November 12, 2014 at 8:22 am #36947
Good morning everyone. My 11 year old son has had his first major research paper assigned to him this year in 6th grade. He is to use the scientific method, forming a hypothesis, research and test his hypothesis, then report his findings of the research and see how those results either prove or disprove his hypothesis.
Since he and I enjoy driving our go karts together, and since I’d like him to learn some basics of engine operation, we’ve decided to explore how weather conditions effect the performance of his go kart engine, a Rotax minimax. Our plan is to record all weather conditions before track testing, then after track test, download his test drive from this mychron and log that information also. I’d ultimately like to use the AIM software to download the testing info into the software package and show different performance curves together on one graph. We will keep the jetting constant and that will be our “control” for this experiment.
Our hypothesis is, “Cool dry days are the best weather conditions for optimum performance from a 2 stroke go kart engine.” The assignment requires that we use more than one test subject, so if anyone would like to help us with some data that you’ve collected yourself we’d be happy to use it. Being in FL, we are basically at sea level no matter what track we test at, so I’d like to collect some data from other parts of the country where things like altitude effect the performance of your engine. Engine type is a factor to be considered, but none the less they’re 2 strokes and the info should be similar, albeit bigger numbers.
I realize that weather changes mean changes to the carb settings in most cases, however for the sake of this experiment we are keeping the jetting constant (162 main, RMAX rules settings for the rest of the carb circuits) so as to see different results. Once we see the difference in performance, then I can begin to explain to him how jetting changes inside the carb can compensate for weather conditions.
To anyone reading this — if you have any ideas or insights, or notice anything that we are missing or doing wrong , PLEASE post a response.
If any engine builders read this and can help us with some direction or ideas, we will of course list you in our bibliography as one of our sources.
Thanks in advance for any responses that you all provide to this thread, my son and I greatly appreciate it.
November 12, 2014 at 11:40 am #36964
I find your upcoming science experiment interesting as I had the recent joy of doing the same. We were also utilizing the minimax platform but subject was regarding the tire compound hardness on laptimes. Your subject matter goes deeper than ours.
I am assuming, from your design that you are going to be running at your home track with a fixed 162 jet under diferent weather conditions. What exactly are you going to be plotting with the AIM software. Peak RPMs and rate of change? I agree with your hypothesis however worry that since the jet covers a relative wide range of temperatures and Florida isn’t known for the temperature extremes how visible any performance changes will be. If there was a noticible difference, could you attribute the changes also to changing track conditions with the changes in temperature? That is what makes comparing to other parts of the country more difficult as well.
Being devils adovocate ( but I know those science teacher’s ;))
November 12, 2014 at 11:58 am #36966
I agree that the 162 main will suffice for us most of the time without much notice here in FL….fortunately for us we are having somewhat of a cool Fall which can give us an opportunity to test in all kinds of conditions…for example, this saturday it was about 50 degrees in the morning with about 80% humidity–cold and damp for us Floridians. By Saturday afternoon, the front had past by and the humidity had dropped into the 50% range and the temperature was high 70s – low 80s. And yes, we’d ultimately like to use the aim software to do just as you suggest — compare peak rpm and rate of rpm increase at different weather conditions….honestly can’t say if track conditions that change with the weather would effect engine performance, maybe someone can chime in on that.
Dont want to get too complicated or consider too many variables, so as not to confuse him and loose his interest. My goal is to come up with something that is fun for him and allows him to learn something about two stroke engines in the process. I may call the guys at AIM after Vegas and see if they have any good ideas.
I hear ya on the science teacher thing…this is a 10 week research project and he’s 11 years old…I didnt have the academic disipline at 20 to complete something like this! School sure has changed since the 70’s.
November 12, 2014 at 1:18 pm #36968
Andy, I believe your biggest issue will be heat cycles on tires. Your data will never be able to account for your tires, no matter how you try to slice and dice the data. We have found out over the years that no matter what, you will get slower as your keep running the same set of tires. Put on a new set and you now have skewed the data from the old set. The only way your hypothesis could be proven is by running the engine on a dyno and not entering a correction factor due to temperature, air, and humidity.
November 12, 2014 at 4:55 pm #36974
Really awesome project Andy! What a way to get a student excited about a project – tying their passion in to the lesson at hand. As a husband of a teacher that works with advanced kids and hears some of the amazing things they do, this really excites me. I will share it with her as well.
Have fun with your boy and let us know how it goes!
November 13, 2014 at 5:47 am #37002
Thanks Eric, Dan and Mr Towles for your interest and replies, we appreciate all of your input.
Mr Towles — thanks for making the tire issue clear as day for us, I think you are pointing to the same variable that Dan has pointed out in his post, that tires can possibly cause flawed results unless we were to test new tires every session which is not an option for us. I think you are correct about the only way to truly prove the hypothesis is to run it on a dyno with no values input for weather adjustments, which may be an option depending on schedule and timing. We could use that dyno run as a control result for the experiment, and at the same time introduce Matthew to what a dyno is and what it does….Thanks Mr T! See you guys around soon…planning on driving any this weekend? Bring Corey out, I could use a good humbling experience! ;-)
Fortunately for me/us, this a 6th grade science project and not a senior engineering thesis, and we’re not testing to prepare for racing, so the research will be what it will be, regardless of whether we see changes or not. After we’ve gathered the results, if we cannot see noticeable differences in our data collection due to weather conditions, then we can “turn the table” on our hypothesis and question why we didn’t find what we thought we’d find and why we think we were not able to prove our hypothesis, thus bringing about new hypothesis — How much does tire wear effect peak engine rpm and rpm increase? or more clearly, How does tire temperature effect engine performance?…and on, and on…I guess its more about an introduction to using the traditional scientific method model and seeing what arises from following that lead.
I realize there are countless variables that could possibly effect our research, however I think that bringing too many variables into the experiment for his first research project might be overwhelming and confusing for him right now. That’s why we chose weather as the variable — easy information to collect and weather does effect performance in one way or another, or so it’s been written.
We’re still open to other ideas that may produce a larger range of results, however we’ve got to keep it simple to understand for an 11 yr old. Again, all comments and responses are welcomed and appreciated.
And thanks Dan for the kind words of support, I’ll update this thread as we move through our research. Please share with your wife as you stated, I’d be intreested to know her thoughts and if she has anything additional to suggest that may help us along during the project.
Thanks again everyone for taking time to comment, much appreciated.
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