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10-12-2024, 02:34 PM | #161 | |
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Re: ET with and without wheelie.
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Excellent point. Back in the day all we had for data acquisition was lacking in a lot of ways. The holy grail for me was in tracking ground speed. The g-meters at the time (and sadly, the most popular DA computer) did not have sample rates fast enough to give a precise view of what was going on. Yes, it would give you a general idea, but like Stahl used to say "there's a reason we don't measure bores with a yardstick". He understood how important precision was in almost every area of racing. A couple of times I ran across teams trying to step things up. Chuck Peterson had a 5th wheel with speed sensor tucked under his PM Chevelle until the IHRA made him remove it. He told me it was more of a pain than a breakthrough, since any decent amount of sideways movement would just fold it up. I was standing under the tower drivethrough during a night session at Englishtown. Harold Stout's car had a light go on from under the car in front of the right slick when they fired he engine. I had found that system previously, used on Bonneville cars - the sensor would measure the time it took for the sensor (aimed straight down towards the surface, beam aimed a bit forward) to move across the beam and then calculate the speed. I asked Donnie Gardner about it later and he said he hadn't gotten much useful info from it. That could have been whitewashing, but he always seemed like a pretty straighforward guy. To explain why I was so interested in that tech, remember that the only reliable thing we had to look at was driveshaft speed. And if you think about it, that alone tells you very little about exactly what's going on. How much, if any, of that speed was created by a slightly (or more) spinning, non-glued to the track slick? No way to tell for sure. |
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10-12-2024, 04:01 PM | #162 | |
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Re: ET with and without wheelie.
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Mic drop?
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Barry Polley 758 A/SA California Screaming! California- No place to race! |
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10-16-2024, 01:54 PM | #163 |
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Re: ET with and without wheelie.
Not to revive this thread as it seems it got a little out of hand, but I'd like to input my 2 cents as well. Just wanted to wait until it calmed down a bit.
Obviously no two cars are the same. Between peak power, converters, power curves, gearing, weight, suspension set-up, tire size/contact patch, and a host of other variables, I believe it would be impossible to determine the right way to set up every car without testing it in the real world and seeing whether a car can wheelie, needs to wheelie, and what's faster. I'd like to approach the subject from a more abstract, physics perspective, using one main principle. There is no such thing as a "free lunch." The first law of thermodynamics states that energy (and matter) cannot be created or destroyed. Within a closed system, all energy put into it cannot be removed or lost. A vehicle is not a closed system by any means, but in this case, we can make a few engineering assumptions and reduce the system to a closed system, especially considering the first 60ft of a pass are at relatively low speeds so resistances such as wind and friction are not of significance. Just think to yourself and imagine the energy it takes to lift a car off the ground with only the moment of inertia created by the rear-ends rotational acceleration on the ground, it's force being equal and opposite assuming a dead hook and perfect traction. That is a TON of energy. Now I understand there is lots of potential energy stored in the front springs of a car that help the front end off the ground along with the cars ability to drive underneath it's center of gravity as the front end goes higher and higher, further exacerbating the wheel stand. The amount of power (or energy over time) an engine makes is finite from the starting line to the 60 ft beams along with any other increment you choose down the race track. This rotational energy can be expended in many ways: Friction loss, heat, sound, etc. but most importantly in our case, acceleration. If a car has the ability to accelerate straight forward without lifting the car off the ground at all, there is no wasted energy lifting the front end against Earth's gravitational pull. Knowing the amount of energy we have to work with is finite, any energy spent lifting the car off the ground is energy we could have used accelerating the car. Again, each car is different, and a wheel stand may be necessary for your combination to achieve the traction it needs to keep the tire planted and accelerate. Along with whatever black magic science goes into making your converter work or whatever other excuse you may have for steadfastly insisting a wheelie is necessary or faster. From a Thermodynamics point of view it isn't and it can't be. In conclusion, wheelies are slow, but man are they awesome. I will continue to do them, I do not care if it's slower.
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10-16-2024, 02:58 PM | #164 |
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Re: ET with and without wheelie.
My car not stocker but a 9” radial slick would go 1.35 sixty with the front tires and 1.49 with rears when it carried them past. The 1.49 always resulted in quicker et but it is a low budget deal so probably not the ideal setup but I never minded because like many have said big wheelies are fun. My super stock buddy always said ya want to be moving forward not up said it was a waste of energy but not the case for my car. Cal-tracs, Calvert monoleafs and single adjustable QA1s on rear Calvert 90/10s on front.
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10-16-2024, 06:07 PM | #165 |
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Re: ET with and without wheelie.
Again, the OP's question was...
NOT whether they are need for your car to hook, NOT whether they are fun or not and NOT about any specific combo or car!! Last edited by 1320racer; 10-16-2024 at 06:09 PM. |
10-16-2024, 06:15 PM | #166 |
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Re: ET with and without wheelie.
How this got started was a conversion about wasted energy going up and not forward. I was of the thought that given our [stocker] kind of vehicles with a small tire and in some cases a lot of torque that to get the car to move forward the mass has to move to the tires which is a wheelie. Yes in a perfect world there would be just forward motion but given our limitations that just doesn't happen. So given every combo is different a wheelie is needed more or less given the vehicle and track condition. One thing about doing wheelies is that it should hook anywhere and you know it is moving forward.
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10-16-2024, 06:50 PM | #167 | |
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Re: ET with and without wheelie.
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So if a wheelie helps a car to hook, that will not effect your et? Stan |
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10-16-2024, 07:00 PM | #168 |
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Re: ET with and without wheelie.
I was just saying for me the higher the wheelie the quicker the et would be, has no wheelie bars. When clocked with the rears the quicker et would be. The fun in it was just a great bonus.
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10-16-2024, 07:38 PM | #169 | |
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Re: ET with and without wheelie.
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Barry Polley 758 A/SA California Screaming! California- No place to race! Last edited by Barry Polley; 10-17-2024 at 09:07 AM. |
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10-17-2024, 10:25 AM | #170 |
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Re: ET with and without wheelie.
Have been intermittently following this thread.
Has this discussion included 330" time comparisons wheel stand to none if not why???
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