JMortensen Posted October 21, 2006 Share Posted October 21, 2006 I wonder just how smooth the airflow on the S-30 roof really is... it might pay to realize that the Mitsubishi windshield is much lower angled... the transition to the roof is flush... they can make use of air flowing very near the surface of thier roof... We may find that such small-short VGs show no effect... It might make more sense to address the front edge of the S-30 roof more than the back edge... The S-30 roof's rear-edge is a smooth transition anyway... Same thought occured to me. The weatherstrip has a big bump in it for the chrome strip too, so that's an extra lip right before the roofline. Might makes sense to hold the windshield in with tabs like on a real racecar and try to get the glass as flush as possible to the body line, although I don't think you can use those things with glass (or can you???). Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted October 21, 2006 Share Posted October 21, 2006 Yes, and the hatch has a bump in it at the top of its glass as well. I am thinking at this point that there is NO clean air flowing on the roof, hatch, and side window, surfaces of an S30. There are just too many "speed bumps" for the airstream such as, window trim, rain rails, wipers, mirrors..... Experiments with duct tape over the trim, and top and side streamers, would be truly revealing. Quote Link to comment Share on other sites More sharing options...
bjhines Posted October 21, 2006 Share Posted October 21, 2006 Here is a movie that has a 3 second clip of airflow over the S-30 Quote Link to comment Share on other sites More sharing options...
JIM73240Z Posted October 22, 2006 Share Posted October 22, 2006 the video is a little blurry but it looks like the air is still close to the car in a smooth flow untill about halfway down the hatch, there it gets very turbulant. i think that the vgs at the top of the roof would help bring that air down farther and get more smooth flow over a spoiler. just my observation. jim Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 22, 2006 Share Posted October 22, 2006 That didn't look like very useful info to me. 1st it wasn't an actual car, it had no firewall and looked like basically a cutaway of the external shape of the car. 2nd it looked like whatever fluid it was in was moving very slowly. Maybe it's different when you use a fluid instead of air, but that stuff looked like it was flowing past at ~5mph. Something tells me the results might be a little different with air at 100 mph with a firewall and a drivetrain, etc. Quote Link to comment Share on other sites More sharing options...
bjhines Posted October 22, 2006 Share Posted October 22, 2006 It was a 2 dimensional model... They used 2 plates of plexiglass with a stick outline of the car sandwiched in between... The fluid is water, glycol, or oil with glitter... It is common to model highspeed airflow on a smaller scale using a liquid... the inside of the car is open for simplicity sake... although there are openings in roughly the same locations as the firewall and radiator pan... they are more concerned with how the car moves air out of the way... I see that the windshield area builds up a lot of turbulence in front of it... I can also see that vortexes break off and flow over the roof and disturb air all the way to the rear... It also appears that airflow over the roof and hatch are pretty similar until about halfway down the hatch... there it begins to break away... The rear clip has flow from top and bottom turning around and hammering the taillights and hatch rear edge with high speed airflow... We KNOW this is true in full scale... this has been documented by literally THOUSANDS of owners complaining about exhaust fumes... I am so tempted to make my own 2D model.. It would be fairly easy using plastic strips and plexi glass... I would not be too hard to figure out which liquid and flow speed is the best for this type of model... You could test rear lips, angles, heights and see how that really affects airlfow behind the car... I am building my new car.. Someone take this up.. I don't have time.... Quote Link to comment Share on other sites More sharing options...
veritech-z Posted November 4, 2006 Share Posted November 4, 2006 I just went to the Tampa International Car Show, and Subaru had a WRC STi on display. I thought the spoiler on that car might interest some people that were involved in this discussion. I also have some pictures of the roll cage, if anybody wants them. There is a small spoiler at the top of the rear windshield also, which seems to be just like the one that comes on the over the counter STi. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted November 5, 2006 Share Posted November 5, 2006 Found something for you guys.... Must read on vortex generators and automobiles http://www.mitsubishi-motors.com/corporate/about_us/technology/review/e/pdf/2004/16E_03.pdf Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 5, 2006 Share Posted November 5, 2006 Excellent article and very pertinent to the discussion. We started using it on page 4 of this thread... Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted November 5, 2006 Share Posted November 5, 2006 aww son of a monkey LoL.. i was doin a search for Diffusers and Vortex generators for a class project and found the link.. Oh well.. haha Quote Link to comment Share on other sites More sharing options...
