More K26 in a 91 200 20v

[Ameer Antar]

well, I think Audi over estimated the need for a k26 on the KH/MC motor. 
The k24 should have been used originally. If you can get 1.8 bar at 9.3:1 
compression w/ 20 valves out of a k24, it can easily handle the 10v motor 
at 1.4 bar. Even though the 20v is higher compression, they still used more 
boost than the 10v, so really the engine is just much more controlled. I 
was just comparing airflow figures....the 10v has a much lower airflow 
number than the 20v at stock levels, so based on this a 20v could use the 
k26 more so than the 10v. Your right that the higher compression will make 
it easier for detonation, but Audi did this anyway and used a higher boost. 
Every car has a little extra room in the design so you can add a few more 
ponies. It's up to the owner to figure out how far he wants to 
go.  Although it'd be real dangerous to run an engine w/ 9.3:1 compression 
w/ 20-24 lbs of boost, fore some that's a goal, and the k26 is what's going 
to make it happen. But you'd need to have fuel system mods, 100 octane 
fuel, and a lot of guts...

-ameer


At 03:55 PM 2/6/2001 , you wrote:
> > Actually w/ a 20v vs 10v, the 20v needs the bigger turbo. The Audi MC
> > engines got K26 turbos, so a 20v which can pump in much more air, could
> > deal w/ a larger compressor. If you are using a Porsche turbo on a 10v, it
> > could surely work for a 20v. But as long as the guy's only doing 1-1.5 bar
> > boost, lag will be minimal w/ the stock turbo. But beyond that, the stock
> > turbo wouldn't be able to handle the requirements....time for a k26...a
>bit
> > more lag, but a lot more power running all the way up to 7 grand.
> >
> > -ameer
>
>Careful here, the 20V (9.3:1) is a higher compression engine than the 10V
>(7.8:1).  You can stuff a lot more mixture into a 10V before you have a
>detonation problem -- thus the 10V uses the _larger_ K26 turbo.  The K24 for
>the 20V is a _smaller_ turbo.
>
>Audi went with higher compression and a smaller turbo on the 20V to get more
>power and less lag.  The gain was primarily in the less lag, as I understand
>it.
>
>Don't compare a USA 10V with a USA 20V and assume the stock HP is due solely
>to the valves and turbo.  The USA 10V is detuned, running at 1.5 bar rather
>than 1.8 bar.
>
>I am curious if anyone knows what the euro HP figures for an '86-'88 200
>(MC) in Germany might have been?  What boost did the Euro version run at?
>
>Best,
>
>Bernard Littau
>Woodinville, WA
>'88 5ktq