Ron has a Shark Injector so we had the option of testing with factory
or Sharked software. Because the gains seen
from intakes tend to occur higher in the RPM band we decided to test using the Sharked software to increase the
rev-limiter. This was the only other power train mod on the car.
Once again measuring the actual airflow that the engine takes in was
very easy using OBDTOOL. To try to keep
both of us from ending up in jail ( Ron had to go to court today anyway) we made all runs in second gear. When
I'm logging RPM against MAF (mass air flow) I get around 2.5 updates per second out of the DME. Since the
M-Coupe accelerates so hard I only get data points every few hundred RPM on a single run. This wouldn't result
in a very smooth curve We overcame this with multiple runs and merging the data together to get smoother curves.
We watched air temp on all the runs with a Radio Shack outdoor temperature
probe run to right next to the ITG
filter on Jim's setup. On the factory airbox we put the probe inside the box on the 'dirty' side of the filter.
10 runs Jim C. intake
10 runs factory intake
10 runs Jim C. intake again
ASC+T was turned off for all the runs.
According to our R/S gauge the air temperature was very consistent throughout
the test. Within a degree of 68
degrees for all the runs.
The chart above tells the results. I used the first set of 10 runs with
Jim's intake for that plot. The second set of 10
runs with Jim's intake were similar. There is a little 'weirdness' to the curves because they are composites of so
many runs but above roughly 3500 rpm Jim's intake consistently outflowed stock.
A quick breakdown:
Around 3k the numbers are all over the place. I'm guessing VANOS is
changing right around this point and the
reason the numbers are so scattered is simply because of that. I saw something similar testing my car back when I
still had the DISA manifold in place.
Around 3500 rpm Jim's flows about 2% higher
Around 4000 rpm it flows about 6% higher
Around 4500 rpm it flows about 7% higher
Around 5000 rpm it flows about 4% higher
Around 5500 rpm it flows about 5% higher
Around 6000 rpm it flows about 4% higher
Around 6500 rpm it flows about 4% higher
Around 6800 rpm it flows about 2% higher
Around 6900 rpm it flows about 2% higher
These numbers vary slightly depending upon which data points used. I
tried to pick the closest RPM points out of
That the Jim C. intake gains jumped up pretty quickly then started slowly
coming back down makes me wonder if
something else isn't restricting max flow on this engine up high. The Ve is down about 19% at 6400 rpm compared
to 4500 rpm and is down 26% at 6900. For comparison a Fogged 1.9l only drops about 1% going from 4500 rpm to
6400 rpm. The 3.2l of course requires much more air then the 1.9l. But if you could reduce the Ve drop on the
3.2l to a comparable level as the 1.9l it would be devastating up there.
Since I helped remove then re-install Jim's intake I got a pretty good
look at it. It is built very nicely and really
does integrate well under the hood. It sounds fantastic when you nail it from within the car and from past
experience it sound great from outside the car as well.