NTS2KOC Road Test MajorHavoc Headrest Wind Blockers

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NTS2KOC Road TestMajorHavoc Headrest Wind
Blockers

• A wind-breaking analysis.

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MajorHavoc Headrest Wind Blocker?

• A pair of clear lexan sheets
• Cut to fit behind the cheese graters in your
  headrests.
• A snap to install
• Low cost (20)
• Nearly invisible

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One Minute Installation

• Literally a snap
• Slip fingers under plastic headrest backing, tug
  firmly. Backing snaps off.
• Rest Wind Blocker against cheesegrater.
• Snap backing back in place.
• Ready to go!

1. Remove headrest backing with a firm tug.
2. Wind Blocker in place. Note four holes for
backing snaps.
Note Blockers are clear lexan, but since we were
using demo units, we left on the peel-off
protective wrap, which looks blue
3. Backing has four snaps. A firm tap or squeeze
reinstalls.
4. Backing back in place, done!
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Questions to be Answered

• Do the Wind Blockers reduce wind in the cockpit?
• Do they reduce noise in the cockpit?
• Do they reduce the wind chill effect in the
  cockpit?
• Are the Wind Blockers worth it?

But how can we find out?
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Test Methodology

• Measure wind speed and ambient noise directly in
  front of the passenger head rest
• Test various configurations
• Windows up or down with
• Wind Blockers installed or removed at
• 25 mph, 40, 55, 70 and 85 mph (i.e., speeds
  equivalent to funeral, school zone, Dallas
  street, Plano street, freeway)
• Compare the results
• Wind, noise and wind chill improvements?
• We provide the data, you be the judge!

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Equipment
Radio Shack Digital Sound Level Meter 33-2055
Honda S2000, MY2000 Stock, 41k Miles Top Down No
Boot Cover
Skywatch Meteos SW-3 Elite Hand-held wind meter
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Set Up
Wind speed meter, 4 from headrest grate, level
with bottom 1/3 of opening
Approx. equal to distance from grate to back of
spouses neck.
Data logging sheets
Sound level meter, pointed at headrest opening
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Procedure
For each configuration, two runs were made, one
in each direction, to minimize the effects of the
prevailing wind.

• Set windows and Wind Blockers
• Start Run 1
• Set cruise control at proper speed
• For 2 miles take sound and wind readings
• Pull over, record readings
• Turn around, do Run 2
• Change windows, Wind Blockers or speed to next
  test configuration
• Repeat for 19 more round trips

Test Conditions Ambient temp 78 Prevailing
winds NNE Windspeed 2-18 mph RPM 3500 - 4800
Sample of data logging sheet
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Location
Breckenridge Blvd. 25 mph and 40 mph runs. 1 mile
each way.
Prevailing Wind 2-18 mph
GB Highway between Hwy 78 and Renner
(Breckenridge) 50 mph, 70 mph and 85 mph
runs. 6.25 miles each way.
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• And now, finally
• The Results!

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Change in Wind Noise

• With the windows up, the Blockers reduced wind
  noise at the passenger headrest by an average of
  0.4 decibel (dB). Since dBs are logarithmic
  (each 10 dB is 2x as loud as the last), this
  reduction, though not large, is bigger than it
  appears. At 85mph, however, the Blockers
  increased wind noise.
• With the windows down, the Blockers usually
  raised noise levels. Best guess when the windows
  are down, more road noise is reflected into the
  cockpit by the Blockers.

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Change in Wind Speed

• With the windows up, the Blockers reduced wind
  speed at the passenger headrest by an average of
  45, which is significant. At 85 mph, the
  reduction was a huge 84. At 40mph, though, the
  Blockers increased wind speed slightly.
• With the windows down, the Blockers generally
  raised wind levels somewhat. Best guess windows
  down, the vacuum behind the car normally pulls
  wind over the doors and through the headrests.
  Windows up, there is more swirling behind the
  headrests, which the Blocker effectively stops
  from coming back into the cockpit through the
  headrests.

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Change in Wind Chill

• Assuming an ambient temperature of 50 degrees F,
  rolling up the windows reduces wind chill by 3.5
  degrees.
• With the windows rolled up, the Blockers further
  reduce wind chill by 1.82 degrees.
• With the windows down, the Blocker increases wind
  chill very slightly (0.2 degrees).
• Compared to windows down and no Blockers, rolling
  up the windows and installing the Blockers
  reduces wind chill by 4.45 degrees.

