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This is leaving the parking lot then
turning onto a highway and taking a short drive to see how steady-state
conditions would help the temperature. Talk about heat soak.
After several miles at 60 mph the temperature stabilized at 122°F...
still 34°F degrees above ambient temperature. |
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With the temps stabilized I did a
quick full throttle 0-80ish mph run. As shown, the temperature
when I lifted off the throttle was 145.4°F. I upshifted
to 6th gear, slowed to 60 and drove to see how long the intercoolers
needed to recover to the pre-run temperature--21 seconds.
The green vertical bars represent
the respective data listed for right and left cursor information.
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After the sprint run I wanted to
see what the temps would look like without much time for the intercoolers
to recover. From a stop I did a full throttle run to 80
mph, jumped on the brakes down to 40 mph, then full throttle in
3rd gear back up to 80 mph several times. Recovery time
between full throttle worked out to about 5 or so seconds.
After the 5th charge to 80 mph the intake temp was 161.6°F.
I got held up by a lumbering dump truck doing 30 mph so I didn't
have a chance to sample the recovery time. I had planned
to repeat this run after I was done but fuel was running mighty
low and I was out in the middle of nowhere so no data on recovery
time for the intercoolers for this one. |
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| I noticed while
poking around that the fog lights seemed they would be
quite effective at blocking airflow to the intercoolers.
I removed the fog lights and did runs with the grills
in place. I have not decided if I'm going to leave
the lights out or not.
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With a clearer airflow path I repeated
the heat soak run. Without the fog lights installed air
temperature peaked at 156.2°F after 6 runs. I bobbled and
let up too early while braking to 40 mph so I did a 6th charge
to 80 mph. The temps for the 5th and 6th runs were both
156.2°F. As on the runs with the fog lights in place, allowed
recovery time between full throttle was about 5 seconds.
All other conditions remained the same so, as best I can tell,
removing the fog lights allowed better airflow and reduced the
intake charge temperature by 5.4°F. |
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This time I was able to watch the
recovery time to cool off to 122°F. Unfortunately, I had
to get back on the throttle because of traffic but it had almost
cooled off... the temp reached 122°F 9 seconds after I downshifted
and eased into the throttle. Note the temperature dip shortly
after the 122°F was reached. I noticed that air temps briefly
drop just as the boost comes up except when the intercoolers are
heat soaked. I guess air quickly rushing through the system briefly
drops the temperature until pressure builds and raises the temp.
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After the car sat for 4 hours in
my garage I had to make a quick run to the grocery store. This
presented the perfect opportunity to monitor temps in daily driving
with a brief heat soak while I was shopping. Note the temp right
after I started the car: 143.6°F (after sitting 4 hours!).
Once underway the temp quickly dropped to 123.8°F which surprised
me since ambient was 8°F warmer. Ironically, the lowest
temp of the drive (a bone chilling 104°F) occurred when I dropped
a gear and stepped into it to pass a slow moving minivan. |
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And now for the killer... this is
probably a very common occurrence. I did my shopping--maybe
15 minutes, then came out and hopped into a "cooled down"
car. My "cooled down" car was ingesting air mostly
over 150°F for quite some time and it didn't really cool off below
140°F until I did a steady 40 mph for a mile or so. At 514
seconds I arrived home and sat in the driveway to simulate being
stopped at a red light; maybe your back far enough to have to
sit through the light twice... well my friends after sitting stopped
for 2 minutes my intake air temperatures crept up to 145.4°F!
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