OlderThanMe Posted May 27, 2006 Share Posted May 27, 2006 I have my 1/25 240Z scale model and am building a wind tunnel right now. I am going to play with different front end designs and spoilers. I am going to use a digital scale to measure drag and one to measure downforce. Give any ideas you have for different front ends. I am going to make the different air dams and maybe a g-nose out of poster board paper. My fan can make a scale 100mph in my 8" X 4' tube. I am going to use cooking flour as my smoke since I am too poor for a smoke generator. I'll post some pics of my progress as I go along. Quote Link to comment Share on other sites More sharing options...
jdizzy204 Posted May 27, 2006 Share Posted May 27, 2006 very cool. keep us posted Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted May 27, 2006 Share Posted May 27, 2006 Very cool. I think one major problem you will have measuring lift is getting the air flow into the engine compartment correct. Zeds have a huge friggin air scoop called a radiator opening that brings in a lot of air and causes significant front end lift. And for drag you will need something that measures how hard the car is being pushed backwards, not lifted. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted May 27, 2006 Author Share Posted May 27, 2006 I am going to cut out the solid plastic radiator that the model has and probably replace it with some fine screen. I will have a string going from the front somewhere forward over a pully, and down to a weight sitting on a digital scale. The amount the weight on the scale that is reduced is the amount of drag. Then just some math to get it to full scale. I will be doing the same thing with another string setup for lift measurement. Quote Link to comment Share on other sites More sharing options...
mrparks Posted May 27, 2006 Share Posted May 27, 2006 Why not just poke holes through it with a hot needle? That would establish airflow through it, and provide a little resistance. Most cars have a high pressure area between the grille and the radiator, which would lead me to believe that air is not pushed through the radiator fast enough, and what is pushed through becomes trapped in the engine compartment and creates lift. I could be wrong. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted May 27, 2006 Author Share Posted May 27, 2006 hmm...interesting idea. I am going to play with different ideas with belly pans and diffusers once I do the first tests with regular stuf like different air dams and spoilers. Quote Link to comment Share on other sites More sharing options...
rubin Posted May 28, 2006 Share Posted May 28, 2006 could you fit a 1:18 scale model in your wind tunnel? Its larger and has more detail so it would be easier to work with and more realistic i was thinking about getting a 1:18th to mold custom fenders and such. i checked ebay and they're not too expensive ps. could you show pics and information about your wind tunnel, I'm very interested edit: just checked ebay, roughly 20 dollars plus shipping for the die cast and 1:18 is available in die cast while 1:12 is available in the "build yourself" kind Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted May 28, 2006 Author Share Posted May 28, 2006 I don't think a 1/12th would fit. Or at least not fit where areodynamics would be rihgt. I have a 1/18th cast metal viper that I am going to stick in there also. It is probably the largest size I would want to fit in there and still have enough room around the model. Quote Link to comment Share on other sites More sharing options...
RB26240Z Posted May 28, 2006 Share Posted May 28, 2006 Very interesting, keep us updated, pics and more pics. Henry Quote Link to comment Share on other sites More sharing options...
Cruez Posted May 28, 2006 Share Posted May 28, 2006 You might be able to use a fog machine for a smoke generator... Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted May 28, 2006 Author Share Posted May 28, 2006 I had thought of one of those but my buget is still very small...just dropped a huge wad into my Z and can't afford a fog generator. Maybe I can borrow my friend's fog generator. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted May 28, 2006 Share Posted May 28, 2006 This may be a dumb question... but, how do you scale windspeed? Would 100MPH become 100mph/18??? Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted May 28, 2006 Author Share Posted May 28, 2006 yes exactly. Except I am using a 1/25 scale model. My $12 fan gives about 4.2 mph which is 105.9 mph at scale speed on the low fan speed. On high I get like 139 scale mph. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted May 28, 2006 Author Share Posted May 28, 2006 speed in feet/minute. just before setting it up stable. I got upwards of 400 fpm once the car was in there. a piece of aluminium .025 thick that I got at home depot for like $7...rip off!!! I am building the model now. The fan is going in this pic. Quote Link to comment Share on other sites More sharing options...
olie05 Posted May 28, 2006 Share Posted May 28, 2006 I'm with rubin, The largest model will give you the best realism. I would suggest a better fan, and seperate scales on the front and back wheels to measure lift/downforce. Also, how are you going to set the car up so that it has very little rolling resistance to accurately measure drag? Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted May 28, 2006 Author Share Posted May 28, 2006 this version of the tunnel is just for preliminary testing plus I already had this size model. I may get a 12" tube for larger models and use a regular box fan. Quote Link to comment Share on other sites More sharing options...
TheNeedForZ Posted May 28, 2006 Share Posted May 28, 2006 Flour is not fine enough to comply with air stream in that kind of wind. I was going to suggest heating up mineral oil for the smoke but then I though about using an incense. Burning an incense will give you a very controllable stream of smoke. If one is not visible enough you can burn more; it's cheap too. You can get incense in many places, mainly those new-age aromatherapy stores. That or a Buddhist temple. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted May 28, 2006 Author Share Posted May 28, 2006 yeah...they have it at the citgo gas station that is owned by some indians...not native americans...indian indians...just not to confuse... Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted May 28, 2006 Author Share Posted May 28, 2006 I am gluing the motor together now. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted May 28, 2006 Author Share Posted May 28, 2006 gluing the parts together using the tunnel to dry the parts...and the viper. I have been able to see the difference in wind speed around the viper using my little air speed tool. I think we have some incense here so I'll se if I can get hold of some. Quote Link to comment Share on other sites More sharing options...
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