Harness the Back-Draft for Extra Punch

[HiYoSilver]

One of the benefits of a wind deflector on the SRT seems to be an improvement in aerodynamics of the car. If you raise your right hand up by your right ear you will notice it gets blown forward toward the rearview mirror. This backdraft pressure increases progressively with speed from 30 mph on up. By putting a wind blocker (Viper Baffle) on the rollbars this airstream can push in your car forward in a coherent fashion. Does the car accelerate faster?
If anyone has sensitive speed measuring equipment OR access to a wind tunnel and you are willing to test this hypothesis please let me know.
I patented the Wind Baffle in 1989 and nearly all modern convertibles are using it to advantage. (Boxster, SC430, S2000, TT, 350Z)
The Viper Baffle has obvious benefits in the cockpit but I think it is improving the way the open SRT moves through the air. Can anyone help me test this? Thanks, Bob S
Pres, Wind Baffle
you can reach me at 516-829-5941 or through WB at 888-4 NO WIND or www.Windbaffle.com

 

[jrkermode]

Any pressure being generated is being done at the expense of HP produced by the car, so the pressure won't help you accelerate faster. However it is possible you improved the aerodynamics of the car, just as having the top and windows up usually improves the aerodynamics.

You can measure overall drag with just a stopwatch by doing coast down measurements. Drive as fast as is legal, ensure you're steady at that speed, then punch in the clutch and start the stopwatch. Stop the stopwatch when you get to 40MPH. Obviously, the longer this takes the lower the overall drag on the car.

The change you are looking for is likely to be very small, so, you'll probably have to do a lot of tests, in 2 directions (to account for any wind or elevation change in the test area) before you get any reliable data.

 

[HiYoSilver]

Thanks Jrkermode I think that is a good initial test. I have had the SRT up over 150 with the Viper Baffle in place and I will try to see how the drag is effected with and without the wind blocker and take a 2-way average.(Windows up & down) Good idea-thank you! Bob S
(I know I will be much more comfortable - WITH IT in place.)

 

[HiYoSilver]

Jrkermode
I did some testing with "coast down runs" from 70mph and found for a fixed distanceabout 1/4 to 1/3 mile)......speed at end of run
without the Viper Baffle.....................55 mph
with the Viper Baffle..........................63 mph**
windows closed.(without VB).............58 mph
windows closed..(with VB).................65 mph**

I did several (7) runs with each and the speed varied by no more than 1-2 mph per run. Based on this** the aerodynamics are better with the Viper Baffle in place.
Of course, I would like to get a more standardized measure of the Cd.
Meanwhile, anyone who is going to the track to do some 1/4 mile runs with an SRT-10 who is willing to compare runs with and without a Viper Baffle, please let me know. I will be glad to provide a demo. Thanks, Bob S

 

[jrkermode]

Excellent news!

I wouldn't worry too much about the Cd. Those numbers aren't terribly relevant in the real world. Manufacturers often monkey with the rake and ride height of the vehicle to get a good number. So, who knows if yours would be better or worse than "stock". What you did, measure actual drag in real world conditions, is more relevant.

 

[HiYoSilver]

Thanks Jekermode,
I still would like to see a drop in 1/4 mile acceleration times with the Viper Baffle. It would be an inexpensive way improve performance and beat a 911 Turbo evwn will an X50 package on the road ($175 less 15%) I still have Viper Baffle demos available to help get the answer. Ben in your area (Redwood City, CA) has an ****** device which may be helpful. Thanks again I hope some people can do track runs with the SRT-10 top down. Bob S

 

[Vic]

The baffle may decrease drag, but thats all it will do.

You can't harness the backdraft for more punch, in the sense that the draft is propelling you. Thats like putting a fan on the deck of your sail boat, aimed at the mainsail! Just don't work that way.

Call me if you need me, I'll be in the study, contemplating the paradox between quantum mechanics and relativity.

 

[HiYoSilver]

Vic very well said. I am waiting for a G-Timer to arrive. I still would like some 1/4 runs at a track if it can be arranged by someone with an SRT-10. Bob S