[urq] Looking for turbo and induction solution

[Ben Swann]

No question the turbo was petering out at higher boost levels - the noise is
disconcerting - bearing failure?  It did not fell that bad and at idle hums right along.
Under load sounds like the alternator fan hitting a belt, but that is not what is
happening - pretty sure the noise is coming from the turbo, maybe shaft twisting and
impeller hitting housing.

Anyway - I'll pull the turbo and replace - just looking for ideas to get a better
intake.  Presently the small hose makes that u-bend and no room to really work around.
Might even be good juse to fab a large intake filter behind the grill and feed that into
the turbo.  Still there is only about .25" max between intercooler pipe that one hose
goes over and the intake pipe. With wall hose thickness of almost .13 + clamps it really
is difficult to get these hoses on.  Anyone who has an UrQ knows this problem well.

The best solution might be to run a hose from the bumper - straight shot into the turbo
and somehow force air into the bumper through some filter system in there.  The cone
hose setup sounded like a Wookee and eminated a lot of weird noises - looked cool, but
not ideal.

I am not keen on reworking the intercooler, but if I found one that fit in stock
location or something that fits behind the grill, that would be nice.  After all I've
spent on the conversion a little more to get this right would be icing no the cake.

I do plan to go with the K26 rebuild - it is the larger K26 and similar I/O as the Rs2
turbo I have for my ES2 conversion.  The way I don't need to re-engineer all the oil and
water lines again which seem to lead to other sets of problems.

Ben
-----Original Message-----
From: tlum at flash.net [mailto:tlum at flash.net] 
Sent: Friday, October 10, 2008 1:44 PM
To: benswann at verizon.net
Subject: Re: [urq] Looking for turbo and induction solution

Ben,

I recall that the K24 suffers from heat soaking with a gradual loss of boost.  Been
mentioned many times over the years.  My K24 doesn't do this, but I seldom exceed 15 psi
(1 bar).

Tony
'83 urquattro #302


= = = Original message = = =

After solving long drawn out problem with fuel  delivery in my '83 UrQ using Megasquirt
EFI, etc. I now am finding issues when developing boost.  After hard run up to
Four-rings gathering:
http://www.justfourrings.com/phpBB2/viewtopic.php?t=935&postdays=0&postorder=desc&start=
0  and spirited mountain driving there was a noted progressive power loss with boost not
developing fully.  I had good boost and nice jet engine sound going up and hitting
continued 2.5+ bar, until a noticable sound like tubine blades rubbing on something
whirring sound entered into the picture.  I also noticed more oil blow, but may or may
not be related as some was coming out of the oil cap.

I think the k24 is dying - sounds OK when cold, but after 2 or three accelerations has
hard time making boost and that becomes associated with blade noise.  I did not find
anything injested, and so assume bearings are going south.  I have a few turbos and am
contemplating installing nice 26 rebuild I have so I don't have to change oil and water
feed lines.  If I do I'd like to see if there is a more sane way to do intake,
intercooler pluming routing.    Latest setup had starigh hose into turbo with cone
filter, and final test with no filter still had whirring noise.

There is pretty much an open air tract into turbo with just a cone filter and blowoff
valve - just the close proximity of the outlet hose makes for difficult plumbing and I
think going with slightly larger k26 intake and outlet will  be problematic with hoses
barely fitting on the turbo since the intercooler outlet crams right next to the inlet
of the turbo.  This is still pretty much stock orientation - one of the things that
really did not change with all the mods is the intercooler and turbo setup.

If I have to pull bumper off and go through turbo swap, just getting ideas what might be
a good approach to having a good intake solution if any.  Possible FMC in grille or
reworked intercooler that gives more clearance near alternator would help.  There is
much more room her than with CIS, but still things are very tight right at the turbo.
It seemed that there may even be a way to bring intake to turbo through the bumper as
there is a straight shot in there - anyone done this with some sort of filter system
located in the bumper with perhaps force air dam below.  

Pictures and ideas of tried solutions would be helpful.

Ben
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