Dyno inside a wind tunnel

Discussion in 'PSI Superchargers Tech Questions' started by shimaneed, Nov 25, 2005.

  1. shimaneed

    shimaneed Banned

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    Any of you RICH guys try putting a Dyno inside a wind tunnel to see how much h/p it takes to run you car at speed? and another thing do any of you think that the injector helps pull the car down the track as its sucking in air? i know the pipes give out down force, and if the injector does will it efect the air going over the car??? Shimmy
     
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  2. Mike Canter

    Mike Canter Top Dragster
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    You don't have to put a dyno in a wind tunnel to do that. It is possible to compute out the frontal area of the car and work out the drag coeficient and then computer how much horsepower it will take to push it thru the aire at a set speed. Performance Trends Dragstrip simulation software does that for you. We compute it all the time in the aerospace industry.

    We do have the big wind tunnel here where I work and for around $2800 an hour we can tell you exactly what your drag coeficient is. We do it for all of Ford's new cars, a lot of NASCAR cars, and sevral TF/FC teams. We also have several small teams visit
     
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  3. shimaneed

    shimaneed Banned

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    Mike, the reason i mention the dyno, is to see what happens to the air flow around the car when the motor is running, for instance dose the hat efect the areo around the front of the car with the blower sucking in air, dose the ex. afect the areo around the side of the car with each pipe pushing out 800 lbs.ea. (on a fuel car) you understand what i`m asking, i gess they could just start he motor but will it give the same results? plus there is less a chance of blowing up the motor under a load.
     
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  4. Woodchip

    Woodchip Top Alcohol Dragster

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    with the absence of actually running a car under load on a scale how do they come up with 800 lbs down force per pipe for a total of 6400 lbs down force? I have a problem with that figure. If that were true a top fuel car would leap off the pavement as soon as the blades closed on an aborted run. Also at what point does this 800 lbs load happen? Is it a constant load? a spike? or averaged? Of course how could you get 6400 lbs of load when the motor turns 600 revolutions per run or thereabouts and only fires a total of 2400 ignition cycles? I think the problems drivers have steering a car when a cylinder goes out can be attributed to raw fuel spray on the tire behind that dead hole.

    Prove me wrong by making a run with a set of weed burner headers. Heck you dont even have to buy the headers. just put a 3200 lb load on the end of the header pipe bank and you will have your weed burners.
     
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  5. Mike Canter

    Mike Canter Top Dragster
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    The computation that is normally used for a Top Fuel car is 1800 lbs per side thrust. That is 450 lbs per pipe. The pipes arre not normally turned to apply max downforce but a car will veer to to one side if a couple of cylinders go out.
     
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