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Conclusions

• If you like to drive with the top down and
  windows up (as does your humble author), the
  Blockers significantly reduce wind and noise in
  front of the headrests, and reduce the cold
  neck wind chill factor.
• If you prefer to drive top down, windows down,
  the Blockers are actually slightly
  counterproductive.
• Being low cost and quick to install and remove,
  the Blockers can easily be an effective part of
  your S2000s cool-weather windows up
  configuration.

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Subjective Observations

• We noticed the reduction in draftiness right away
  after installing the Blockers, before we ran any
  tests. We almost always drive with the windows
  up.
• Any additional quietness due to the Blockers was
  not readily noticeable. But ambient noise is
  hugely and rapidly variable. The dB meter doesnt
  lie, but ears are apparently more easily fooled.
• Given the effect of cold drafts on the back of
  the neck and ears, the perceived warmness
  effect of the Blockers probably increases as the
  ambient temperature gets colder.
• My usual passenger likes knowing her driver has
  taken all reasonable steps to ensure her comfort
  during cool weather drives at unreasonable speeds.

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Other Observations

• At any speed, rolling up the windows reduces
  cockpit wind and noise significantly.

Since dB are logarithmic, a 9 reduction (i.e
from 82dB to 75 dB) is 7dB, or 40 reduction in
noise level.
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Other Noise Observations

• A passing luxury car increases cockpit noise by 3
  4 dB, the same as a Harley at 100 yards.
• A passing SUV with street tires increases noise
  by 4 6 dB.
• Full throttle acceleration at any speed registers
  87dB, the same as steady-state driving at 85 mph
  with the windows down
• At all speeds including 85 mph, running with the
  top and windows closed (up) increases cockpit
  noise by 3 4 dB. Wind and external noise is
  apparently more than replaced by trapped
  mechanical and road noise.

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Strong wind gusts occurred during these 2 sets of
runs.
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Other Cockpit Wind Observations
0.5 mph S2000 _at_ 40 mph, windows up
1.1 mph S2000 _at_ 70 mph, windows up
1.2 mph S2000 _at_ 25 mph, windows up
1.4 mph S2000 _at_ 85 mph, windows up
1.7 mph S2000 _at_ 40 mph, windows down
3.2 mph S2000 _at_ 55 mph, windows up (strong
ambient gusts) 70 mph windows down
4.3 mph S2000 _at_ 85 mph, windows down
6.8 mph S2000 _at_ 25 mph, windows down (strong
gusts)
10.3 mph S2000 _at_ 55 mph, windows down (strong
gusts)
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Strong wind gusts occurred during these 2 sets of
runs.
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Other General Observations

• Cruising at 55 mph in the slow lane on a mostly
  empty, new freeway, cars will line up behind you
  nose to tail, contentedly chewing their cuds and
  following along.
• As indications that Honda really did put a lot of
  work into the aerodynamics around the headrests
  and roll bars
• During two runs when strong wind gusts were
  present (the 25mph and 55mph runs), having the
  windows up provided excellent protection from
  noise and wind increases in the cockpit.
• The Blockers generally produce adverse results
  when the windows were rolled down.
• As long as he gets paid, the toll booth attendant
  appears not to notice that the same guy in a
  black roadster with wacky cockpit gear has passed
  through 12 times in the space of 2½ hoursor
  maybe it happens all the time.

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Never Asked Questions

• Did you connect the meters to a laptop to record
  the data?
• No, these were not meter-to-PC downloads, just
  eyeball readings off the meters displays.
• Didnt cars and trucks pass you during the test
  runs?
• Yes, extraneous winds and noises frequently
  intruded, but we made efforts to delete them
  from our readings
• Is this a scientifically valid test?
• No, due to the above, the use of hobby meters,
  and the amateur statistical analysis.
  Unfortunately, I lent my wind tunnel and anechoic
  chamber to NASA last year and never got them
  back.
• Do you have any background or training that would
  qualify you to perform this test?
• None whatsoever.
• So these results are invalid, scientifically and
  statistically speaking?
• Completely.
• So, then, you wont be buying the Wind Blockers.
• Wrong, SUV-breath! They work well when I want
  them most on long drives through the cool fall
  and spring air with my honey beside me