bjhines Posted November 8, 2006 Share Posted November 8, 2006 I have an announcement... I found a wind tunnel for rent... $700 for 3 hours... The car has to be attached to the base plate.. apparently it is pretty involved... The stopwatch starts when they spin up the turbines... apparently they take about 5 minutes to get up to speed... airflow can be temporarily diverted to allow changes to the spoilers and such... the idea is to use ONE CAR... and have a bunch of parts ready to swap on and off for testing... The system measures lift/downforce per wheel, drag, and stability over a wide range of windspeeds... they also have smoke generators and a smoke wand for airflow checking... pressure sensors can be attched to points inside brake ducts, wheel wells, and engine bay... etc, etc, etc... It looks like a bunch of NC boys are getting together for a real test... get your ideas ready... we are going to resolve these things in a scientific manner... Quote Link to comment Share on other sites More sharing options...
JIM73240Z Posted November 8, 2006 Share Posted November 8, 2006 sweeeeeeeeeeeeeeet. go get um. jmbo Quote Link to comment Share on other sites More sharing options...
260DET Posted November 8, 2006 Author Share Posted November 8, 2006 $700 for three hours in that sort of wind tunnel sounds like a real bargain Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted November 8, 2006 Share Posted November 8, 2006 that is an awsome price! man I'd love to see some video of this! Quote Link to comment Share on other sites More sharing options...
veritech-z Posted November 8, 2006 Share Posted November 8, 2006 I would love to see a g-nose vs typical lower valance style airdam test! also the duck bill vs whale tail would be good to see. Video and some stills for posterity would be fantastic as well! Quote Link to comment Share on other sites More sharing options...
Sven Posted November 8, 2006 Share Posted November 8, 2006 I have an announcement... I found a wind tunnel for rent... $700 for 3 hours... ...It looks like a bunch of NC boys are getting together for a real test... get your ideas ready... we are going to resolve these things in a scientific manner... This is big stuff man. Damned exciting news! Finally, something to take the place of the biggest Datsun gray area. I'm sure I wouldn't be the only one willing to pitch in on the cost of tunnel time. It would be fantastic to see which spoilers and airdams helped or hurt. Likewise with items like the Pantera hatch. Trickier issues would be things like flushing the drip rails. Who ever heard of quick release drip rails? It would be wise to start lining up people to contribute parts to test. I would be willing to lend my brand new whaletail for testing. (Hell, I may never use it anyway) Your place in the annals of Datsun history will definitely be secured if you can pull this off. Quote Link to comment Share on other sites More sharing options...
bjhines Posted November 8, 2006 Share Posted November 8, 2006 Well... the Tunnel is in NASCAR town... Mooresville NC... It was designed to test race cars at speed... The real trick here is that we need PARTS!!!!... Mark, Roddy, Tom, John and I are getting together for this event... What we really need is some more aero parts... We all have our own favorites on our own cars... but we need some raw parts that can be mocked up and quickly attached and detached to the test... Quote Link to comment Share on other sites More sharing options...
veritech-z Posted November 8, 2006 Share Posted November 8, 2006 Bj, why don't you guys list what you've got pooled between you, and then if anybody has something you don't, they could maybe make arrangements to get it there? Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted November 8, 2006 Share Posted November 8, 2006 AWESOME!!! How would you make the parts to quickly attach and detach? Dzus fasteners? Lots-o-velcro? or just screws? Quote Link to comment Share on other sites More sharing options...
bjhines Posted November 8, 2006 Share Posted November 8, 2006 double sided foam adhesive tape... and a few sheet metal screws so our nice parts don't get crushed against the excluder screens... What we have is a body that we can drill and cut... it is rusty... attachment will not be a problem... that is what will be secured to the test bed... We have these parts to assemble rear lower diffuser, underpans, a urethane front valance/air dam, one type of front splitter for the urethane airdam, we have one type of fiberglass hood (the new one with the trans am style ram air scoop), short MSA style rear lip spoiler BRE(MSA) type rear spoiler custom 6" aluminum rear spoiler(will be built for this test) gill vented fenders (will be built for this test) Type 3 side skirts ZG flares You guys want a G-nose tested??? we will have to work out sending me one shipping prepaid and insured... It should not be a show quality piece... we will need to drill a few small holes and get it to fit up correctly, and it may get a few scratches in all of the handling it must go through... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.