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S2000.org Reviews - MajorHavoc Wind Blockers, "A Windbreaking Analysis"

Author: Paul Dippell
 


What is the MajorHavoc Wind Blocker?
The MajorHavoc Wind Blockers are precision-cut pieces of clear Lexan that install in the "mesh" headrest of the S2000's seats. They are designed to cut down on the amount of wind that enters the cabin with the top down. They are easy to install and run only $20 from the S2000 International's web store here.

One Minute Installation
The Wind Blockers can literally be installed in under a minute. First, flip the seat forward and remove the headrest backing with a firm tug. Remove the blue protective sheets from the Wind Blockers and set them in place. Note the 4 holes for the 4 snaps on the backing. Replace the backing and you are done!

  

  

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?

How can we find out?

Test Methodology
- Measure the wind speed and ambient noise directly in front of the passenger head rest
- Test various configurations:
  - Windows up or down
  - Wind Blockers installed or removed at 25, 40, 55, 70, and 85mph
- Compare the results
  - Wind, noise, and wind chill improvements?
  - We provide the data, you be the judge!

Equipment/Setup
- Radio Shack Digital Sound Level Meter (33-2055):


- Skywatch Meteos SW-3 Elite hand-held wind meter:


- 2000 Honda S2000 (stock), 41,000 miles, top down, no boot cover


The equipment was set up in the S2000 to most closely approximate the presence of a human in the passenger seat. The wind speed meter was mounted via a "goosneck" arm to be approximately where a head would be, and similarly the sound meter was mounted and aimed at the headrest:

Procedure
For each configuration, two runs were made (one in each direction) to minimize the effects of the prevailing wind. Test conditions consisted of an ambient temperature of 78F, NNE winds of 2-18mph, and S2000 RPMs of 3500-4800. The procedure is as follows:

1. Set windows and Wind Blockers
2. Start Run #1
3. Set cruise control at proper speed
4. For 2 miles take sound and wind readings
5. Pull over, record readings
6. Turn around for Run #2
7. Stop, reconfigure and repeat above steps for remaining 19 round trips...

Here is a sample of the log used:

And the location for the testing:

And finally, the results!

% Change in Wind Noise

With the windows up, the Wind Blockers reduced wind noise at the passenger headrest by an average of .4% decibel (dB). Since the decibel scale is logarithmic (each 10dB is 2x as loud as the last), this reduction, though not large, is bigger than it appears. At 85mph, however, the Wind Blockers increased wind noise.

With the windows down, the Wind Blockers typically raised noise levels. Best guess: when the windows are down, more road noise is reflected into the cockpit by the Wind Blockers.

% Change in Wind Speed

With the windows up, the Wind Blockers reduced wind speed at the passenger headrest by an average of 45%, which is significant. At 85mph, the reduction was a huge 84%. At 40mph, though, the Wind Blockers increased wind speed slightly.

With the windows down, the Wind Blockers generally raised wind speed 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 Wind Blockers effectively stops from coming back into the cockpit through the headrests.

% Change in Wind Chill

Assuming an ambient temperature of 50F, rolling up the windows reduces wind chill by 3.5F.

With the windows rolled up, the Wind Blockers further reduce wind chill by 1.8F.

With the windows down, the Wind Blockers increase wind chill very slightly (.2F).

Compared to the windows down and no Wind Blockers, rolling up the windows and installing them reduces wind chill by 4.5F.

Conclusions
If you like to drive with the top down and the windows up (as does your humble author), the Wind Blockers significantly reduce the 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 Wind Blockers can be an effective part of your S2000's cool-weather "windows up" configuration.

Subjective Observations
We noticed the reduction in draftiness right away after installing the Wind Blockers, before we ran any tests. We almost always drive with the windows up.

Any additional quietness due to the Wind Blockers was not readily noticeable. But ambient noise is hugely and rapidly variable. The dB meter doesn't lie, but ears are apparently more easily fooled.

Given the effect of cold drafts on the back of the neck and ears, the percieved "warmness" effect of the Wind 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.

Other Observations
At any speed, rolling up the windows reduces cockpit wind and noise significantly:

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 4-6dB.

Full throttle acceleration at any speed registers 87dB, the same as steady-state driving at 85mph with the windows down.

At all speeds (including 85mph), 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.

Cruising at 55mph in the slow lane on a mostly empty, new freeway, cars will line up behind you nose to tail, contentedly chewing their cud 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 Wind Blockers generally produce adverse results when the windows were down.

As long as he gets paid, the toll booth attendant appears to not notice that the same guy in a black roadster with wacky cockpit gear has passed through 12 times in the span of 2.5 hours... or maybe it happens all the time.




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 of the meters' displays.

Didn't 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 teast?
- 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 won't 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...

For a PowerPoint presentation of this review (much nicer!) please click here.



This page last updated 2/5/03.
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All manufacturer's names are copyright their respective parent companies, and in general are used without permission.
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