and was 
told that they stocked a complete set of "Verschleissteile" for every Audi.

So there you have it - manifolds are "consumables".

--
 Phil Payne
 phil@sievers.com
 Committee Member, UK Audi [ur-]quattro Owners Club