Dyno results: 2.6 liter short block

[JShadzi at aol.com]

Yes, driving Chris's car was a real experience.  That motor has almost 110ft/lbs at 1700rpm!  The sensation of acceleration was uniqe to any I5 I've ever driven.  Imaging the acceleration you get in a 2.3 NG as peak output, say 5500rpm, well that's what this motor feels like from 2krpm all the way to 6krpm.  Just one smooth power band across the entire rev range.  The power doesn't give you that peak acceleration pull like you feel in a heavily cammed small disp. engine, the acceleration is decieving because its so linear.

Now I will qualify that its still no rocket, I'd estimate 0-60 in the 7 sec. range, but its so torquey and linear that it really makes driving it nice.

I think to get much more power out of it you'd really need to do an insane port job to get the flow up through the head and get the power up, as you can see now on the graph power peaks about 5.3krpm and begins to drop off from there, more flow would help HP increase.

Overall the #'s are decieving becuase this motor has so much torque under the curve, its a real horse, feels like a truck motor.  Revs smooth all the way to 6500rpm too.

Looking forward to seeing her out at Laguna this weekend, we'll have to see how she holds up against the beater 20v Coupe.

Javad

>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
>
>
>
>