K24 vs RS2 Spool-up. RS2 Results is now turbo comparison...

[Lewis, Gary M]

Hi Tony et al,

I haven't got numbers for a K26.  I had an 1988 TQ that I swapped from K26
to K24.  It was MUCH quicker.  Other data included the 2 piece manifold that
seemed to improve high rpm response.  The MAC14's (mid 89 - 1990) came with
K24 only, and I didn't want to swap in a turbo I knew I didn't want.  But a
good test would be tests with MAC11 cars, K26 vs. K24.  There appear to be
many more K24 MAC11's running about than when I checked off the list 3 years
or so ago.

Answering your questions:

1.  I'm no sure how I'm going to do 2.2 bar yet.  Scott Mockry was thinking
about doing a chip, but I don't think he ever got around to it.  Nobody does
a pure electronic solution that I know of (i.e., chip and transducer, which
probably isn't feasible anyway), so I'll either do the resistor fakey/big
spring(resistor changes the resistance the computer sees, making it think
the boost is lower than it is), big spring/schrapnel knob (device that
reduces the air pressure the computer sees), or a combo of all three.  What
I'm waiting for BEFORE I go to 2.2 bar is H20 injection.  Car pings a bit on
91 octane now at 1.8-1.9 bar, imagine what it will be like at 2.2 bar.  I'm
thinking grenade.

2.  Above 5,000 feet I never pushed (right foot application) my K24 above
1.6 bar.  Casually speaking with no expertise or hard data, I'd say if your
live above 5000 feet, stick with the K26, or get an RS2 or K24/K26 hybrid.
Audi put an altitude checking thingy in the 1991 TQ to keep the K24 from
over spinning at altitude, as the 20V T's ran 1.8 bar factory.  If Audi was
worried about it, the issue probably has merit.  Also, Scott Mockry ran some
turbo coldside exit temps while going through Colorado's Eisenhower(is that
what it is called??) Tunnel, and was getting HOT temps, like 440F.  Woah...
You really need to ask an expert (Scott *QSHIPQ* Justenson (sp?) is one) on
the pressure ratio's of the turbo's in question.  Check the archives, we've
been talking (and fighting) over this one for at least 5 years.

Bang for the buck the K24 is a GREAT mod.  If you have altitude concerns,
I'd investigate a K24/K26 hybrid, K24 coldside, K26 hotside.  The RS2
hotside exit opening is 55mm, a lot bigger than the K24.  Break out the
grinder, get the K26 to that spec.  Also, the K24 cold side intake is 43mm
vs the RS2's 48mm, which appears to me was achieved by grinding.  Again,
lotsa btdt on the list and in the archive...

Gary Lewis
1990 200TQW, RS2 Turbo, 1991 TQ Intercooler, 1.8 bar, Bypass Valve, Euro's,
Bilsteins, Redline in tranny and diffs

Planned upgrades: H20 Injection (Aug 02), Keyless Entry (Aug 02) 2.0 - 2.2
Bar Upgrade (Sept 02)


> --__--__--
>
> Message: 6
> Date: Fri, 02 Aug 2002 15:21:36 -0700
> From: "Tony Tuzzolino" <tonytuzz at earthlink.net>
> To: quattro at audifans.com
> Reply-To: tonytuzz at earthlink.net
> Subject: RE: K24 vs RS2 Spool-up.  RS2 Results...
>
> Gary
>
> Great info.  Do you have the same numbers for the k26?  I've
> just purchased a
> MC2 car that is running 1.8 bar like yours, and enquiring
> minds want to know:
>
> 1. What are you going to do to your car to run 2.2 bar?
>
> 2. Might the k26 not work better than the k24 at that higher
> boost level (or
> would heat soak negate any gains?)
>
> I'm just looking for the best value on my next mods (esp.
> since the rs2 turbo
> is worth about half of what one of these cars is!)
>
> Tony Tuzzolino
>
> Tony Tuzzolino
>
> "It will always be better to be shot out of a cannon than
> squeezed out of a tube.  That is why God made fast
> motorcycles, bubba." -Hunter S. Thompson, Song of the Sausage Creature
>