Dyno results: 2.6 liter short block

[Chris Darringer]

Hello listers,

Thanks to a failed flow test (and plenty of encouragement from Javad), I
recently committed to replacing the 2.3 liter engine in my '90 80q with
a 2.6 liter short block (rated at 146hp according to Eurospec).  As
expected, this was a bolt-on upgrade.  The goal of this project was to
have a car with a bit more power and some extra low-end torque without
some of the complexities and costs of a turbo conversion. 

After two tuning sessions at the dyno with Javad, I have some results to
share:
http://www.80tq.com/images/ChrisDarringerDyno.JPG

Here are some interesting notes from the test:

(1) Max power at the wheels is 114.2 hp and max torque is 122.4.  If you
make the (overly-simplified) assumption that hp and torque are 25%
higher at the crank, then we are looking at around 143 hp and 153 lbs of
torque.  This is a bit lower than I expected, given the original
Eurospec rating.  I should also point out that a basic amount of head
porting was done, and the BlauSport 272 cam was installed too.

(2) Over 90% of the torque is available at 2k rpm, and the curve seems
relatively flat through the whole rpm band.  This is a noticeable
improvement over the original 2.3 block.

(3) The air/fuel ratio starts out fine but approaches 12 as rpms
increase.  According to the guys at ATP, 13.5 to 14 is ideal for
normally aspirated cars, so mine appears to be running rich.  This was a
surprise, since one of the biggest concerns about this conversion was
that CIS would not be able to fuel the slightly larger engine at high
rpms.  Javad attempted to lean out the engine by adjusting the CO
(values from 0 to 11mA were tried) but this appeared to have no
significant effect at high rpms.  

Special thanks to Javad for his continuous help, M&M AutoHouse in
Cambell for their enthusiasm and excellent customer service, and Chris
at Force5auto for answering my tedious phone questions over the
holidays.

As always, your questions, comments or suggestions would be appreciated!

Chris
'90 80q 2.6